FCC ID: TSEFAU200RA Globalstar Fixed Access Unit with Remote Antenna

 

Description of the Globalstar System GS-TR-94-0001 Revision E Description of the Globalstar System December 07, 2000 Page i Description of the Globalstar System GS-TR-94-0001 Revision E DOCUMENT REVISION HISTORY Revision Date of Issue Scope A B C D E 6/3/94 12/20/94 8/10/95 2/24/97 12/07/00 Incorporated QUALCOMM Comments Updated after SRR/PDR Reviews Updated after the HLDR Reviews Update to incorporate design changes Added Photographs & Revised Services Abstract This document is written to introduce new people to Globalstar. It attempts to provide a general overview of the system and to provide some information on the design of the system. It also attempts to define how Globalstar is envisioned to operate. As such, this is primarily tutorial in nature. In the interests of brevity, simplifications are made in the material herein. There is no attempt to be totally complete or comprehensive for all cases. This document should not be interpreted as a binding specification. It does not contain requirements that should be interpreted as either complete or binding. Globalstar is an evolving system. This document will be updated as the design of the system progresses. When each revision is issued there is an attempt to represent the current thinking on the system. For binding specifications and requirements please consult the released requirements documents and the released design information. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Globalstar, L.P. 3200 Zanker Road San Jose, Ca. 95164-0670 Copyright 1997 Globalstar, L.P. All rights reserved. Printed in the United States of America. Page ii Description of the Globalstar System GS-TR-94-0001 Revision E Contents 1. SERVICES OFFERED 1-1 1.1 Service Types ..........................................................................................................1-1 1.2 IS-41 Services .........................................................................................................1-1 1.3 GSM Services ..........................................................................................................1-8 1.4 Globalstar Specific Services and Quality ........................................................1-15 1.5 External Network Supported Services ............................................................1-17 2. SYSTEM SEGMENT DESCRIPTIONS 2-1 2.1 Globalstar System..................................................................................................2-1 2.2 User Terminal.........................................................................................................2-3 2.2.1 Hand Held and Mobile Units.........................................................................2-3 2.2.2 Fixed Terminals ...............................................................................................2-7 2.3 Gateway....................................................................................................................2-8 2.4 User Terminal and Gateway Interaction........................................................2-12 2.5 Globalstar Control Centers................................................................................2-13 2.5.1 Ground Operations Control Center............................................................2-14 2.5.2 Satellite Operations Control Center ..........................................................2-17 2.5.3 Globalstar Business Office ...........................................................................2-19 2.6 Globalstar Satellite..............................................................................................2-20 3. FREQUENCIES AND COVERAGE ANALYSIS 3-1 3.1 Frequency Plans ....................................................................................................3-1 3.2 Satellite Antenna Beam Configuration ............................................................3-2 3.3 Earth Surface Coverage .......................................................................................3-7 3.4 Position Determination.......................................................................................3-10 3.5 Channel Characteristics.....................................................................................3-12 3.6 Link Analysis........................................................................................................3-14 4. CODE DIVISION MULTIPLE ACCESS (CDMA) 4-1 4.1 Introduction ............................................................................................................4-1 4.2 Diversity Combining .............................................................................................4-2 4.3 Fade Mitigation......................................................................................................4-2 iii 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Description of the Globalstar System GS-TR-94-0001 Revision E 4.4 Acquisition...............................................................................................................4-3 4.5 Forward CDMA Channel .....................................................................................4-5 4.6 Return Link CDMA Channel............................................................................4-10 4.7 CDMA End to End Performance ......................................................................4-12 5. TERRESTRIAL INTERFACE 5-1 5.1 Telecommunication Network Interface .............................................................5-1 5.2 Registration Process..............................................................................................5-4 5.3 Authentication Process.........................................................................................5-7 5.4 GSM - A Interface in Globalstar .......................................................................5-10 6. CALL PROCESSING 6-1 6.1 Call Processing between Globalstar and PLMN .............................................6-1 6.2 TIA and ETSI Call Flow Examples ...................................................................6-5 1 2 3 4 5 6 7 8 9 10 11 12 13 iv Description of the Globalstar System GS-TR-94-0001 Revision E Figures Figure 2-1 Globalstar System Integrates with Terrestrial Network ........................ 2-1 Figure 2-2 Globalstar Constellation Serves Temperate Areas .................................. 2-2 Figure 2-3 Typical Hand Held User Terminal ............................................................. 2-3 Figure 2-4 Globalstar User Terminal Block Diagram ................................................. 2-5 Figure 2-5 User Terminal Startup Scenario within Globalstar ................................. 2-6 Figure 2-6 Typical Fixed Terminal Application........................................................... 2-7 Figure 2-7 Typical Gateway Installation....................................................................... 2-8 Figure 2-8 Gateway Simplified Block Diagram............................................................ 2-9 Figure 2-9 Globalstar Control Center ......................................................................... 2-13 Figure 2-10 Ground Segment Support for Communications .................................... 2-14 Figure 2-11 GOCC Simplified Block Diagram............................................................ 2-15 Figure 2-12 Ground Equipment Support for T&C Functions................................... 2-17 Figure 2-13 Spacecraft Bus Characteristics - Highly Autonomous ......................... 2-20 Figure 2-14 Communications Payload Pictorial ......................................................... 2-21 Figure 2-15 Communications Payload Simplified Block........................................... 2-21 Figure 2-16 Satellite T&C - Compatible with Communications .............................. 2-22 Figure 3-1 Frequency Plan - Emphasizes Conservation of Spectrum ....................... 3-1 Figure 3-2 S - Band Beams .............................................................................................. 3-2 Figure 3-3 L- Band Beams............................................................................................... 3-3 Figure 3-4 L - Band Channel Frequencies .................................................................... 3-4 Figure 3-5 S - Band Channel Frequencies..................................................................... 3-4 Figure 3-6 Full Earth Coverage-Except Polar Regions............................................... 3-7 Figure 3-7 Enhanced Coverage for Temperate Regions ............................................. 3-8 Figure 3-8 Orbital Parameters for Globalstar Satellites ............................................ 3-9 Figure 3-9 Channel Characteristics Considerations ................................................. 3-12 Figure 4-1 Acquisition Search Space ............................................................................. 4-3 Figure 4-2 Acquisition Time as a function of Latitude................................................ 4-4 Figure 4-3 Forward CDMA Channel Transmitted by a Gateway .............................. 4-5 Figure 4-4 Forward Link Pilot, Sync and Paging Channel ......................................... 4-6 Figure 4-5 Forward Link Traffic Channel - Rate Set 1 ............................................... 4-7 Figure 4-6 Forward Link Traffic Channel - Rate Set 2 ............................................... 4-8 Figure 4-7 Forward Link Modulation and Spreading ................................................. 4-9 Figure 4-8. Reverse CDMA Channels Received at a Gateway................................. 4-10 Figure 4-9 Return Link Access Channel ..................................................................... 4-11 v 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Description of the Globalstar System GS-TR-94-0001 Revision E Figure 4-10 Return Link Traffic Channel ................................................................... 4-12 Figure 4-11 Forward Link Delay Budget .................................................................... 4-13 Figure 4-12 Reverse Link Delay Budget ..................................................................... 4-13 Figure 4-13 Power Control Simplified Diagram ........................................................ 4-14 Figure 4-14 Acquisition Time as a function of Eb/No ................................................ 4-15 Figure 5-1 Gateway Architecture................................................................................... 5-1 Figure 5-2 Gateway Connections to the PSTN - Flexible Interface .......................... 5-3 Figure 5-3 Registration of a U.S. based User with an IS-41 HLR.............................. 5-4 Figure 5-4 Registration of a European User in a GSM HLR...................................... 5-5 Figure 5-5 Registration of a U.S. User in a GSM Environment ................................. 5-6 Figure 5-6 Registration of a European User in an IS-41 Environment..................... 5-7 Figure 5-7 Authentication for a GSM User in IS-41 System....................................... 5-9 Figure 5-8 GSM DTAP on Mobile Terminated Call................................................... 5-10 Figure 5-9 GSM DTAP on Mobile Originated Call .................................................... 5-11 Figure 6-1 Mobile Originated Call ................................................................................. 6-1 Figure 6-2 Roaming Call Delivery - Successful ............................................................ 6-2 Figure 6-3 Roaming Call Delivery - Subscriber Busy.................................................. 6-3 Figure 6-4 Simple Call Flow, User Terminal Origination Example Using Service Option 1 (TIA Call Control Procedures) .................................................. 6-6 Figure 6-5 Simple Call Flow, User Terminal Origination Example Using Service Option 1 (ETSI Call Control Procedures) (Part 2 of 2)........................... 6-7 Figure 6-6. Simple Call Flow, User Terminal Termination Example Using Service Option 1 (TIA Call Control Procedures) .................................................. 6-8 Figure 6-7 Simple Call Flow, User Terminal Termination Example Using Service Option 1 (ETSI Call Control Procedures) (Part 2 of 2)........................... 6-9 Figure 6-8. Simple Call Flow, User Terminal Initiated Call Disconnect Example

(TIA Call Control Procedures)................................................................. 6-10 Figure 6-9 Simple Call Flow, User Terminal Initiated Call Disconnect Example

(ETSI Call Control Procedure) (Part 2 of 2)........................................... 6-10 Figure 6-10. Simple Call Flow, Gateway Initiated Call Disconnect Example (TIA Call Control Procedures).......................................................................... 6-11 Figure 6-11 Simple Call Flow, Gateway Initiated Call Disconnect Example (ETSI Call Control Procedure) (Part 2 of 2)...................................................... 6-12 Figure 6-12. Simple Call Flow, Three-Party Calling Example (TIA Call Control Procedures) ................................................................................................ 6-13 Figure 6-13. Simple Call Flow, Call-Waiting Example (TIA Call Control Procedures) ................................................................................................ 6-14 Figure 6-14. Call Processing During Soft Handoff.................................................... 6-15 Figure 6-15. Call Processing During Sequential Soft Handoff................................ 6-16 Figure 6-16 Call Processing During Sequential Soft Handoff (Part 2 of 2) ............ 6-17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 vi Description of the Globalstar System GS-TR-94-0001 Revision E Tables Table 1-1 Teleservices....................................................................................................1-1 Table 1-2 Basic Bearer Services ..................................................................................1-2 Table 1-3 IS-53 Call Number Presentation...............................................................1-2 Table 1-4 IS-53 Call Forwarding .................................................................................1-3 Table 1-5 IS-53 Call Delivery .......................................................................................1-4 Table 1-6 Short Message Services ...............................................................................1-4 Table 1-7 Miscellaneous Services ................................................................................1-5 Table 1-8 Future IS-41 C Services ..............................................................................1-6 Table 1-9 Bearer Service - Full Duplex Asynchronous Data.................................1-8 Table 1-10 Bearer Service - Full Duplex Synchronous Data.................................1-9 Table 1-11 Bearer Service - PAD Asynchronous Data............................................1-9 Table 1-12 Bearer Service - Packet Synchronous.................................................1-10 Table 1-13 Teleservices Speech..................................................................................1-10 Table 1-14 Teleservices - Short Message Service...................................................1-10 Table 1-15 Teleservices - Facsimile Transmission................................................1-12 Table 1-16 Supplementary Services - Line Identification....................................1-12 Table 1-17 Supplementary Services - Call Forwarding.......................................1-13 Table 1-18 Supplementary Services - Call Waiting & Call Hold........................1-13 Table 1-19 Supplementary Services - Closed User Group....................................1-13 Table 1-20 Supplementary Services - Advice of Charge.......................................1-13 Table 1-21 Supplementary Services - Call Barring...............................................1-14 Table 1-22 Supplementary Services - Multiparty Services..................................1-14 Table 1-23 External Network - Value Added Services..........................................1-17 Table 2-1 Production User Terminals ........................................................................2-3 Table 3-1 Satellite C-Band to S-Band ........................................................................3-5 Table 3-2 Satellite L-Band to C-Band ........................................................................3-5 Table 3-3 Satellite Telemetry & Command Frequencies .......................................3-6 Table 3-4 Worst Case Doppler......................................................................................3-6 Table 3-5 Forward Link C-Band - Case 1 - Detailed Budget ...............................3-14 Table 3-6 Forward Link S-Band - Case 1 - Detailed Budget................................3-15 Table 3-7 Forward Link - Case 2 - Link Blockage..................................................3-16 vii 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Description of the Globalstar System GS-TR-94-0001 Revision E Table 3-8 Forward Link - Case 3 - Rare Two Link Fade.......................................3-16 Table 3-9 Return Link L-Band - Case 1 - Detailed Budget..................................3-17 Table 3-10 Return Link C-Band - Case 1 - Detailed Budget ...............................3-18 Table 3-11 Return Link - Case 2 - Link Blockage..................................................3-18 Table 3-12 Return Link - Case 3 - Rare Two Link Fade.......................................3-19 Table 4-1 Vocoder and Channel Rates ....................................................................4-14 1 2 3 4 5 6 7 viii Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 3 4 5 6 7 8 ix Description of the Globalstar System GS-TR-94-0001 Revision E 1. SERVICES OFFERED 1.1 Service Types Four types of communications services are supported by Globalstar depending on the environment in which they operate (1) IS-41 Services, (2) GSM Services, (3) Globalstar Specific Services and (4) Network Value Added Services. 1.2 IS-41 Services The following IS-41-based services are supported directly by the gateway. The IS 41 switch is in the Gateway. The IS-41 C teleservices are listed in Table 1-1. Service Option Telephony (circuit speech) Emergency Services (911) Table 1-1 Teleservices Description Variable rate vocoded speech. Comparable or better than IS-

96A. Globalstar emergency calls are routed to a single LAC directory number for further processing. Although the Gateway retrieves position location data of the calling subscriber, position data is not provided to the Emergency Service Center. Automatic Facsimile Group III Normal Group III FAX Digital PC Only - (Future) Lawful Intercept DTMF Support GS complies with the laws in the areas where they operate. In the U.S.A, this is call content and call associated data per DOJ J-STD-25 with minor exceptions. Dual Tone Multi Frequency. Used for voice Message Retrieval etc. Signal via GAI. Generated in GW or UT. The IS-41 switch within the Gateway does not perform routing to sub-tier emergency numbers. The Gateway can be configured to support multiple Location Area Codes (LAC). A different emergency number can be assigned to each LAC. 1-1 1 2 3 4 5 6 7 8 9 10 11 12 13 Description of the Globalstar System GS-TR-94-0001 Revision E Basic bearer services are listed in Table 1-2. Table 1-2 Basic Bearer Services Service Option Description 2.4 Kb/s: DCA, (ADS) 4.8 Kb/s: DCA, (ADS) 9.6 Kb/s: DCA, (ADS)

(Future)

(Future)

(Future) Data Requires Flow Control: The Globalstar Air Interface (GAI) and the Gateway support packet data. Because there is overhead in the GAI, external flow control is required to offer a 9.6 Kb/s service. End to end peak throughput of the Globalstar link will be on the order of 7.2 Kb/s. The initial offering (near future 1.5 D2) of Async Data will be Mobile Originated (MO) only. Mobile Terminated (MT) will require modifications to the HLR (future). Connecting the call will require about 5 seconds. This is then followed with a variable time to train the modem. IS-53 Supplementary Services supported by the Gateway are listed in Table 1-3. Table 1-3 IS-53 Call Number Presentation IS-53 Supplementary Services - Call Number Presentation Service Option Description Calling number identification presentation

(CNIP) CNIP provides the number identification of the calling party to the called subscriber. One or two numbers may be presented to identify the calling party. Calling number identification restriction (CNIR) CNIR restricts presentation of that subscribers calling number identification (CNI) to the called party. 1 2 3 4 5 6 7 8 9 10 11 12 1-2 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 Table 1-4 lists some of the IS-53 call forwarding features. Table 1-4 IS-53 Call Forwarding IS-53 Supplementary Services - Call Forwarding Service Option Description Call forwarding unconditional (CFU) Call forwarding default (CFD) Call Forwarding - Busy (CFB) Call Forwarding - No Answer (CFNA) CFU permits a called subscriber to send incoming calls addressed to the called subscribers directory number to another directory number or to the called subscribers designated voice mail box. If this feature is activated, calls are forwarded regardless of the condition of the termination. CFD permits a called subscriber to send incoming calls addressed to the called subscribers directory number to the subscribers voice mail box or to another directory number when the subscriber is engaged in a call, does not respond to paging, does not answer the call within a specified period after being alerted or is otherwise inaccessible. CFB permits a called subscriber to have the system send incoming calls addressed to the called subscribers directory number to another directory number or to the called subscribers designated voice mail box when the subscriber is engaged in a call or service. CFNA permits a called subscriber to have the system send incoming calls addressed to the called subscribers directory number to another directory number or to the called subscribers designated voice mail box when the subscriber fails to answer or is otherwise inaccessible. CFNA does not apply when the subscriber is considered to be busy. 1-3 Description of the Globalstar System GS-TR-94-0001 Revision E Table 1-5 lists some of the IS-53 Call Delivery features. Table 1-5 IS-53 Call Delivery IS-53 Supplementary Services - Call Delivery Features Service Option Description 3-way calling (3WC) Do not disturb (DND) Call transfer (CT) Call delivery (CD) Call waiting (CW) 3WC provide the subscriber the capability of adding a third party to an established two-party call, so that all three parties may communicate in a three-way call. Calling party initiated. DND prevents a called subscriber from receiving calls. When this feature is active, no incoming calls will be offered to the subscriber. DND also blocks other alerting, such as CFU reminder alerting and message waiting notification alerting. DND also makes the subscriber inaccessible for call delivery. DND does not impact a subscribers ability to originate calls. CT enables the subscriber to transfer a call that is already in process to a third party. The call to be transferred may be an incoming or outgoing call. While CT is invoked, CT impacts the subscribers ability to receive calls. After CT is finished or when CT is not invoked, CT does not impact a subscribers ability to originate calls or to receive calls. CD permits a subscriber to receive calls to his or her directory number while roaming. CW provides notification to a controlling subscriber of an incoming call while the subscriber is in the 2-way state. Subsequently, the controlling subscriber can either answer or ignore the incoming call. If the controlling subscriber answers the second call, he or she may alternate between the two calls. Lawful Intercept Implications: The IS-53 Call Delivery services are coded and operational in the present software release. When Release 1.5 D-3, with Lawful Intercept is released (Future), many of the IS-53 Call Delivery features will have to be disabled. Short Message Services are supported as listed in Table 1-6. Table 1-6 Short Message Services Service Option Description Short message deliverypoint-to-point (SMD-

PP) SMD-PP provides delivery of a short message. The SMD-PP service attempts to deliver a message to a Globalstar UT whenever the UT is registered even when the UT is engaged in a voice or data call. 1-4 1 2 3 4 5 6 7 8 Description of the Globalstar System GS-TR-94-0001 Revision E The IS-41 SMS will be compliant with IS-637. A few examples will clarify how MT SMS is envisioned (future) to operate:

1. If a short message comes into the gateway from the SMSC that is less than about 65 characters (45 characters of payload) it will be routed to the UT over the paging channel. 2. If an SMS message arrives while the traffic channel is set up, it will be routed over the already established traffic channel. This can be a message of up to about 246 characters (200 characters of payload). 3. If a long message arrives and a traffic channel is not set up, it will be set up and the SMS message will be sent. The Gateway will support about 5,000 Busy Hour Short Message Access (BHSMA). Lawful Intercept: The SMS LI will be supported as Call Associated Data (CAD) in future software release 1.5 D3. There are several other items that may be considered services listed in Table 1-7. These are primarily associated with validating the caller and with providing privacy. Table 1-7 Miscellaneous Services Service Option Description Authentication Voice Privacy (VP)

(Function provided in different manner) Data Privacy

(Function provided in different manner) Signaling Privacy

(Function provided in different manner) Authentication provides a secure way to identify authorized subscribers in order to prevent fraudulent use of the network resources. VP provides a degree of privacy for the subscriber over the Globalstar Air Interface. When VP is invoked, the speech or traffic channel used is encrypted. Over the Air Encryption is supported. Private keys between SM and Authentication Center. Over the Air Encryption is supported. Private keys between SM and Authentication Center. Security Module (SM) in the context above should not be confused with the GSM Subscriber Identification Module (SIM). It is a security module function. The over the air encryption of traffic is an algorithm similar to the GSM A5 algorithm. The traffic channel is encrypted. Signaling to set up the call is not encrypted. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 1-5 Description of the Globalstar System GS-TR-94-0001 Revision E Table 1-8 lists services that may be offered in the future. They are not presently within the scope of work. The initial offering will include 3-way calling. If Conference Calling (CC) is adopted later, the older service could be dropped or continued. Table 1-8 Future IS-41 C Services Future IS-41 C Services Acronym Service Description CPT CMT SPINA CC FA MWN MAH PCA PL VMR VP SP PACA RFC SCA Cellular Paging Teleservice Cellular Messaging Teleservice Subscriber PIN Access A PIN is required. Network based lockout feature. Conference Calling Flexible Alerting Provides ability to connect more than 3 parties. A call to a pilot number to alert several numbers simultaneously. Message Waiting Notification Informs subscribers a voice message is waiting. Mobile Access Hunting Password Call Acceptance Preferred Language Causes a call to a pilot directory to search a list of enrolled subscribers. Terminates with the first available subscriber in the list. This is a call-screening feature that limits incoming calls to subscribers able to provide a password. Allows the subscriber to specify language for network services. This includes help lines, announcements, message waiting notifications and SMS. Voice Message Retrieval Allows subscriber to retrieve voice messages. Voice Privacy Signaling Privacy Priority Access and Channel Assignment Remote Feature Control Selective Call Acceptance Provides a degree of voice privacy. Provides a degree of signaling privacy. Allows subscriber to move to top of queued list. Available in levels, permanent or on demand. Called numbers such as 911 may be given priority at the Service Provider option. Calls to a special RFC directory number validated by a PIN can be used to activate features. DTMF digits are required. Allows only calls whose Calling Party Numbers are in a screening list. SPINI Subscriber PIN Intercept A PIN is required. User Terminal based lockout. These are mentioned here so that we recognize that these may be offered eventuality and Globalstar will do nothing in the design to preclude their incorporation at a later date. Globalstar has some of the functions with some interpretation specifically:

1 2 3 4 5 6 7 1-6 Description of the Globalstar System GS-TR-94-0001 Revision E 1. MWN: Message Waiting Notification is mechanized via the SMS. 2. VMR: Facilities are available to access voice messages although not precisely as specified in IS-41. 3. VP: The Traffic Channel is encrypted. 4. SP: Any signaling within the traffic channel is encrypted. 5. PACA: The User Terminal, the GAI, and the Gateway support 10 priority levels. These may be used to control which call gets resources. Calls that are setup are not broken down to support PACA functions within Globalstar. 1 2 3 4 5 6 7 8 1-7 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 1.3 GSM Services The Globalstar Gateway can incorporate a GSM switch or the Gateway can be utilized with an external GSM switch. In either case the Gateway proper is connected to the GSM switch by the GSM A1 interface. This section lists the bearer services and teleservices supported by the Alcatel GSM MSC Table 1-9 Bearer Service - Full Duplex Asynchronous Data Bearer Service - Full Duplex Asynchronous Data Acronym Service Description BS 21 BS 22 BS 23 BS 24 BS 25 BS 26 300 bps Asynchronous Full Duplex Data Circuit - Asynchronous 1200 bps Asynchronous Full Duplex Data Circuit - Asynchronous 1200/75 bps Asynchronous Not Supported 2400 bps Asynchronous Full Duplex Data Circuit - Asynchronous 4800 bps Asynchronous Full Duplex Data Circuit - Asynchronous 9600 bps Asynchronous Full Duplex Data Circuit - Asynchronous The Information Transfer may be 3.1 kHz (External to Public Land Mobil Network (PLMN)). The Gateway will not support an Unrestriced Digital Interface (UDI). The connection is digital within the PLMN. The service can be transparent (T) or Non Transparent (NT). Transparent service is characterized by constant throughput, constant transit delay and variable error rate. Non-Transparent service is characterized by improved error rate with variable transit delay and throughput. The Globalstar Air Interface is a packet system. The top rate for a single channel is 9.6 kb/s. This includes some overhead. This means Globalstar will not support a true 9.6 kb/s throughput service. The best estimate is the actual throughput will be on the order of 7.2 kb/s. The difference is required for overhead. The data connections on each end can operate asynchronously at 9.6 kb/s so that can be the apparent peak service rate. Expansion buffers will be required to allow the peak rate of 9.6 kb/s with an average around 7.2 kb/s. Services Requiring Constant Transit Delay: The Globalstar Air Interface is a packet data system that exhibits a high error rate. While some of the errors can be corrected by Forward Error Correcting Codes, repeat transmissions will be required. This means:

1. Through put time delay is variable. 2. Cannot support true synchronous operation There are ways, with flow control, to provide these as apparent services by providing smart equipment at the ends of each link. 1-8 1 2 3 4 5 6 7 8 9 10 11 12 Description of the Globalstar System GS-TR-94-0001 Revision E DTAP Based Services: Any services that use the DTAP messages can be supported as long as the switch and the User Terminal support the service. DTAP messages are passed transparently thorough the gateway, the air interface, and the Globalstar User Terminal. GSM Data Services: GSM Asynchronous Services are targeted for Release 1.5 D4 (future). This is required for before Synchronous Services could be considered even with elastic buffer equipment in the link termination equipment. Table 1-10 Bearer Service - Full Duplex Synchronous Data Bearer Service - Full Duplex Synchronous Data Service Typo Acronym Service Description BS 31 BS 32 BS 33 BS 34 1200 bps Synchronous 2400 bps Synchronous 4800 bps Synchronous 9600 bps Synchronous Data Circuit, Duplex Synchronous Data Circuit, Duplex Synchronous Data Circuit, Duplex Synchronous Data Circuit, Duplex Synchronous (not supported) The Information Transfer may be Unrestricted Digital (UDI) or 3.1 kHz (External to PLMN). The connection is digital within the PLMN. Operating mode can be transparent (T) or Non Transparent (NT). Transparent service is characterized by constant throughput, constant transit delay and variable error rate. Non-Transparent service is characterized by improved error rate with variable transit delay and throughput. Synchronous operation can be simulated in Globalstar by external equipment. Throughput is at a lower rate. Technically this service could be offered. The Service Provider must provide some end to end adaptation equipment on each end to make the link look synchronous. Throughput is limited by the flow control. Specifically, end to end encryption devices can be used that normally operate with synchronous links. Table 1-11 Bearer Service - PAD Asynchronous Data Bearer Service - PAD Asynchronous Data Service Type Acronym Service Description BS 41 BS 42 BS 43 BS 44 BS 45 BS 46 300 bps Asynchronous Data Circuit, Duplex Asynchronous 1200 bps Asynchronous Data Circuit, Duplex Asynchronous 1200/75 bps Asynchronous Data Circuit, Duplex Asynchronous 2400 bps Asynchronous Data Circuit, Duplex Asynchronous 4800 bps Asynchronous Data Circuit, Duplex Asynchronous 9600 bps Asynchronous Data Circuit, Duplex Asynchronous PAD: provides an asynchronous connection to a Packet Assembler/Disassembler. This service is available only for mobile originated calls. 1-9 Description of the Globalstar System GS-TR-94-0001 Revision E Table 1-12 Bearer Service - Packet Synchronous Bearer Service - Packet Synchronous Acronym Service Description BS 51 BS 52 BS 52 2400 bps Synchronous 4800 bps Synchronous 9600 bps Synchronous Data Circuit, Duplex Synchronous Data Circuit, Duplex Synchronous Data Circuit, Duplex Synchronous Provides a synchronous connection to a packet network. Can be simulated in Globalstar by external equipment. Throughput is at a lower rate. Globalstar is a packet system. It does not directly support synchronous services. Devices on each end can operate so that the connection is apparent synchronous. True synchronous operation is not feasible. Technically this service could be offered. The Service Provider must provide some end to end adaptation equipment on each end to make the link look synchronous. Throughput is limited by the flow control. Specifically, end to end encryption devices can be used that normally operate with synchronous links. Acronym Service TS 11 TS 12 Telephone Service Emergency Calls Table 1-13 Teleservices Speech Teleservices - Speech Description This is the basic voice telephone service. Emergency Calls do not require registration. They can be on IMSI or IMEI. The Gateway requires an IMSI for all calls. This means emergency calls too. The User Terminal could be designed to provide a pseudo-IMSI so that at UT could be used without the SIM. Table 1-14 Teleservices - Short Message Service Teleservices - Short Message Service Acronym Service Description MT/PP TS 21 MO/PP TS 22 Short Message Mobile Terminated Point-to-Point Permits the SMS service center to send a message to any subscriber that is less than 160 ASCII characters (future) Short Message Mobile Originated Point-to-Point Permits any subscriber to send a message to any other subscriber that is less than 160 ASCII characters. The SMS service center acts as a store and forward node (future). 1 2 3 4 5 6 7 8 9 10 11 12 13 1-10 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 An IS-41 Mobile Originated only variant will be offered in the near future. The Alcatel switch will require modification to support Mobile Originated SMS. Although the switch supports SMS Mobile Terminated broadcast, Globalstar does not support this service. 1-11 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 Table 1-15 Teleservices - Facsimile Transmission Teleservices - Facsimile Transmission (Not Supported by Globalstar) Acronym Service Description TS 61 TS 62 Alternate Speech and Facsimile Group 3 (T or NT) Speech and data can be alternated during the call. Automatic Facsimile Group 3 (T or NT) Dedicated service. Operating mode can be transparent (T) or Non Transparent (NT). Transparent service is characterized by constant throughput, constant transit delay and variable error rate. Non-Transparent service is characterized by improved error rate with variable transit delay and throughput. Although the Alcatel switch supports these modes, they are not available over Globalstar. The air interface operates NT. Timing could be adjusted so digital FAX machines will not timeout. Table 1-16 Supplementary Services - Line Identification Supplementary Services - Line Identification - GSM 02.81 (Not Supported by Globalstar) Acronym Service Description CLIP CLIR COLP COLR Calling Line Identification Presentation Calling Line Identification Restriction Permits the called party to receive the line identity of the calling party. Permits the calling party to block his line identity to the called party. Connected Line Identification Presentation The calling party can receive the line identity of the connected party. Connected Line Identification Restriction Permits the connected party to block his line identity to the calling party. 6 COLP and COLR are mandatory. 1-12 Description of the Globalstar System GS-TR-94-0001 Revision E Table 1-17 Supplementary Services - Call Forwarding Supplementary Services - Call Forwarding (CF) GSM 02.82 Acronym Service Description CFU CFB Call Forwarding Unconditional Incoming calls are forwarded to another number. Call Forwarding - Busy Line is busy, calls are sent to another number. CFNRy Call Forwarding on No Reply When there is no reply within a specified period of time, calls are sent to another number. CFNRc Call Forwarding on Mobile Subscriber Not Reachable When the called party is not reachable, calls are forwarded to another number. Table 1-18 Supplementary Services - Call Waiting & Call Hold Supplementary Services - Call Waiting (CW) and Call Holding (HOLD) GSM 02.83 (Not Supported by G*) Acronym Service CW HOLD Call Waiting Call Hold Description Notify the called party that a call is waiting. Place an active call on hold. Table 1-19 Supplementary Services - Closed User Group Supplementary Services - Closed User Group GSM 02.85 (Not Supported by Globalstar) Acronym Service Description CUG Closed User Group Communications permitted only with group. The switch supports a MS belonging to up to 10 CUGs. Table 1-20 Supplementary Services - Advice of Charge Supplementary Services - Advice of Charge GSM 02.86 (Not Supported by Globalstar) Acronym Service Description AOC AOC Advice of Charge Information Provides and estimate of the size of the bill. Advice of Charge Charging Provides an accurate charge to support immediate billing

(e.g. Taxi phone). The Alcatel GSM-MSC supports Warm billing. Partial records can also be obtained for long calls. The SP should consider carefully before offering any service that requires Hot Billing. 1 2 3 4 5 6 7 1-13 1 2 3 Description of the Globalstar System GS-TR-94-0001 Revision E Table 1-21 Supplementary Services - Call Barring Supplementary Services - Call Barring (CB) GSM 02.88 Acronym Service Description BAOC BOIC BOIC-exHC Barring of All Outgoing Calls There are no outgoing calls except emergency calls. Barring of Outgoing International Calls Bars international calls from the PLMN in which the subscriber is presently located. Barring of Outgoing International Calls except those directed to the Home PLMN Country Outgoing calls are barred except local calls and to the home PLMN country. BAIC Barring of All Incoming Calls No incoming calls are permitted. GSM 02.88 BIC ROAM Bar Incoming Calls - Roaming No incoming calls are permitted when roaming outside the home PLMN. Table 1-22 Supplementary Services - Multiparty Services Supplementary Services - Multiparty Services (Not Supported by Globalstar) Acronym Service Description MPTY Multi Party Service Establish and delete multiple parties in any order. 4 Conference Calling or Multi-Party Service is mandatory. 1-14 Description of the Globalstar System GS-TR-94-0001 Revision E 1.4 Globalstar Specific Services and Quality The following services and statements result from the Globalstar implementation and apply to both GSM and IS-41. Globalstar Specific Services Position Location (high resolution), 300 m (Future) Position Location (low resolution), 10 km Global Roaming Terminal Services CDG Sleep Mode Internet Services: Internet services have been tested and operate reliably. In order to offer the service, the gateway must supply some modem equipment and must interface at the Selector Bank Subsystem (SBS). Offering the packet service implies Internet, e-mail, stock quotes and a host of attractive services. . The billing is quantized to 0.1 second intervals. Byte based billing is not supported. The Gateway support will be in Release 1.5 D2, which should be in the near future Slotted Mode: An IS-41 slotted mode operation will be available is software release 1.5 D2 scheduled for the near future. This will increase battery receive battery life on the order of 2:1. Longer slot delays cause unacceptable latency and result in very slight improvements. This IS-41 service is mechanized by storing the slots in the VLR located in the gateway. It would be necessary to access the GSM VLR to offer slotted mode as a GSM feature. Slotted mode is turned off when the handset is placed in a car kit. Throughput Rates: The data rate of the air interface plus overhead for the radio link protocol, etc. limits the effective data rate to approximately 7.2 Kb/s (if enough power has been allocated and there is no blockage of view). It is possible to interface to a higher rate service at the network interface (e.g., V.32), but the actual data rate is limited. Short Message Service: The gateway will support interfaces to GSM and IS-41 short message service centers for SMS. Voice Quality - Voice service is based on a Code Excited Linear Prediction (CELP) variable rate vocoder. The voice processing will incorporate a procedure to aid in cancellation of background noise. The voice quality will meet or exceed the voice quality provided by IS-96A, the terrestrial CDMA standard. This superior voice quality can be offered at the lower data rates in large part due to the adaptable rate vocoders used in Globalstar. The voice quality cited is based on a Ricean channel model 1-15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Description of the Globalstar System GS-TR-94-0001 Revision E that requires a forward link Eb/No and return link Eb/No as defined in the link budget. A soft degradation is incorporated into the design. In marginal areas where the User Terminal cannot generate sufficient power to close the link, the peak data rate is reduced to 4.8 Kb/s or 2.4 Kb/s. This will provide intelligible voice communications in areas that otherwise could not be served. The Vocoders will incorporate echo cancellation, which can be disabled if this function is provided by the network. Data Quality - Data services are provided up to 7.2 Kb/s. The a Bit Error Rate contributed by Globalstar is less than 1 X 10 -6. Higher terminal rates (e.g. 9.6 Kb/s) can be processed if the equipment incorporates elastic buffers to accommodate the required flow control. Encryption: Over the air signaling (in band), voice and data encryption is offered. Registration - The Gateway is capable of providing a position location function on the User Terminal with which it is communicating. The accuracy is within 10 km for registration. This is used to determine assignment of User Terminals to Gateways. Location Service: Globalstar can locate the position of a User Terminal and provide the location as a service in the future. Accuracy of the position location service is a function of several variables including:

a. Number of Satellites in View. b. Position Accuracy of the Satellites c. Geometry of the User Terminals, Satellites and Gateways. d. The length of time that the User Terminal is connected to the Gateway. The architecture will support better precision once the gateway locations are known with sufficient accuracy and the topographical maps are correctly registered. With this a likely service, this document includes some description of the position location methods. Location Privacy - The location of a user is protected. Only duly constituted authorities will have access to these data unless approved by the owner of the User Terminal. Tracking Service - The Gateway is able to use sequential position locations to determine and maintain tracking services for mobile users. Offering these services is dependent upon the legality within the regions supported by the Service Providers. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 1-16 Description of the Globalstar System GS-TR-94-0001 Revision E 1.5 External Network Supported Services The Gateway design will incorporate nothing to block network operator value added service such as those listed in Table 1-23. Whether the service can be offered depends upon the details of how the service offering is to be interfaced with the Gateway. This assumes of course that the Globalstar Air Interface (GAI) and the User Terminal (UT) will support the value-added service. Table 1-23 External Network - Value Added Services External Network - Value Added Services Acronym Service Description Automatic IMSI replacement Old SIM remains valid until first use of new SIM. Operator Determined Barring CAMEL Phase I Core-INAP Warm/Hot Billing Single Numbering Operator Services GSM Mobile Intelligent network Billing can be to the OMC in less than 5 minutes. One number follows the subscriber. Assistance or Help Desk. Operator Defined Barring (ODB) Network operator can bar even if UT selects. Mail Boxes Store and forward Voice, FAX or Digital Messages. Dial in information. Can be Voice, FAX and/or data. Alarm and Wake up calls. Alert under defined conditions. Paging Services Credit Control Page a Subscriber Network Operator Managed. 1 2 3 4 5 6 7 1-17 Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 1-18 1 2 3 4 5 6 Description of the Globalstar System GS-TR-94-0001 Revision E 2. SYSTEM SEGMENT DESCRIPTIONS 2.1 Globalstar System The Globalstar system consists of a Space Segment, a User Segment, a Ground Segment, and a Terrestrial Network as shown in Figure 2-1. S a t e lli t e S a t e lli t e S a t e lli t e S p a c e S e g m e n t U s e r S e g m e n t S - B a n d D o w n L in k L - B a nd Up L in k P o r t a b le M o b il e F ix e d Gr o u nd S e g m e n t T e r r e st r ia l N e t w o r k LAN C -B a n d U p L i n k C -B an d D o w n L i n k GBO GO C C S O C C GDN Interface TCU G at e w a y G lo b a ls t a r D a t a N e t w o r k G S M -M SC P T T In t e r n a t io n a l C a r r ie r L o n g D ist a n c e C a r r ie r W i r el in e T e l co P S T N / P LM N Figure 2-1 Globalstar System Integrates with Terrestrial Network 2-1 CDA S P C C C e l l u l a r C a r r i e r P r i v a t e N e t w o r k 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Description of the Globalstar System GS-TR-94-0001 Revision E The Globalstar system provides communications from any point on the earth surface to any other point on the earth surface, exclusive of the Polar Regions as shown in Figure 2-2. Figure 2-2 Globalstar Constellation Serves Temperate Areas The satellite orbits are optimized to provide highest link availability in the area between 70 degrees south latitude and 70 degrees north latitude. Service is feasible in higher latitudes with decreased link availability. The Globalstar space segment consists of 48 satellites in 1410 km Low Earth Orbits. The low orbits permit low power hand sets similar to cellular phones. These satellites are distributed in 8 orbital planes with 6 equally spaced satellites per orbital plane. Satellites complete an orbit every 114 minutes. User Terminals in a particular location on the surface of the earth are illuminated by a 16-beam satellite antenna as it passes over the earth. User Terminals can be served by a satellite 10 to 15 minutes out of each orbit. A smooth transfer process between beams within a satellite and between satellites provides unbroken communications for the users. The orbital planes are inclined at 52 degrees. Coverage is maximized in the temperate areas with at least two satellites in view, providing path diversity over most of the area. There is some small sacrifice in multiple satellite coverage at the equator and at latitudes above 60 degrees. The Gateways to the terrestrial network are illuminated by an earth coverage beam. The Gateway connects the User Terminal to the terrestrial network via the Gateway. The terrestrial network is not a part of Globalstar. 2-2 Description of the Globalstar System GS-TR-94-0001 Revision E 2.2 User Terminal The User Terminals come in several varieties. There are hand held units, mobile units and fixed station units. The available types of User Terminals are listed in Table 2-1 Table 2-1 Production User Terminals Fixed Terminal Hand Held and Mobile Globalstar Only Dual Mode Globalstar & GSM Tri Mode Globalstar & Terrestrial CDMA & AMPS 2.2.1 Hand Held and Mobile Units Typical hand held units are shown in Figure 2-3. Qualcomm Tri-mode AMPS CDMA Globalstar Ericsson Dual-Mode GSM Globalstar Telit Dual-Mode GSM Globalstar Figure 2-3 Typical Hand Held User Terminal 2-3 1 2 3 4 5 6 7 Description of the Globalstar System GS-TR-94-0001 Revision E Globalstar Mode: Hand held User Terminals look like a standard cellular telephone. These are multiple mode handsets that operate with the local cellular system or Globalstar. The radiating element of the antenna is positioned above the head of the user. The antenna is positioned vertically to effectively utilize the symmetrical radiation pattern of the hand held antenna. The area next to the head is not used for radiation. This meets the safety requirements. Cellular Mode: When operating as a cellular mode handset, normal cellular operation can be expected. Cellular uses a separate and smaller antenna as is the custom with cell phones. Mobile - The mobile units consist of a hand held unit inserted in an adapter in the vehicle. The Mobile units typically have a higher gain antenna, a lower noise receiver and a higher RF power output. This is part of the adapter kit. The improved transmitter and receiver are mounted in the base of the antenna. The car kit that goes with a mobile typically includes:

1. Hands Free Speaker and Microphone 2. Outdoor Unit with a superior antenna 3. Operation with the Vehicle battery 1 2 3 4 5 6 7 8 9 10 11 12 13 14 2-4 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 Block Diagram - Figure 2-4 is a simplified block diagram of the Globalstar portion of a User Terminal, which includes Globalstar/CDMA/AMPS. Diagnostic Monitor 115.2K Serial I/O 49.152 MHz Clock Rx Antenna LNA S Band Downconverter Rx IF Intel 386EX:

2 ch DMA 2 ch Serial 3 Timer/ctrs Watchdog Refresh ctl Chip Sel unit Address TC554161 256K X 16 SRAM 16L Data Ringer 28F016 1Meg X 16 Flash LCD Display 1 4 7

2 5 8 0 3 6 9

TCXO &

Synths Ref Clk Tx Antenna PA L Band Upconverter Tx IF RF Assembly Irq BBII ASIC 10L Add 8 bit I&Q ChipX8 GUM ASIC:

rake receiver/

deinterlvr/dec xmit enc/interleave dig FM , fart Sync & Clk RS-232 translator Data Port 38.4K Serial I/O SM Socket TLV320AV Codec ADSP-2185L Vocoder 16.6 MHz Resonator Fr_Ref 8L Data 7.2V 1.4AHr Power Converter 5.0V PA 3.6Vaa 3.3Vdd 3 4 5 6 7 8 9 Figure 2-4 Globalstar User Terminal Block Diagram Since there is no hand off between the local cellular system and Globalstar, if the user crosses a service boundary between the local cellular system and Globalstar, the call could be dropped and must be placed again. The indicators tell the operator that the mode has changed. The system will not thrash in a boundary area. The user can select the preferred mode. If cellular is preferred and coverage is not available the UT will drop the call. The call can be placed in Globalstar mode. This call will continue until the phone is in an idle state. The reverse is also true. 2-5 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 Function Performed : The start up functions of a User Terminal are programmable. As an example, when a dual-mode User Terminal first powers up it may attempt to log into the local cellular system. This addresses a scenario where the cellular system gets first priority to provide the service. If this fails the User Terminal then attempts to log onto the Globalstar system. Figure 2-5 illustrates a typical startup scenario within Globalstar. Power-up User Terminal Initialization State User Terminal has fully acquired system timing User Terminal Idle State Receives a Paging Channel message requiring an acknowledgment or response; originates a call or performs registration. Receives an acknowledgment to an Access Channel transmission other than an Origination Message or a Page Response Message System Access State Ends use of the Traffic Channel Note: Not all state transitions are shown. Directed to a Traffic Channel User Terminal Control on the Traffic Channel State 6 7 8 9 Figure 2-5 User Terminal Startup Scenario within Globalstar The User Terminal looks for the best satellite pilot signal. When this is found it then switches to the sync channel and obtains the satellite database and other information. This database facilitates rapid 2-6 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Description of the Globalstar System GS-TR-94-0001 Revision E acquisition of the pilot for any future calls. To place a call the user dials the number and presses

"SEND". The User Terminal contacts the Gateway via the access channel. The Gateway and the User Terminal then work together to connect the call and support communications. Since the satellites are moving, the user is continuously being illuminated by different satellite beams or even different satellites. Diversity combining within the receivers supports a process of transferring traffic that is completely transparent to the user. The diversity combining process also provides better call reliability. The hand off process is accomplished without interruption to the call in process. If the user moves into an area that shadows or blocks access to one satellite, the space diversity link through a satellite that is not blocked maintains uninterrupted user communication 2.2.2 Fixed Terminals Fixed station terminals are normally Globalstar only. The fixed User Terminals have a performance equivalent to the mobile terminal except that the antenna gain and transmitter power may be even higher. Fixed terminals do not require path diversity to combat fading and blockage. Fixed Terminals must support seamless beam to beam and satellite to satellite hand of Gateway Gateway PSTN Figure 2-6 Typical Fixed Terminal Application The fixed terminals can operate with a fixed phone, a payphone or other equipment. 2-7 1 2 3 4 5 6 7 8 9 10 11 Description of the Globalstar System GS-TR-94-0001 Revision E 2.3 Gateway The Gateways are geographically distributed by the service providers to serve their customer base. Figure 2-7 is a typical Gateway Figure 2-7 Typical Gateway Installation Gateways are designed for unmanned operation. A gateway consists of up to four 5.5-meter antennas as shown on the left and electronics equipment installed in a building or shelter as show on the lower right. In addition to the equipment racks, the facility supplied by the Service Provider includes prime power, an Uninterrupted Power System (UPS), as well as any maintenance or office facilities. The antenna layout is flexible. The major constraint is to place the antennas so that they do not block visibility of the satellite constellation. Safety considerations for the operating area must also be observed. 2-8 Description of the Globalstar System GS-TR-94-0001 Revision E 1 Figure 2-8 is a simplified block diagram of a typical Gateway. SOCC GOCC GDN GDN Router DGlobalstar SPCC 1 47 8

0 2 5 3 6 9#

DIGITAL BY ROPI ABC GW Links E1 or T1 BCN MSSL Ethernet IFL TCU

(Telemetry & Command Unit) OPI GMS

(Gateway Management System) GSS

(Gateway Switching System) SPCC Router GM CDA TCU TCU TCU TCU T C U P a n e l FL SSPA U p C o n v e r t e r FL Cabinet FL Shelf 5/polarize/ant

(40) RHCP LHCP GCU SS C a r d s U p c o n v e r t e r M o d u l a t o r C a r d s GPS Rcvr TFU 12 1 11 10 9 8 7 56 2 3 4 GWRDB CCP VME Cage V M E Backplane VLR SS7 SS7 Server VME Cage BSCI SS7 SSA T1 P a t c h P a n e l NIS P a t c h P a n e l CSU P a t c h P a n e l 2 1 T1/E1 Trunks IS-41 HLR GSM HLR OMC VLR SS7 GSM MSC E 1 Trunks 3 PSTN Trunk Set Combinations

(most likely):

IS-41 territory:

GSM territory:

1 2 2 3 CIS

(DISCO) Router SBS SBS Shelf 1/96 calls C a r d s

1 2

) S e l e c t o r I C a r d n t e r f a c e GWC VME Cage GCS

(Gateway CDMA System) T1 VIP Globalstar D O FF O N 2 1 4 3 6 7 5

8 9 0 DIGITAL BY

RL LNA C o n v e r t e r D o w n RHCP LHCP TFU TFU Cabinet Cabinet

(2)

(2) S S p p l l i i t t t t e e r r s s Antennas

(up to 4) GRS

(Gateway RF System) GTS RL Receive Cabinets

(up to 13) C a r d s R e c e i v e r C a r d C o n t r o l l e r Digital Cabinets

(up to 13) C o m m o n C a r d D e m o d C a r d s 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Figure 2-8 Gateway Simplified Block Diagram Appearance : The Gateway consists of up to four identical parabolic antennas that are at least 5.5 meters in diameter. The antenna structure contains drive mechanisms for positioning the antenna, low noise receivers and high power transmitters. The antenna structure may be enclosed in a Radome to provide protection from the environment. The antennas connect to a building that houses the electronics equipment. The Code Division Multiple Access (CDMA) equipment, PSTN interface equipment that interfaces with the terrestrial telephone network, and computer equipment to operate the Gateway and collect status and performance data are located in the electronics facility. Function Performed : The Gateway supports voice communications, paging, and data transmissions. Position location services are also supported. The Globalstar Gateway connects the Globalstar space segment to terrestrial switching equipment. The Gateway receives telephone calls from the terrestrial switching equipment and generates Code Division Multiple Access (CDMA) carriers to transmit through the satellite. The satellite then re-transmits the signal to User Terminals. These User Terminals may be either hand held, fixed or mobile and located anywhere within the satellite antenna footprint. 2-9 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 In the return direction, the User Terminal transmits to the satellite(s) and the satellite(s) re-transmit the signal to the Gateway. The Gateway connects the call to terrestrial switching equipment, which can then connect to any subscriber using the standard telephone system. Connections can also be made to terrestrial cellular subscribers or to other Globalstar User Terminals. The Gateways are designed to operate without operator intervention. Maintenance is performed by service provider personnel as required. Status may be remotely monitored by the Service Provider's Control Center (SPCC). Functions of the major elements of the Gateway are listed below. Telemetry and Control Unit (TCU): The TCU acts as a telemetry and control interface between the satellite constellation and the SOCC. The TCU interfaces with the SOCC via the router in the GMS. The TCU interfaces with individual satellites via the GTS and the GRS. Gateway RF Subsystem (GRS): The GRS interfaces the gateway to Globalstar users via the Globalstar satellite constellation. Gateway Management Subsystem (GMS): The GMS interfaces the gateway with external management entities (SPCC). The GMS performs non-real-time configuration and management of the gateway. Call Detail Access (CDA): The Call Detail Access (CDA) is a separate, fault-tolerant workstation within the GMS, with stricter reliability requirements than the rest of the GMS. The CDA uses a confirmed-transfer protocol to retrieve accounting from the SBS, CCP and GC. CDMA Subsystem (CS): The CS performs real-time operation of individual calls, maintaining the integrity of each physical link and performing physical layer format conversion between the CDMA wave form on the GRS side and PSTN signals on the GSS side. Gateway Controller (GC): The GC is responsible for operation and supervision of the CS and of the GRS. Gateway Transceiver Subsystem (GTS): The GTS is responsible for the physical layer implementation of the Globalstar Air Interface. Under the control of the GC, control elements in the GTS set up and operate overhead and traffic channels as required. CDMA Interconnect Subsystem (CIS): The CIS provides packet-level and timing reference connectivity between all subsystems in the gateway. Selector Bank Subsystem (SBS): The SBS provides an interface between the SSA and the CS, and performs layer two operation and radio link management of individual traffic channel circuits. The SBS also performs service option-specific processing of traffic channel data. Service options may include voice, data, and short message services. 2-10 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Base Station Controller Interface (BSCI): the BSCI provides an interface between the CDMA Subsystem (CS) and the GSM MSCs. The BSCI implements the BSC side of the A1 Interface, providing the SS7 transport, the protocol discrimination function, BSSMAP processing, and passes the DTAP messaging between the GSM MSC and the CS. The BSCI can be configured to terminate multiple A1 Interface links between multiple GSM MSCs. The configuration and setup of the BSCI is controlled through the GMS interface (by way of the CS). Time and Frequency Unit (TFU): The TFU provides a highly reliable and stable source of timing and frequency references to the CS and to the GRS. The TFU output is synchronized to the Global Positioning System (GPS). Gateway Switching Subsystem (GSS): The GSS interfaces the gateway to the PSTN and controls the state of each call. Separation of CDMA & Switch: Although not often done, it is technically feasible to separate the Selector Bank Subsystem from the switch equipment. The interface between the two elements is an unformatted T1. Communications Service Units (CSUs) could be used at this point to separate the switching subsystem from the remainder of the gateway. 2-11 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 2.4 User Terminal and Gateway Interaction Hand Off: The moving satellite constellation requires hand off to different satellites and to different beams. In general, hand off is transparent to the user. Hand off on the forward link does not imply hand off on the return link. Forward Link: In the forward link direction (from the Gateway to the User Terminal), hand off is totally under control of the Gateway. The User Terminal finds pilots and reports quality to the Gateway. When a second pilot is seen, the quality is reported to the Gateway. If the Gateway determines that it is advisable, the Gateway will instruct the User Terminal to incorporate the signal into the diversity combiner. At all times the user terminal is using a fast algorithm to search for other pilots. Once a suspected pilot is detected, it is turned over to one of the fingers used as a clincher. So at one point in time, the User Terminal may have 3 fingers active. One is the traffic finger, one is used for diversity combing and the third finger is used as the clincher. In the forward direction the role of the User Terminal can be summed up as the proposer. The Gateway can be viewed as the disposer. The User Terminal suggests which pilots should be used. The Gateway decides. Return Link: In the Return Link direction, the Gateway uses up to 6 fingers. Eb/No is measured. If the Eb/No is above a usable threshold it is added into the diversity combiner multiplex. New signals are added in until the Gateway runs out of fingers. A stronger signal will not cause the Gateway to take a weaker signal out of the diversity combining process as long as it is above the threshold. Once a signal drops below the acceptable threshold, it will be taken out of the diversity combining process and the finger released for assignment to other incoming User Terminal signals. Soft Hand Off: In soft hand-off, two or more received signals through different links are simultaneously demodulated, combined, and decoded by the same entity. It is characterized by commencing communications using a new pilot on the same CDMA frequency before terminating communications with the old pilot. This is a hand off occurring while the user terminal is operating on the Traffic Channel. Hard Hand Off: In hard hand off, the receiving entity stops demodulating and decoding information transmitted on one link and starts demodulating and decoding information transmitted on another link with possible loss of information. A hard hand off is characterized by a temporary disconnection of the Traffic Channel. Hard hand off occur when the user terminal changes frequency or frame offsets. The temporary disconnect does not mean the call is dropped. There is sufficient hysteresis in the system to avoid dropping the call. Access Channel: The access channel is slotted aloha (TDMA). It does not use diversity. This channel is activated by the User Terminal to contract the gateway in the event the User Terminal is attempting to initiate a call. 2-12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Description of the Globalstar System GS-TR-94-0001 Revision E 2.5 Globalstar Control Centers There are two operations control centers. Each is completely capable of operating the network and managing the satellite constellation. There are two to circumvent the possibility of earthquake, power grid failure or other disaster. One is located in San Jose, California and one is located near Sacramento. Each includes:

1. Ground Operations Control Center. 2. Satellite Operations Control Center 3. Globalstar Business Office The integrated control center is shown below in Figure 2-9 Figure 2-9 Globalstar Control Center 2-13 1 2 3 4 5 6 7 8 9 10 11 12 13 Description of the Globalstar System GS-TR-94-0001 Revision E 2.5.1 Ground Operations Control Center Ground Operations Control Centers (GOCC) are responsible for planning and management of the communications resources of the Globalstar satellite constellation. This is coordinated with the Satellite Operations Control Center (SOCC). Figure 2-10 illustrates how the Ground Segment Equipment operates together to support Globalstar Communications Functions. paging power control Relays signalling from gw to users pilot synch Relays signalling from user to gw Access request Power change request Registration Relays communications ephemeris update

- Downloads Planning C-BAND Real Time connect user to switch signalling voice & data comm manage within resources data for billing Provides orbits Satellite health Battery state generate traffic plans allocate resources satellite gateway monitor performance Selects filters Sets gains Gat e w ay

( GW ) Ground Operations Control Center

(GOCC) Satellite Operations Control Center

(SOCC) Globalstar Data Network (GDN) S-BAND

(forward) L-BAND

(return) signalling voice & data communications multi-mode - including cellular File: CommFunc Figure 2-10 Ground Segment Support for Communications The GOCC and the SOCC may be collocated or they may be physically separated with linkage via the Globalstar Data Network as shown in Figure 2-10. If the two are collocated, the connection will be by a Local Area Network (LAN). In either case, the GDN connections are required to accommodate failure scenarios. These collocations will reduce long term personnel costs since both the GOCC and the SOCC are manned facilities. Figure 2-11 is a simplified block diagram of the Ground Operations Control Center (GOCC) 2-14 Description of the Globalstar System GS-TR-94-0001 Revision E Resource Allocation Management Applications Remote Display Operations High Performance Computer Work Stations Remote Display Work Stations Systems Admin. Console GPS Rcvr Local Area Network

(redundant) GDN 4 mm Tape Subsystem File Server Backups and Archives Disks Printers &

Scanners Processor Large Screen Display Visitor Display Local SOCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Figure 2-11 GOCC Simplified Block Diagram In addition to the planning functions, the GOCC is responsible for monitoring performance and ensuring that the Gateways remain within the allocated satellite resources. Appearance: The Ground Operations Control Center consists of a number of workstations in a control center environment. Besides the workstations used by the operators, there are other displays in the control center. 1. There are large screen remote displays located in the area. The computer operators can project any of the screen displays onto the large screen displays and continue operations. The large screen displays will update as the status changes. 2. There is also a large display that shows the position, coverage and status of the space segment. 3. A separate animated communications network display indicates the number of circuits flowing through Globalstar and indicates any congestion or circuit outages. Function Performed: The Ground Operations Control Center (GOCC) is the planning element for the Globalstar communications system. The redundant GOCCs plan the communications schedules for the Gateways and control the allocation of satellite resources to each Gateway. The Gateways process real time traffic within these assigned resources. The GOCC incorporates facilities to:

2-15 Description of the Globalstar System GS-TR-94-0001 Revision E 1. Generate long-range plans based on projected traffic requirements and constraints such as available frequencies, Gateway capacities, service areas, etc. 2. Monitor usage and refine plans based on measured performance of the system and constraints imposed by the SOCC. 3. Report satellite usage to the Satellite Operations Control Center. The GOCC facilities are operated 24 hours per day. Emergency Power: Critical elements of the ground equipment require a no-break power source or some form of backup power. 1 2 3 4 5 6 7 8 9 2-16 Description of the Globalstar System GS-TR-94-0001 Revision E 2.5.2 Satellite Operations Control Center The Satellite Operations Control Center (SOCC) manages the satellites. Redundant SOCCs control the orbits and provide Telemetry and Command (T&C) services for the satellite constellation. In order to accomplish this function on a worldwide basis, the SOCC communicates with T&C units collocated at selected Gateways. The T&C units share the RF links with the Gateway communications equipment to relay commands and to receive telemetry. Figure 2-12 illustrates how the various elements of the Globalstar Ground Segment operate together to support the command and telemetry functions. T ransmit satellite telemetry R eceives & acts on commands D ecrypts S tores if time tagged C-BAND T racks satellites P rogram track S ends commands R eceives telemetry A llocates satellite resources to GWs P rovides gateway T racking schedules Gateway

(GW) TCU Ground Operations Control Center

(GOCC) E ncrypts commands M onitors telemetry O rbit determination I nforms GOCCs S atellite available S atellite capacity S atellite ephemeris Satellite Operations Control Center

(SOCC) File: ContFunc Globalstar Data Network (GDN) Figure 2-12 Ground Equipment Support for T&C Functions Telemetry Down link and Command Up link: Globalstar satellites continuously transmit telemetry data, which contains orbit position data and measurements of current on-board health and status of the spacecraft. Because both the telemetry stream and the communications payload feeder links will utilize C-band communications, T&C operations utilize antennas and RF-equipment at selected communications Gateways. Since only selected Gateways have T&C units, telemetry is available only when an antenna with a T&C Unit is tracking the satellite. All Gateways equipped with T&C Units have the ability to command the satellite. The T&C unit consists of special purpose RF cards and a DSP controlled by a Pentium based Personal Computer. A single self-contained rack will accommodate up to 5 T&C Units (1 spare). The T&C units are designed to run automatically, with 2-17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 control from the SOCC. Routine staffing is not required. Any maintenance will be provided by service provider personnel dispatched on call from the Globalstar Control Center (GCC). Telemetry Reception: Telemetry from each satellite will be received at the T&C Gateway that have an antenna trained on that satellite. The T&C unit will be able to either directly send the demodulated data (bent-pipe mode) or store it for later transmission (store and forward mode). Stored data will be sent to the SOCC upon SOCC request, typically during a period of lower system utilization or lower communications network costs. The SOCC will coordinate the T&C data transmission to avoid receiving identical data sets from multiple T&C sites. The telemetry data sent from the T&C site is routed to the SOCC as packet messages on the Globalstar Data Network (GDN). Should more than one SOCC be providing support, the T&C equipment will route the data to multiple destinations. Command Transmission: Commands received from the SOCC are immediately transmitted to the satellite (bent pipe mode only). Depending upon the command, the satellite can execute the command immediately or store the command for execution at a later time. The TCU does not incorporate a command storage facility. The SOCC is responsible for directing the command message to the proper T&C at the correct time for transmission. SOCC Operations: The SOCC will receive minor frames over the Globalstar Data Network. Data received in the telemetry bent-pipe mode is immediately routed to the user workstations assigned to monitor or control the specific satellite. At any one time, all satellites in contact are automatically monitored by the software, with only selected satellites directly monitored by a member of the flight operations team. A single workstation can monitor up to 6 satellites. An operations controller may have asked for up to 6 specific satellites to monitor or may have defined the criteria by which the system can automatically determine which satellites are to be monitored. For example, the controller could request to see all satellites for which real-time data is being received for which the power subsystem monitoring software detects a possible area of concern. Because of the very low telemetry rates, it is possible to have remotely located workstations, connected to the SOCC via simple modem or ISDN communications. A workstation at the satellite manufacturer's facility, for example, could routinely be used to monitor a single satellite to support problem investigation, routine monitoring, or analysis. The SOCC is also responsible for coordinating activities with the GOCC. The three primary interface functions are:

a. Orbit position information: The SOCC will provide information to the GOCC so that each Gateway can accurately track each satellite. The data will consist of data tables sufficient to allow the Gateway software to generate its own contact lists. b. Utilization statistics: The GOCC will provide statistics to the SOCC pertaining to the actual communications quality and utilization (Gateway assessment) of each satellite. This information will be correlated with satellite telemetry to distinguish between expected and anomalous behavior. 2-18 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 c. Spacecraft status: The SOCC will report to the GOCC spacecraft/transponder availability. This data will include limitations associated with any satellite, which may constrain or preclude its use for communications. Use of Multiple SOCCs : Two SOCCs are planned. The San Jose, California location will support primary operations and a second one in El Dorado Hills, California serves as a backup to the prime. Both SOCCs will be able to receive telemetry data from the same satellites so that dual-site monitoring and "hot backup" functions could be supported; however, the baseline is a single string SOCC operation. The main reason for the second SOCC is to create a backup operational facility in case of a catastrophic failure (fire, etc.) at the primary site. The two SOCCs, however, could be used routinely to share the load between two sites, to conduct training and to support development and test of software upgrades. 2.5.3 Globalstar Business Office To support the Globalstar Business Office (GBO), the Globalstar Accounting & Billing System (GABS) is collocated with the GOCC and the SOCC. The GABS is responsible for all financial activities associated with Globalstar. Appearance: The GABS is a client/server system with many workstations and the requisite office facilities required to support the assigned accounting and billing activities. The server for the primary GABS is located in the GCC. A back-up GABS server is located in the alternate GCC. Multi-

platform client support is provided. Functions: The GABS provides basic accounting and billing functions for GLP. The accounting functions are provided by a Commercial - Off - The - Shelf (COTS) package, ORACLE Financial, and include accounts payable, accounts receivable, general ledger, purchasing , and financial planning software. The wholesale billing function, provided by custom developed software, receives data from both the Gateways and the Service Providers. These data, call usage summaries, subscriber counts, etc. are used to calculate charges for usage of the Globalstar system and to generate bills which are sent to the service providers monthly. 2-19 Description of the Globalstar System GS-TR-94-0001 Revision E 2.6 Globalstar Satellite The Globalstar satellite is a simple low cost satellite designed to minimize both satellite costs and launch costs. A pictorial of the satellite and some of the major characteristics are shown in Figure 2-13. STRUCTURE Rigid Al Frame Al Honeycomb Panels MASS

<450 kg (Wet) ELECTRICAL POWER 1.1 kW EOL Solar Array Single-Axis Track(Rotate) Peak Power Tracker 14-23 V Unregulated Bus Ni- H2 Battery, 14 Cells, 64 Ah THERMAL Generally Passive Heat Pipes Thermostatic Control Heaters PROPULSION Mono-Hydrazine (76.6 kg) Blow Down Regulation (4:1) Passive Management Device 5-1 Newton Thrusters ON-BOARD PROCESSING 1750 A 16 BIT, 1.8 MIPS, 64K SRAM

& 128K PROM 16K SUROM RS422 & RS485 I/O ADA 8K Safeguard Memory (SGM) RELIABILITY Ps = 0.85 for 7.5 years, providing 15 of 16 beam pairs AUTONOMY FDIR Safe Mode (Earth & Sun) TELEMETRY & COMMANDING C-Band CMD/TLM - 1.0 KBPS Real Time, Stored and Macro CMD Encryption - KI - 23

<500 Hardware Commands

<500 Hardware Telemetry Items ORBIT DETERMINATION GPS Tensor (<90 M. Semi-Major Axis) ATTITUDE DETERMINATION ( 0.7 half cone) Earth Sensor Magnetometer 3 Sun Sensors ATTITUDE CONTROL (NORMAL) Yaw steering & Momentum Bias 4 Reaction Wheels Mag. Torquer along X&Y Figure 2-13 Spacecraft Bus Characteristics - Highly Autonomous Communications Payload : A pictorial of the communications payload is shown in Figure 2-14. 1 2 3 4 5 6 2-20 Description of the Globalstar System GS-TR-94-0001 Revision E S-BAND TRANSMIT ANTENNA Satellite to User Active Phased Array 91 Elements Frequency = 2483.5 to 2500 MHz Max. SSPA RF 4.2 Watts L-BAND RECEIVE ANTENNA User to Satellite Active Phased Array 61 Elements Frequency = 1610 to 1626.5 MHz C-BAND XMT/RECEIVE ANT. Scalar Horn Bi-Polarized, 8 channels per Transmit Freq. = 6875 to 7053 MHz Rec. Freq. = 5091 to 5250 MHz COVERAGE (ALL BANDS & ANTENNA) Fill subtended angle = 108 deg

(with respect to satellite nadir) Beam Configuration (S-Band) Generally Isoflux 16 Beams 1 - Central Beam Radius 16 deg 6 - Middle Beams to 37 deg 9 - Outer Beams to 54 deg Beam Configuration (L - Band) Generally Isoflux 16 Beams 1 - Central Beam 22.5 deg 15 - Outer Beams to 54 deg COMMUNICATIONS CHANNEL 16 total channels 1 channel per beam Each channel is 16.5 MHz with 19.38 MHz centers S-BAND ELECTRICAL POWER Continuously Payload senses SSPA input power level and adjusts transmit power Dedicated high efficiency TELEMETRY & COMMANDING C-Band for command & telemetry Telemetry 1 of 12 selectable carriers uniformally spaced Single command frequency with unique satellite ID MASS

<154 kg 1 2 3 4 5 6 7 Figure 2-14 Communications Payload Pictorial The communications payload is a simple bent pipe communications package as shown in Figure 2-15. RET U RN T RA N SPON DER R ETU RN LINK F ROM U SER S W I T C H S AW S AW S AW S AW S W I T C H L -B AN D RX ACT IVE A NT ENNA L- C BAND C BAN D SSPA FREQU E NC Y CONVERSION SEC TION MA ST ER F RE QUE NC Y TLM GENERATOR C-S B A ND FR EQUE NC Y C ONVERSION SEC TION FOR WA R D TR AN SPON D ER C MD FOR WA RD LINK T O U SER S-B A ND TX ACT IVE A NT ENNA File: Sat C omm D I P L E X E R D I P L E X E R RE TUR N LIN K TO GAT EWAY FO RWAR D LIN K FROM GAT EWAY C BAN D LN A Figure 2-15 Communications Payload Simplified Block Function Performed : A User Terminal transmits to the satellite by L-Band. The signal enters the satellite through the L-Band low noise amplifier. It is amplified and then converted into a C-Band signal 2-21 Description of the Globalstar System GS-TR-94-0001 Revision E after which it is further amplified. This is radiated to the Gateway. The Gateway receives the signal and block down converts to an intermediate frequency. A sample of the intermediate frequency is provided to the TCU for processing. The communications traffic is presented to the CDMA equipment for demodulation. In the forward link direction, the Gateway combines the up link CDMA signals with the signal from the command transmitter and radiates it at C-Band up to the satellite. The satellite then down converts the signal and radiates an S-Band down link signal to the User Terminals. Telemetry & Command : The Telemetry and Command carriers share the C-Band with the communications feeder links. Figure 2-16 is a simplified block diagram of the T&C package on the satellite. CMD Channel Extractor Input Filter

(LHCP) AE CMD Filter To C-Band LNAs AE CMD Antenna LNAs Command Receiver DC/DC Command Receiver DC/ DC Data (NRZ-L) RS-422 OBPE Clock Squelch Data (NRZ-L) Clock Squelch Command Decoder Command Decoder RS-422 TLM channel Insertor Data (Manchester) RS-422 Telemetry Transmitter DC/DC Data (Manchester) RS-422 Telemetry Transmitter DC/DC Telemetry Encoder Telemetry Encoder OBPE From C-Band SSPAs Output Filter

(LHCP) AE TLM Filter AE TLM Antenna Figure 2-16 Satellite T&C - Compatible with Communications The T&C connects to the normal C-Band communications antenna for on-orbit operations. There is also a T&C antenna on the anti-earth face of the satellite. This antenna functions when the satellite is not 2-22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 oriented correctly or when there are problems. The anti-earth antenna is to ensure that telemetry can be obtained and commands entered under all recoverable contingencies. Note that the anti-earth antenna bypasses the Low Noise Amplifier. This means that the transmitted power from the commanding earth terminal will have to be higher than the normal power required for commanding. This can be accommodated because there is no communications traffic when the satellite is not oriented correctly. Yaw Steering: The satellite is steered in yaw to keep the solar panels oriented toward the sun to extract the maximum energy. This increases the communications capacity of the Globalstar System. There are some minor penalties that cause a slightly slower acquisition time and may cause more hand offs than would be otherwise required. 2-23 Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 2-24 Description of the Globalstar System GS-TR-94-0001 Revision E 3. FREQUENCIES AND COVERAGE ANALYSIS 3.1 Frequency Plans Globalstar uses C-Band between the Gateway and the Satellites as shown in Figure 3-1. TO USER TERMINAL 16 BEAMS TO GATEWAY 6875 MHz 7055 MHz 180 MHz LHCP S-B and LHCP 2483.5 MHz 16.5 MHz Satellite Transponder Channel Beam 2500 MHz T L M X1 X2 X3 X4 X5 X6 X7 X8 8 10 4 6 1 14 2 12 RHCP Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 Channel Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 9 11 13 15 8 3 7 5 Beam 3 15 13 11 5 9 7 16 16.5 MHz RHCP 19.38 MHz X1 X2 12 14 X3 16 X4 10 X5 X6 X7 X8 Channel 1 6 4 2 Beam Satellite Transponder 16.5 MHz LHCP 159 MHz L-Band 1610 MHz LHCP 1626.5 MHz C m d 5091 MHz 5250 MHz Fil e: Fr eq Pl an FROM GATEWAY FROM UT Figure 3-1 Frequency Plan - Emphasizes Conservation of Spectrum The C-Band antennas on the satellite use an earth coverage beam. The Gateways use a parabolic antenna and program track the satellites. Program tracking uses the orbital data provided by the Satellite Operation Control Center to position the Gateway antenna. Efficient Spectrum Utilization - The spectrum is used efficiently by incorporating frequency reuse and spread spectrum into the design. Both Right Hand Circular Polarization (RHCP) and Left Hand Circular Polarization (LHCP) are used for C-Band. This allows 8 frequencies to 1 2 3 4 5 6 7 8 9 10 11 3-1 Description of the Globalstar System GS-TR-94-0001 Revision E connect to 16 beams on the satellite. The beam numbers shown in Figure 3-1 map to the S-Band beams shown in Figure 3-2 and the L-Band beams in Figure 3-3 which follows. The alpha characters used within the spectrum blocks and on the following diagram indicate polarization. X= Left Hand Circular Polarization Y= Right Hand Circular Polarization 3.2 Satellite Antenna Beam Configuration The S-Band antennas on the satellite are configured to produce 16 beams as shown in Figure 3-

2.

+ Ysc View from Satellite Looking at Earth Nadir X1 Y3 X7 Y8 X2 Y6 X5 X6 Y4 X8 Y7 X3

+ Xsc Y2 X4 Fil e: S -B eams Y1 Y5 X= LHCP Y=RHCP 1 1 1 0 1 2 4 3 1 2 9 1 3 5 7 8 14 6 15 16 Channel Assignments Beam Assignments Figure 3-2 S - Band Beams The antennas are multiple beam antennas designed to provide an isoflux pattern on the earth in the service region. The isoflux pattern is obtained by shaping the beam so that the gain at the edge of coverage is higher than at the beam center. This compensates for the difference in losses due to the longer slant range at the beam edges. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 3-2 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 L-Band Pattern: The L-Band pattern consists of 16 beams. Beam 1 is in the center. The remaining 15 beams are arranged in an annular ring around the center beam as shown in Figure 3-3.

+ Ysc View from Satellite Looking at Earth Nadir Y6 X2 X1 Y4

+ Xsc Y7 X4 Y5 X5 X8 Y3 X6 X3 Y2 Y1 Y8 X7 Fil e: L-B eam s X= LHCP Y=RHCP 8 7 6 5 4 9 1 0 1 1 1 2 1 3 14 15 1 3 16 2 Ch annel Assign men ts B eam Assignments Figure 3-3 L- Band Beams This configuration provides better coverage on the earth to reduce the power requirements on the L-Band transmitters in the User Terminals. 4 5 6 7 3-3 Description of the Globalstar System GS-TR-94-0001 Revision E Efficient Spectrum Utilization - As shown in Figure 3-4 and Figure 3-5, only 16.5 MHz of L-

Band and S-Band spectrum are used. The same set of frequencies are reused in each of the 16 beams. Note that C-Band frequencies are assigned to beams to minimize interference. The Globalstar approach is very efficient in its use of the valuable L-Band and S-Band spectrum. L-

Band is used to communicate from the User Terminal to the satellite and S-Band is used to communicate from the Satellite to the User Terminal. Within each of the beams, there are 13 FDM channels. 161 0.0 MHz 162 6.5 MHz 161 1.960 MHz 16 14.42 0 MHz 16 16.88 0 MHz 16 19.34 0 MHz 16 21.80 0 MHz 16 24.26 0 MHz 16 10 .7 30 MHz 161 3.190 MH z 1615 .6 50 MHz 1 618.110 MHz 1620 .5 70 MHz 1623.030 MH z 162 5.490 MHz 1010 kHz 730 kHz 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 1.23 MH z 1.23 MHz 1 .2 3 MHz 1 .2 3 MHz 1.23 MH z 1.23 MH z 1.23 MH z Fil e: L- Band Frequencies 2 483 .5 MHz 16.5 MHz Figure 3-4 L - Band Channel 250 0.0 MHz 2 485.6 20 MHz 2488 .0 80 MHz 2 490.5 40 MHz 2 493 .0 00 MHz 249 5.460 MH z 2497.920 MH z 24 84.390 MHz 2486.85 0 MHz 2489.310 MH z 249 1.770 MH z 249 4.230 MH z 2496 .6 90 MHz 24 99.150 MHz 850 kH z 89 0 kHz 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 1.23 MH z 1.23 MHz 1 .2 3 MHz 1 .2 3 MHz 1.23 MH z 1.23 MH z 1.23 MH z Fi le:S -Band 16.5 MHz Figure 3-5 S - Band Channel Frequencies Spectrum Sharing - Within a channel, spread spectrum is used to convey the voice or data intelligence. Multiple voice or data circuits may be carried within a single 1.23 MHz FDM channel. The circuit data is separated by unique PN spreading sequences. This allows the same spectrum to be shared by other CDMA users. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 3-4 Description of the Globalstar System GS-TR-94-0001 Revision E Satellite Frequency Plan: Table 3-1 illustrates how the C-Band up link signals are converted to S-Band down link signals and indicates how the signals are connected to down link beams. The table shows the assigned C-Band Frequencies. Table 3-1 Satellite C-Band to S-Band C-Band Frequencies S-Band LHCP S-Band RHCP RF Freq.(MHz) L.O. Freq (MHz) Chan Beam Chan Beam 5105.21 5124.59 5143.97 5163.35 5182.73 5202.11 5221.49 5240.87 5091.50 7596.96 7616.34 7635.72 7655.10 7674.48 7693.86 7713.24 7732.62 X1 X2 X3 X4 X5 X6 X7 X8 CMD 12 14 16 10 1 6 4 2 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 9 11 13 15 8 3 7 5 Table 3-2 illustrates the how the Return link is processed in the Satellite. The table shows the assigned C-Band Frequencies. Table 3-2 Satellite L-Band to C-Band L-Band to C-Band L-Band LHCP L-Band RHCP RF Freq(MHz) L.O. Freq (MHz) Chan Beam Chan Beam 6908.99 6928.37 6947.75 6967.13 6986.51 7005.89 7025.27 7044.65 6876.0-6877.1 (12 ea.) 5290.74 5310.12 5329.50 5348.88 5368.26 5387.64 5407.02 5426.40 8 10 4 6 1 14 2 12 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8 3 15 13 11 5 9 7 16 X1 X2 X3 X4 X5 X6 X7 X8 TLM 3-5 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 Description of the Globalstar System GS-TR-94-0001 Revision E Command and Telemetry Frequencies: The telemetry frequencies are listed in Table 3-3 Table 3-3 Satellite Telemetry & Command Frequencies Command Channel Bandwidth 5091 to 5092 (*) Telemetry Channel Bandwidth 6875.95 to 6877.15 No. of Channels 1 No. of Channels 12 Channel Width(s) 240 KHz Frequency Center(s) 5091.5 Channel Width(s) 100 KHz Chnl No. 1 2 3 4 5 6 7 8 9 10 11 12 Frequency Center(s) 6876.0 6876.1 6876.2 6876.3 6876.4 6876.5 6876.6 6876.7 6876.8 6876.9 6877.0 6877.1 Doppler: The Frequencies that appear at the Globalstar nodes (Gateway, Satellite, UT) differ from the assigned frequencies. Doppler is one of the primary contributors. Doppler can be computed and the nodes can compensate for the differences in frequency. Table 3-4 indicates the magnitude of the Doppler components. Table 3-4 Worst Case Doppler Frequency Doppler Path Name From To

(MHz)

(KHz) Forward Uplink Gateway Satellite Fwd Downlink Satellite UT Return Uplink UT Satellite Return Downlink Satellite Gateway 5250 2500 1626.5 7052.9 97.2 46.5 30.2 131.6 Rate Hz/sec 468.8 224.3 146.0 634.9 3-6 Description of the Globalstar System GS-TR-94-0001 Revision E 3.3 Earth Surface Coverage The surface of the earth, with the exception of the polar regions, is covered with multiple overlapping satellite beams as shown in Figure 3-6. Figure 3-6 Full Earth Coverage-Except Polar Regions The contours shown indicate that a User Terminal within the contour can communicate with the satellite at an elevation angle above 10 degrees. Constraining the User Terminals to operate with satellites that have higher elevation angles referred to the User Terminal will reduce the overlapping coverage but would provide an advantage in that it would reduce the power demands placed on the User Terminal to close the link. This would result in longer battery life for the User Terminal. Conversely, lowering the angle to the satellite will increase the overlapping coverage. Small changes dramatically increase the coverage area. This is particularly apparent in the polar regions. If operated at low elevation angles, polar areas that otherwise could not be covered can 3-7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Description of the Globalstar System GS-TR-94-0001 Revision E receive service. In polar areas, overlapping coverage would be increased and power demands may be increased. In this region the look angle to the satellite is limited. High gain directional antennas become practical for fixed and even portable installations. The pay back is that Globalstar could now serve areas that otherwise might be unserviceable. To a degree, some of these same considerations discussed for polar areas apply to equatorial areas where the overlapping coverage is less than 100%. Satellites in View as a Function of Latitude: Figure 3-7 illustrates the multiple satellite coverage more clearly. Multiple Satellite Coverage Versus Latitude

(10 degree elevation angle, 48 satellite constellation) 1 or more 2 or more 3 or more 4 or more 100.0 90.0 80.0 70.0 60.0 50.0 40.0 30.0 20.0 10.0 0.0 e m T i f o

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 Latitude USA (CONUS) CENTRAL EUROPE SCANDINAVIA AUSTRALIA 9408061 Figure 3-7 Enhanced Coverage for Temperate Regions Note that the coverage is optimized to provide multiple coverage in the temperate regions. In areas within this temperate region, the User Terminal can communicate via multiple satellites. This enhances the link availability and allows the User Terminal to operate with nominal link margins. 3-8 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 Orbital Parameters: The orbital parameters for the initial injection orbit and for the final on station orbit are shown in Figure 3-8. Parameter Radius (km) On Station Phasing Orbit Mean 7778 Tol (3 8 ) Mean Tol (3 8 )

+/- 0.1 7298

+/- 20 Orbit Period-Nodal 114 min

+/- 0.13 sec 103.35

+/-0.4 Eccentricity 0.000

+ 0.008 0.000

+ 0.01 Inclination (Degrees) RAAN Spacing for plane J=1...8 (Degrees) Relative Phasing between satellites in a plane (Degrees) Relative Phasing between adjacent planes (Degrees) 52 45 60 7.5

+/- 0.01 52

+/- 0.6

+/- 1.0

+/- 1

+/- 1 File: Orbi tp Rev 11 /0 6/96 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Figure 3-8 Orbital Parameters for Globalstar Satellites Supplementary Coverage: There are two problem areas in the coverage. 1. One is over the equator where the beam is narrow. There has been some study of using some additional satellites to cover the equatorial area. At this point in time, this is not financially justified. If more business is identified as we penetrate Indonesia, the Philippines, India, Central Africa, and Central America enhanced coverage may be examined again. 2. The second area that is not covered well is the polar area. Some study of supplementing coverage with Molniya orbit satellites has been performed. This type of orbit hangs in the polar areas for a long period and then orbits over the south polar area very rapidly. If coverage of the northern areas becomes economically justified, this may be re-visited. The other thing to be considered in northern areas, such as the islands north of mainland Russia, is the inclination of the satellites. They do not go beyond 52 degrees north. This means a fixed UT antenna can be pointed south only. Gain can be obtained due to the directivity. Fixed User Terminals could operate much further north if they do not require an omni-directional Fixed User Terminal antenna. 3-9 Description of the Globalstar System GS-TR-94-0001 Revision E 3.4 Position Determination The location of the User Terminal is determined by Globalstar and used for several purposes. Any position location services that may be provided should be considered a by product of the Globalstar System. The primary purpose of Globalstar is to provide communications. It should not be considered as a competitor or replacement for GPS or GLONASS. Two basic accuracy are supported. Low Accuracy: The user terminal is located to within 10 km for purposes of National Sovereignty, to assign the user to a gateway, and to support registration. This accuracy is sufficient for the gateway to determine which satellite/beam should be used for phone paging. This avoids having to page on multiple satellites/beams at the cost of capacity. High Accuracy: A higher accuracy on the order of 300 meters is feasible in under some conditions. This may be attractive as a service. This high accuracy results from the high degree of precision with which the position and velocity of the satellite constellation is know. Each satellite incorporates a GPS receiver to determine position and rate of change of position. When this data is processed with other data at the SOCC the precision of the orbit becomes quite good. The CDMA, for its own purposes, needs to align chips within 1/8 of a chip. Potential for high positioning accuracy is inherent. The User Terminal may determine its position with the assistance of the Gateway or it may determine its position autonomously. In all cases, determination of position is based on determining the intersection of three or more spheres in 3-dimensional space. The surface of the earth can be used as one of the spheres. The Gateway has the processing power to make active determination attractive. This must be traded for additional messaging that will be required to support active determination of position. Active Determination: The Gateway calculates range based on time delay between the User Terminal and the Gateway through a satellite. The phone transmission can be an access probe or an ongoing call, but it must be synchronized in some fashion to the forward link signal. When this accomplished through two satellites with the proper geometry, excellent positioning accuracy can be achieved. Passive Determination: The User Terminal can determine its location without the assistance of the Gateway. In this mode, since time is not known very well this means the system has an extra degree of freedom. The phone measures a T between two different satellites, and another T using a third satellite. Three 3 satellites are required, to solve for the phone's clock offset. An additional form of passive position determination incorporates measurements of the satellite velocities relative to the phone, instead of or in addition to the satellite ranges to the phone. This is done by measuring the received Doppler shift of the satellite signal. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 3-10 Description of the Globalstar System GS-TR-94-0001 Revision E Any of the techniques must incorporate the following generic considerations. Geometric Dilution Of Precision (GDOP): This is a phenomenon that affects all forms of position determination. It is due to the orientation of the satellites from the phone's perspective. When the geometry is good, precision is good. When poor, the accuracy degrades very quickly. Time to Position: Time to achieve an accurate position depends on the time. In simple forms, the more time the more precise the location. Geographical Constraints: Position determination becomes more difficult when the User Terminals are on the equator or at high latitudes. In these cases, only one satellite may be visible. This means that range must be determined at one point in time and the range determined again at another point in time. Under these conditions the geometry is less than optimal, resulting in a long time to achieve a valid position determination and an inaccurate determination of position. Terrain Maps: For the surface of the earth to be used as one of the intersecting spheres, a terrain map must be used to determine altitude above the mean surface of the earth. The degree of granularity of this map will impact the accuracy that can be achieved and will impact the time to achieve a position indication. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 3-11 Description of the Globalstar System GS-TR-94-0001 Revision E 3.5 Channel Characteristics Figure 3-9 illustrates the orientation of a User Terminal in a typical temperate climate scenario with multiple satellite coverage. Globalstar 1 Globalstar 2 S2 S2 S1 S1 Channel 5 Channel 5 Globalstar Gateway Globalstar Handset Decoder

Vocoder RECEIVER 1 COMBINER RECEIVER 2 RECEIVER 3 Figure 3-9 Channel Characteristics Considerations Line of Sight: For the Globalstar system, many of the obstructions in the direct line of sight do not completely block the line of sight, but rather simply attenuate the signal. Given two satellites in view at the same time, the probability of signal blockage or shadowing to both satellites is significantly less than the probability of blockage to a single satellite. 3-12 1 2 3 4 5 6 7 8 9 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Specular Reflection: The specular reflection component is the signal reflected off the surface of the earth. The magnitude of the reflected signal can be large if the surface is relatively smooth and flat at the point of reflection. The specular component will prove to be an insidious problem for the hand held antennas. It can either add to or subtract from the signal received from the direct line of sight. This problem can be managed effectively for the mobile and the fixed station antennas. Diffuse Reflection: The diffuse component is composed of a sum of a large number of individual terrain scatter from outside the first Fresnel zone. This diffuse component is characterized by phase incoherent multi-path with a uniform phase distribution and a Rayleigh amplitude distribution. The signal fading associated with the diffuse component combining with the direct component produces the fast-fading characteristics of the propagation channel. Building Penetration: Globalstar has limited ability to penetrate buildings. Operation is possible in wood frame buildings or near windows with a wide angle view of the sky. The best locations within building results in 6 to 13 dB added insertion loss. There is a high degree of sensitivity to antenna location within the building. A change in lateral position of 20 to 30 centimeters can produce a 30-dB variation in signal power. In Pocket: With the antenna extended, operation depends on orientation. Body blockage can insert attenuation in excess of 15 dB. If the antenna is stowed, operation is not considered feasible. Interference: User Terminal receivers may experience interference when operating in close proximity to microwave ovens, plywood plants or hospitals. The transmitters are frequency coordinated for operation with Radio Astronomy sites, for operation with GPS, and with GLONASS. The Gateway site locations are selected to avoid interference with the Microwave Landing Systems (MLS) associated with airports. Conclusions: Several Conclusions can be drawn for Globalstar operations. 1. Operation at higher elevation angles is preferred. 2. Mobile will suffer less from specular. Power control may be less effective at some operating speeds. 3. Fixed terminals will suffer less degradation from all sources. 4. Forward and Return link behavior are not correlated. Conclusions from one direction cannot be used to derive control information for the other direction. 3-13 Description of the Globalstar System GS-TR-94-0001 Revision E 3.6 Link Analysis The Globalstar system provides spatial diversity to overcome shadowing and blocking. The link analysis in this section is based on the current FCC filing which assumes nominal 5.5 meter antennas at the Gateways. There are 3 cases that are presented. Case 1: This is a detailed link budget. This case considers the forward and return links between the Gateway to the User Terminal. The up link from the Gateway to the satellite is C-Band. The down link from the satellite to the User Terminal is S-Band. The Return Link is L-Band from the User Terminal to the Satellite and C-Band from the satellite to the Gateway. There is no shadowing or blocking and diversity is used. Case 2: This is an abbreviated link budget that shows only the differences from case 1. One path is blocked. Only the C-Band or the S-Band can be blocked; since, the Gateway will be in one location. Case 3: This is a rare case where both links are shadowed or faded by 10 dB. Table 3-5 Forward Link C-Band - Case 1 - Detailed Budget Up Link Gateway to Satellite C-Band Frequency Nominal EIRP per user Path loss(40 degree. GW elev.) Polarization & Tracking. Loss Satellite Antenna gain (incl. line loss) Receive power/user at LNA Average User Data Rate System Noise Temperature Thermal Noise Density, No Estimate Interference Density Up link Eb/(No+Io) 5125.0 26.8

-172.5

-1.1 3.1

-143.7 2400.0 549.5

-201.2

-198.5 MHz dBW dB dB dB dBW b/s K dBW/Hz dBW/Hz 19.1 dB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 3-14 Description of the Globalstar System GS-TR-94-0001 Revision E 1 Table 3-6 Forward Link S-Band - Case 1 - Detailed Budget Down Link Satellite to User Terminal Frequency Nominal EIRP per user Satellite Altitude Typical Elevation Angle Range Free Space Loss Polarization & Tracking. Loss Shadowing Loss Receive Signal Strength /user/sat. User Antenna Gain(incl. line loss) User Signal at antenna output System Noise Temperature Thermal Noise Density, No Average Data Rate, Rb Down link Eb/No Interference per Channel Spreading Bandwidth

-10*log(spreading BW) Interference Density, Io Down link Eb/(No+Io) Coherent combining gain Overall Eb/(No+Io) (up&dn) Operating Eb/No 2 3 2495.0

-2.9 MHz dBWi 1414.0 km 50.0 degrees 1740.5

-165.2

-1.0 0.0

-169.1 2.6

-166.5 293.7

-203.9 2400.0 3.6

-148.6 1.23

-60.9 km dB dB dB dBWi dBi dBW K dBW/Hz b/s dB dBW MHz dB/Hz

-209.5 dBW/Hz 2.6 2.5 5.0 dB dB dB 5.0 dB 3-15 Description of the Globalstar System GS-TR-94-0001 Revision E Table 3-7 Forward Link - Case 2 - Link Blockage C-Band Up Link and S-Band Down Link Up link EIRP per user Up link Eb/(No+Io) Down link EIRP per user Down link Eb/(No+Io) Coherent combining gain Overall Eb/(No+Io) 28.8 21.1 dBW dB

-0.4 dBW 5.1 0.0 5.0 dB dB dB Table 3-8 Forward Link - Case 3 - Rare Two Link Fade C-Band Up Link and S-Band Down Link Up link EIRP per user Up link Eb/(No+Io) Down link EIRP per user Shadowing loss Down link Eb/(No+Io) Coherent combining gain Overall Eb/(No+Io) 36.3 28.6 dBW dB 7.1

-10.0 2.6 2.5 5.0 dBW dB dB dB dB 1 2 3 4 3-16 Description of the Globalstar System GS-TR-94-0001 Revision E 1 Table 3-9 Return Link L-Band - Case 1 - Detailed Budget Up Link User Terminal to Satellite Frequency Nominal EIRP per user Satellite Altitude Typical elevation angle Range Free Space Loss Polarization & Tracking. Loss Shadowing loss S/C Receive Signal Strength S/C Antenna Gain (incl. line loss) User Signal at antenna output System Noise Temperature Thermal Noise Density, No Average data rate, Rb Up link Eb/No Interference per channel Spreading bandwidth Interference Density Up link Eb/(No+Io) 2 1615.0

-11.2 MHz dBWi 1414.0 km 70.0 degrees 1487.1

-160.1

-1.0 0.0

-172.3 11.5

-160.8 500.0

-201.6 2400.0 7.0 km dB dB dB dBWi dBi dBW K dBW/Hz b/s dB

-142.2 1.23 dBW MHz

-203.1 dBW/Hz 4.7 dB 3-17 1 2 3 Description of the Globalstar System GS-TR-94-0001 Revision E Table 3-10 Return Link C-Band - Case 1 - Detailed Budget Down Link Satellite to Gateway Frequency Nominal EIRP per user Path loss (40 degree GW elev.) Polarization & Tracking. loss GW antenna gain Receive power/user System noise temp. Thermal noise density, No Interference Density, Io Down link Eb/(No+Io) Combining gain Overall Eb/(No+Io)(up&dn) Operating Eb/No 6975.0

-27.7 MHz dBW

-175.2

-1.1 49.4 dB dB dB

-154.5 dBW 127.7

-207.5

-212.3 18.0 1.8 6.3 K dBW/Hz dBW/Hz dB dB dB 6.3 dB Table 3-11 Return Link - Case 2 - Link Blockage L-Band Up Link and C- Band Down Link Up link EIRP per user Up link Eb/(No+Io) Down link EIRP per user Down link Eb/(No+Io) Combining gain Overall Eb/(No+Io)(up&dn)

-9.4 6.5 dBW dB

-25.9 19.8 0.0 6.3 dBW dB dB dB 3-18 Description of the Globalstar System GS-TR-94-0001 Revision E Table 3-12 Return Link - Case 3 - Rare Two Link Fade L- Band Up Link and C- Band Down Link Up link EIRP per user Shadowing loss Up link Eb/(No+Io) Down link EIRP per user Down link Eb/(No+Io) Combining gain Overall Eb/(No+Io)(up&dn)

-1.2

-10.0 4.7

-27.7 18.0 1.8 6.3 dBW dB dB dBW dBW dB dB Forward Link: The link from the Gateway to the User Terminal reduces self interference within an FDM channel by coherent transmissions and by using CDMA Walsh codes which are orthogonal. Return Link: The Return link uses paths through multiple satellites to combat the effects of shadowing, blockage and multi-path. 1 2 3 4 5 6 7 8 3-19 Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 3-20 Description of the Globalstar System GS-TR-94-0001 Revision E 4. CODE DIVISION MULTIPLE ACCESS (CDMA) 4.1 Introduction The Globalstar Air Interface uses a modified form of IS-95 to support Code Division Multiple Access. CDMA was selected for Globalstar because it represents a proven technology that can provide a bandwidth efficient modulation scheme for satellite communications. It is relatively interference tolerant, both from the standpoint of generation of interference to other services and tolerating outside interference. As a bonus, there is a level of security inherent in the modulation scheme. It is difficult to listen into conversations or to pirate services from the system. CDMA is able to provide good voice quality while operating at relatively low RF power levels. The Globalstar CDMA is based on the existing QUALCOMM CDMA product line used for terrestrial cellular communications. Path Diversity combats fades and blockage - Probably one of the most important aspects of CDMA is associated with the way Globalstar uses CDMA. Diversity combining is used to provide continuous communications even under conditions where a path to one satellite is totally blocked. The Globalstar system can operate with relatively low link margins and still provide a high link availability. CDMA supports spectrum sharing - There are other useful and interesting aspects of CDMA. In CDMA two or more systems can occupy the same frequency-power space. Separation of the intelligence is accomplished by demodulating the PN spreading sequence. This supports band sharing by more than one system. Soft Capacity Limit: There is another useful aspect of CDMA. Since CDMA is basically a system whose capacity is limited by self generated interference, the limit is a soft limit. Unlike bandwidth limited systems like Time Division Multiple Access (TDMA) or Frequency Division Multiple Access (FDMA), CDMA allows the predicted capacity limit to be exceeded with soft degradation occurring. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 4-1 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 4.2 Diversity Combining Diversity combining is used to mitigate the effects of link phenomena. In a simple form, diversity combining uses the signal with the best signal to noise ratio. Rake receivers are used to receive and combine the signals from multiple sources. As an example, the User Terminal will provide diversity combining for the forward link signals received through up to two different links simultaneously. Diversity increases Availability - The performance in the diversity mode will always exceed the performance that would be achieved with communications via a single string link. Diversity combining is continuous. There is no break in service if one or more of the diversity links is lost. Multiple Satellite - Forward Link: In the forward direction, the use of diversity brings substantial gain if one of the satellites is obstructed and is break even for unobstructed operation without multi-path. With multi-path fading (typically with high values of Ricean k) the diversity also provides benefit. Multiple Satellite - Return Link: In the reverse direction, there is a clear advantage because gain results even with no obstruction. Because this is non coherent diversity combining, the gain is not quite as much as with coherent operation. Multiple Beam - Forward Link: There is no diversity advantage for using multiple beams. All beams come from precisely the same point in the sky and are at the same sub-channel frequency. Whatever shadowing or multi-path occurs for one beam occurs for the other. Multiple Beam - Return Link: On the Return Channel the signals the gateway sees through the different beams are, of course, the same; they fade in exactly the same way. But the noise backgrounds in which they are received are essentially independent. There is some advantage to using diversity. 4.3 Fade Mitigation The Gateway will support power control to address slow fades and interleaving to address medium to fast fades. Power control is implemented on both the forward and return links. Power Control: To support forward link power control, the user terminal reports pilot quality statistics to the gateway. For return link power control, the Gateway measures frame error rate. The response time of the power control is adjusted to accommodate the satellite round trip time delays. Average round trip delay is on the order of 30 ms. Forward Link: Forward link power control is closed loop under control of the Gateway. The dynamic range of the forward link power control is at least 20 dB. Return Link: The return link is operated open loop when a fade is first sensed, then closed loop under control of the Gateway. The dynamic range of the return link power control is a 4-2 Description of a Globalstar Gateway GS-TR-94-0001 Revision E maximum of 20 dB with a 0.5 dB step size. The User Terminal will limit the integrated transmitted power to conform with regulatory requirements. Interleaver: The Interleavers will operate over a 20 ms vocoder packet frame which will effectively address medium and fast fades. 4.4 Acquisition Search to Acquire: When a Globalstar phone hunts for a pilot channel it must search through a multi-

dimensional space. Three of the more obvious dimensions are illustrated in Figure 4-1. PN Code PN Timing Frequency Doppler Figure 4-1 Acquisition Search Space The goal is to reduce the search volumes by all means practical. Given that the search volume is decreased; then parallel processing can be used to speed the search process without compromise to the probability of a correct acquisition. 1 2 3 4 5 6 7 8 9 10 11 12 4-3 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 Latitude Dependence: The acquisition time is also a function of other variables such as latitude as shown in Figure 4-2.

) s c e s

e m i T 6 5 4 3 2 1 0 PP S M e an PP S 9 5 %

0 2 0 4 0 6 0 L a t i t u d e ( d e g ) 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Figure 4-2 Acquisition Time as a function of Latitude The Search is latitude dependent due to the orbital geometry. Less satellites are visible at high latitudes. Several approaches are used to attain this apparent rapid response. Parallel searching speeds the search process materially. The Ground Operations Control Center (GOCC) is also involved in speed up of the search process. The search times shown in Figure 4-2 apply if the pilot frequency is known. The GOCC can help by assigning the pilot frequencies near the center of the band in a given geographical area. This basically collapses the search frequency dimension shown in Figure 4-1 to the uncertainty due to Doppler. Summary: This means that if the User Terminal stays in its home gateway area the acquisition process can be very quick. If the pilot frequency is unknown due either to poor assignment by the GOCC or due to the User Terminal roaming to another gateway area, the search time can extend. Basically the maximum search time is the number of pilots that must be searched times the time to acquire as shown in Figure 4-2. The mean time to acquire is roughly half of the maximum time to acquire. 4-4 Description of a Globalstar Gateway GS-TR-94-0001 Revision E 4.5 Forward CDMA Channel An example assignment of the code channels transmitted by a gateway is shown in Figure 4-3. Out of the 128 code channels available for use, the example depicts the Pilot Channel (always required), one Sync Channel, seven Paging Channels (the maximum number allowed), and 119 Traffic Channels of Rate Set 1. Another possible configuration could replace all the Paging Channels and the Sync Channel one for one with Traffic Channels of Rate Set 1, for a maximum of one Pilot Channel, zero Paging Channels, zero Sync Channels, and 127 Traffic Channels of Rate Set 1. FORWARD CDMA CHA NNEL

( 1.23 MHz channel transmitted by gateway) Pilot Chan Sync Chan Paging Ch 1 Up to Paging Ch 7 Traffic Ch 1 Traffic Ch N Up to Traffic Ch 119 Traffic Data Power Control Sub-Channel Figure 4-3 Forward CDMA Channel Transmitted by a Gateway The forward CDMA channel consists of the Pilot Channel, one Sync Channel, up to seven Paging Channels, and a number of Forward Traffic Channels. Multiple Forward Channels are used in a frequency. Gateway Forward different Channel placing each by on a 1 2 3 4 5 6 7 8 9 10 11 12 4-5 Description of the Globalstar System GS-TR-94-0001 Revision E 1 The forward link Pilot, Sync and Paging Channel is generated as shown in Figure 4-4. Walsh Funct ion 0 or 1 PN Chip, 1.2288 Mc ps Walsh Function 32 or 33 PN Chip, 1.2288 Mcps Walsh Funct ion p PN Chip, 1.2288 Mcps A A A Pilot Channel

( All 0's) Sync Channel Bits 1.2 kbps Convolutional Encoder r=1/2 K=9 Code Symbol 2.4 ksps Symbol Repetition Modulation Symbol 4.8 ksps Block Interleav er Modulation Symbol 4.8 ksps Paging Channel Bits 4.8 kbps 2.4 kbps Convolutional Encoder r=1/2 K=9 Code Symbol 9.6 ksps 4.8 ksps Symbol Repetition Long Code Mas k for Paging Channel k Modulation Symbol 9.6 ksps Block Interleav er Modulation Symbol 9.6 ksps 9.6 ksps Long Code Ge nerator 1.2288 Mcps Decimator Figure 4-4 Forward Link Pilot, Sync and Paging Channel The forward link is modulated as follows. Pilot Channel: The Pilot Channel is transmitted continuously by the Gateway and is utilized by the User Terminals operating within the coverage area of the Gateway to acquire timing on the forward channel, to provide a phase reference for coherent demodulation and to provide signal strength comparisons that govern when to do hand offs. The Pilot channel will generate an all zeros Walsh Code. This is combined with the short code used to separate signals from different Gateways and different satellites. The pilot channel is modulo 2 added to the 1.2288 Mc/s short code and is then QPSK spread across the 1.23 MHz CDMA bandwidth. The User Terminal monitors the pilot channel and assesses its signal strength at all times except when it is operating in the slotted mode. Sync channel: The Sync Channel is an encoded, interleaved, spread and modulated spread spectrum signal that is used by the User Terminals operating within the gateway coverage area to acquire initial time synchronization. The Sync channel will generate a 1200 b/s data stream that includes (1) time, (2) transmitting Gateway identification, (3) assigned paging channel. This is convolutionally encoded and Block Interleaved to combat fast fades. The resulting 4800 symbols per second data stream is modulo two added to the sync Walsh code at 1.2288 Mc/s and the short code. It is then QPSK spread across the 1.23 MHz CDMA bandwidth. 4-6 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Description of a Globalstar Gateway GS-TR-94-0001 Revision E Paging Channel: The Paging Channel is used for transmission of control information and pages from a gateway to a user terminal. The paging channel is convolutionally encoded at Rate = 1/2, Constraint length K = 9 and block interleaved. The resulting symbol rate is combined with the long code. The paging channel and the long code are modulo two added and provided to the symbol cover where the resulting signal is modulo two added to the 1.2288 Mc/s Walsh Code and the short code. The results are then QPSK spread across the 1.23 MHz CDMA bandwidth. Forward Traffic Channel: The Forward Link Traffic Channel - Rate Set 1 is generated as shown in Figure 4-5. Forward Traffic Channel Information Bits for User i with Rate Set 1

( 79, 32 , or 0 bits/f rame) 3.95 kbps 1.6 kbps 0 kbps Add Reserved Bit (1, 1, or 0 bits/f rame) Add Frame Quality Indica-tors ( 8 , 7, or 0 bits/frame) 4.0 kbps 1.65 kbps 0 kbps Add 8-bit Encoder Tail 4.4 kbps 2.0 kbps 0 kbps 4.8 kbps 2.4 kbps 0 kbps Convolutional Encoder r=1 /2 K=9 Code Symbol 9.6 ksps 4.8 ksps 0 ksps Symbol Repetition Modulation Symbol 9.6 ksps 0 ksps Block Interleaver Modulation Symbol 9.6 ksps 0 ksps 50 bps Power Control Bits Walsh Function j PN Chip, 1.228 8 Mcps MUX A 9.6 ksps 50 Hz Long Code Mask for User i Long Code Generator 1 .2288 Mcps Decimator Decimator Figure 4-5 Forward Link Traffic Channel - Rate Set 1 1 2 3 4 5 6 7 8 9 10 4-7 Description of the Globalstar System GS-TR-94-0001 Revision E 1 The Forward Link Traffic Channel - Rate Set 2 is generated as shown in Figure 4-6. Forward Traffic Channe l Information Bits for User m with Rate Set 2

(171, 79, 32, or 0 bits/frame) Add Reserv ed Bit ( 1, 1, 1, o r 0 bits/frame ) Add Frame Quality Indic ators ( 12, 8 , 7, or 0 bits /frame) Add 8-bi t Encode r Tail 9.6 kbps 4.8 kbps 2.4 kbps 0 kbps 9.2 kbps 4.4 kbps 2.0 kbps 0 kbps 8.6 kbps 4.0 kbps 1.65 kbps 0 kbps 8.55 kbps 3.95 kbps 1.6 kbps 0 kbps Convolut ional Encoder r=1/2 K=9 Code Symbol 19.2 ksps 9.6 ksps 4.8 ksps 0 ksps Symbol Repet ition Modulation Symbol 19.2 ksps 0 ksps Block Interleaver Modulatio n Symbol 19.2 ksps 0 ksps 50 bps Po wer Control Bits Walsh Funct ion n PN Chip, 1.2288 Mcps MUX A 19.2 ksps 50 Hz Long Code Mask for User m Long Code Generator 1.2288 Mcps Dec imator Dec imator Figure 4-6 Forward Link Traffic Channel - Rate Set 2 The Vocoder encodes the voice into a PCM data stream. The data stream is the processed as shown in Figure 4-5. The resulting data stream is then power controlled and modulo two added to the 1.2288 Mc/s Walsh code and the short code. The results is then QPSK Spread across the 1.23 MHz CDMA communication channel bandwidth. The Globalstar Air Interface will support two different rate sets from the Gateway. Within a rate set, the Globalstar Air Interface (GAI) will support variable data rate operation. When the high rate shown in Figure 4-5 is used, two Walsh codes are required. 2 3 4 5 6 7 8 9 4-8 Description of a Globalstar Gateway GS-TR-94-0001 Revision E 1 Modulation and Spreading: Modulation and spreading is applied as shown in Figure 4-7. I-Channel Inne r PN Se quence 1 .228 8 Mc ps A Outer PN Seq uence Gene rat or Oute r PN Chip 1.2 kcps I Q Base band Filt er I( t ) Baseband Filter s ( t) cos

( 2 f ct) Q( t) sin

( 2 f ct) Q-Channe l Inner PN Se quence 1 .22 88 Mcps D 1 Outer PN Chip Delay

= 8 33.3 33 m s Figure 4-7 Forward Link Modulation and Spreading The spreading sequence structure for a given Globalstar CDMA channel is comprised of an inner PN sequence pair and a single outer PN sequence. The inner PN sequence has a chip rate of 1.2288 Mcps and a length of 1024, while the outer PN sequence has an outer chip rate of 1200 outer chips per second and a length of 288; the outer PN sequence modulates the inner PN sequence to produce the actual spreading sequence, lasting exactly 240 msec. Exactly one inner PN period is contained within a single outer PN chip. The spreading and modulation process applies to all forward link channels. Path Identification: It is necessary to know the path that a signal has taken in order to facilitate gateway sharing of a forward CDMA channel and to support diversity combining. Path information is derived from the pilot signal. Gateway: Two gateways can share a forward CDMA channel. Pilot channel 0 is assigned to the first gateway can be allocated more power and serve as a beacon pilot within the beam to increase acquisition speed of the User Terminals in the beam. Orbital Plane: The inner PN sequence is used to identify the orbital plane. The length of the sequence is 2 10 chips at a chip rate of 1.2288 mcps. there are 24 repetitions every 20 ms. Satellite: Each satellite is identified by a pilot PN sequence. Beam: Each Satellite Beam has a unique outer PN sequence offset. 4-9 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Description of the Globalstar System GS-TR-94-0001 Revision E Beam Juxtaposition: Each Adjacent beam within a satellite is identified by a unique inner PN sequence offset. Inner PN offsets are reused among non adjacent beams of a satellite. Sharing of Forward CDMA Channel: It is also possible for two gateways to share a single subbeam. This mode is used when a gateways traffic needs only a fraction of a subbeam and each gateway must supply a separate pilot. In particular, this mode is useful when a satellite beam is moving from gateway service area A to gateway service area B. Gateways A and B can then share a subbeam as the traffic from A is ramping down and the traffic from B is ramping up. When sharing the first gateway will use all even-numbered code channels, and the second gateway will use all odd-numbered code channels. The Pilot Channel of the first gateway is transmitted on code channel 0. The Sync Channel associated with this Pilot Channel, if it exists, is transmitted on code channel 32. The Primary Paging Channel

(Paging Channel number 1) of the first gateway, if it exists, is transmitted on code channel 64. Paging Channel numbers 2, 3, 4, 5, 6, and 7, if they exist, are transmitted on code channels 2, 66, 4, 68, 6, and 70, respectively. The Pilot Channel of the second gateway is transmitted on code channel 1. The Sync Channel associated with this Pilot Channel, if it exists, is transmitted on code channel 33. The Primary Paging Channel (Paging Channel number 1) of the second gateway, if it exists, is transmitted on code channel 65. Paging Channel numbers 2, 3, 4, 5, 6, and 7, if they exist, are transmitted on code channels 3, 67, 5, 69, 7, and 71, respectively. 4.6 Return Link CDMA Channel The Reverse CDMA Channel is composed of Access Channels and Reverse Traffic Channels as shown in Figure 4-8. REVERSE CDMA CHANNEL

( 1.23 MHz channel received by g ateway) Access Ch Traf fic Ch 1 Traffic Ch m Figure 4-8. Reverse CDMA Channels Received at a Gateway 4-10 Description of a Globalstar Gateway GS-TR-94-0001 Revision E Figure 4-8 shows an example of all of the signals received by a gateway on the Reverse CDMA Channel. These channels share the same CDMA frequency assignment using direct-sequence CDMA. Each Traffic Channel is identified by a distinct user long code sequence. Each Access Channel is identified by its quadrature spreading codes and the gateway identification in the long code mask. Multiple Reverse CDMA Channels on different frequencies may be used by a gateway. The Reverse CDMA Channel has the overall structure shown in Figure 4-9 and Figure 4-10. Data transmitted on the Reverse CDMA Channel is grouped into 20 ms frames. All data transmitted on the Reverse CDMA Channel is convolutionally encoded, block interleaved, modulated by the 64-ary orthogonal modulation, and direct-sequence spread prior to transmission. Access Channel: The Access Channel is used by the User Terminal for communicating to the Gateway. It is used for short signaling message exchanges such as call origination, response to pages, and registrations. The Access channel is a slotted random access channel. Each Access Channel, as shown in Figure 4-9, is identified by a distinct Access Channel long code sequence. Acce ss Channel Information Bits

( 88 bits/frame) Add 8 bit Encoder Tail Convolutional Encoder r= 1/2 K=9 4.8 kbps 4.4 kbps Code Symbol 9.6 ksps Block Inte rle aver Code Symbol 9.6 ksps 64- ary Orthogonal Modulator Modulation Symbol

( Walsh chip) I-channel Se quence 1.2 288 Mcps 1.6 ksps ( 102.4 kcps) I Baseband Filter I( t) 1/2 PN chip Delay = 406 .9 ns Q D cos( 2 p fct) SS s( t) Baseband Filte r Q( t) sin( 2 p fc t) Q-channel Sequence 1 .2288 Mcps Figure 4-9 Return Link Access Channel PN chip 1.228 8 Mcps Long Code Generator Long Code Mask 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 4-11 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 Return Link Traffic Channel: Each Traffic Channel is identified by a distinct user long code sequence as shown in Figure 4-10. Reverse Traffic Cha nnel Informat ion Bits

( 171, 79, 32, or 0 bits/frame) Add Power Control Bit fo r 9.6, 4.8 &

2.4 kbps Add Frame Quality Indic ators for 9.6, 4.8 & 2 .4 kbps A dd 8 bit Encoder Tail 9.2 kbps 4.4 kbps 2.0 kbps 0 kbps 9.6 kbps 4.8 kbps 2.4 kbps 0 kbps 8.6 kbps 4.0 kbps 1.65 kbps 0 kbps 8.55 kbps 3.95 kbps 1.6 kbps 0 kbps Convolutional Enco der r=1/2 K=9 Code Symbol Block Interleaver Code Symbol 19.2 ksps 9.6 ksps 4.8 ksps 0 ksps I-channe l Sequence 1.2288 Mcps I Baseband Filter I( t) PN chip 1.2288 Mcps 1/2 PN chip Delay = 406.9 ns Q D Q-channel Seque nce 1.2288 Mcps co s( 2 p fct) SS s( t) Baseband Filt er Q( t) sin( 2 p fc t) Power Control Bit for 0 kbps Frame Modulation Symbol

( Walsh chip) 3.2 ksps

( 204.8 kcps) 1.6 ksps

( 102.4 kcps) 0.8 ksps

( 51.2 kcps) 0.2 ksps

( 12.8 kcps) 64-ary Orthogonal Modulat or Long Code Generator Long Code Mask Figure 4-10 Return Link Traffic Channel The rate 1/2 code used for the Globalstar return link takes advantage of longer coherence times for the channel and will perform better in the Additive White Gaussian Noise (AWGN) channel typical of Globalstar. The rate 1/3 code, typically used in terrestrial CDMA, performs better in a Rayleigh channel because it offers greater diversity. The return link does not use the randomizer used in cellular CDMA. It uses a continuous transmission with code symbol repetition to maintain the same rate. 4.7 CDMA End to End Performance There are a number of other CDMA topics that span both the forward and return links. Time: All gateway digital transmissions are referenced to a common CDMA system-wide time scale that uses the Global Positioning System (GPS) time scale, which is traceable to and synchronous with Universal Coordinated Time (UTC). GPS and UTC differ by an integer number of seconds, specifically the number of leap second corrections added to UTC since January 6, 1980. The start of CDMA System Time is January 6, 1980 00:00:00 UTC, which coincides with the start of GPS time. System Time keeps track of leap second corrections to UTC but does not use these corrections for physical adjustments to the System Time clocks. When receiving the paging channel, the User Terminal is within 1.0 microseconds of the earliest arriving signal used for demodulation. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 4-12 1 2 3 4 5 6 7 8 9 10 11 12 Description of a Globalstar Gateway GS-TR-94-0001 Revision E Link Delay: Delay through a link is an important end to end parameter. It becomes particularly important in conversations when one party attempts to interrupt the other. The LEO orbit satellites will provide a much more benign delay than the more common synchronous orbit satellites. Delay is held to 150 ms in each direction. There is a design margin, of course. Figure 4-11 summarizes the delay for the forward link. GTS CIS SBS User Terminal Modulator Card Distribute MSSL Queue &

Transmit HDLC Consolidate ATM MSSL Queue &

Transmit Sample &

Vocoder Encode 18 ms 43.4 ms 3.25 ms 5 ms 1 ms 0.5 ms 69 ms Figure 4-11 Forward Link Delay Budget Figure 4-12 illustrates the delay budget for the return link. GTS CIS SBS User Terminal Demodulator Card Distribute MSSL Queue &

Transmit HDLC Consolidate ATM MSSL Queue &

Transmit Select &

Vocoder Decode 69.5 ms 43.4 ms 15 ms 3.5 ms 1 ms 0.5 ms 3.5 ms Figure 4-12 Reverse Link Delay Budget Tradeoffs are possible to improve voice quality, improve capacity or other system level parameters at the expense of end to end delay. 4-13 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Description of the Globalstar System GS-TR-94-0001 Revision E Vocoder: The Globalstar vocoder is uses a Code Excited Linear Prediction (CELP) algorithm with a structure similar to that used by the IS-96 coder but with several improvements. The percentage of time between rates of 0 b/s and 8,550 can be adjusted. Voice quality can be traded for capacity. Voice quality can also be traded for signal delay. The Globalstar design will operate with high voice quality when the capacity is not stressed and when the links can be closed. If the links cannot be closed or if the capacity is being stressed, voice quality can be sacrificed. Vocoder rates and resulting channel rates are shown in Table 4-1. Table 4-1 Vocoder and Channel Rates Configuration Vocoder Rate Channel Rate Purposes Rate 1 Rate 1/2 Rate 1/4 Rate 1/8 8,550 3,950 1,750 800 9,600 4,800 2,400 1,200 High Quality Option Baseline Voiced Baseline Unvoiced Baseline Pauses/Background Some improvements are envisioned that may increase capacity. In the forward direction, a zero rate can be used. Since this is the coherent direction, the User Terminals can stay locked on by using the pilot. This is the direction that constrains capacity. In the return direction, some energy must be transmitted to keep the receiver locked since the return direction is not coherent. Power Control: The objective of power control is to transmit the minimum power necessary in order to achieve a given quality of service. Quality of service could be specified in terms of the Frame Error Rate (FER) and the probability of outage. Accurate power control reduces the transmit power needed to achieve a given quality of service objective, thereby prolonging battery life of portable phones. In addition, it also enhances capacity. Figure 4-13 is a simplified end to end diagram to support the description of power control. Phone Channel Gateway B B Reverse Link Correlation Forward Link rx tx A Transmit Gain Setting: Power Control Algorithm Segment Transmit Path A tx rx A B Figure 4-13 Power Control Simplified Diagram Power Control and time to acquire are intimately related as shown in Figure 4-14. 4-14 Description of a Globalstar Gateway GS-TR-94-0001 Revision E 95% Time Mean Time 90 80 70 60 50 40 30 20 10 0

-20

-18

-16

-14

-12

-10 Ec/Io (dB) 1 2 3 4 5 6 7 Figure 4-14 Acquisition Time as a function of Eb/No Once the target for Eb/No is established, the task of power control is to maintain the desired Eb/No. Acquisition time will extend if the Eb/No is not well established correctly or controlled to the desired value. In order to achieve the power control there are two loops. Inner Loop: The inner loop controls to the target Eb/No on a one bit per frame basis. Outer Loop: The outer loop adjusts the target Eb/No based on the measured Frame Error Rate. 4-15 Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 4-16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Description of the Globalstar System GS-TR-94-0001 Revision E 5. TERRESTRIAL INTERFACE 5.1 Telecommunication Network Interface The Gateway Architecture emphasizing the terrestrial interface is shown in Figure 5-1. GOCC SPCCs GMS Q Interface IS-41 CCP/VLR SSA CDMA S ubsystem

(GTS/TFU/CIS/

SBS/GC) BSCI A1 Interface(s) GSM GSM MSC/VLR GSM MS C/VLR MS C/V LR BSS Gateway IS-41 HLR IS-41 MAP T1/E1 - ISUP/MF-R2 T1/E1 - ISUP/MF-R2 GSM MAP GSM HLR GSM HLR GSM HLR PSTN OMC/SPCC Figure 5-1 Gateway Architecture The Gateway can operate in territories with terrestrial systems which are predominately GSM based or IS-41 C based. GSM: In a GSM environment, the GSM-MSC can either be incorporated in the Gateway or it can be external. If external, it can be directly associated with the Gateway or shared with other terrestrial cellular systems. A protocol conversion process may be required to support IS-41 roamers whose home networks use ANSI SS-7 for MAP signaling rather than ITU SS-7. Protocol conversion may be performed by the international SS-7 carrier or by a separate device. GSM roamers whose home networks comply with ITU SS-7 do not require protocol conversion support. IS-41: In an IS-41 network, a GSM-MSC must be available to provide GSM roaming services. The switch can either be in the gateway or can be back hauled to a GSM-MSC in another location. 5-1 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Protocol conversion may be required to convert between ITU SS-7 and ANSI SS-7 for mobility signaling to support international roamers with different home signaling protocols. Flexible Interface: In areas where there is no infrastructure or where there is an infrastructure other than GSM or IS-41, the Gateway can interface directly to the PSTN. The Gateway has a built in switch than can be adapted to a variety of PSTNs. This, of course, does not address type qualification which may or may not be a large problem depending on the specific country and situation involved. The entities associated with the terrestrial network of primary interest include:

GSM MSC/VLR: The GSM Mobile Switching Center (MSC) and Visitor Location Register (VLR) provide the call control and mobility management functions for GSM based users in the GW coverage area. The GSM MSC terminates one end of the A1 Interface, processing the BSSMAP and DTAP messages carried on this interface. The GSM VLR maintains the subscriber records for GSM based UTs operating on the GW. In addition, the GSM VLR interfaces to the existing GSM terrestrial cellular mobile Home Location Register (HLR) network. The GSM MSC also provides an interface to the local PSTN via standard signaling protocols (ISUP, MF-R1, MF-R2, etc.). GSM HLR/AuC: The GSM HLRs that are accessible from the GW are new or existing terrestrial cellular HLRs in the GSM MAP network. These HLRs contain the home subscriber records for GSM based GW UT subscribers. IS-41 CCP/VLR/SSA: For IS-41 based users in the GW, the IS-41 based call control and mobility management functions are processed by the IS-41 CCP/VLR/SSA entity. The IS-41 VLR maintains the subscriber records for IS-41 based UTs operating on the GW. In addition, the VLR interfaces to the existing IS-41 terrestrial cellular mobile Home Location Register (HLR) network. The SSA interfaces the GW to the local PSTN via standard signaling protocols (ISUP, MF-R1, MF-R2, etc.). The GW can also be configured in such a manner where the SSA can directly interface to one or more of the GW GSM MSCs if desired. IS-41 HLR/AuC: The IS-41 HLRs that are accessible from the GW are existing terrestrial cellular HLRs in the IS-41 MAP network. These HLRs contain the home subscriber records for IS-41 based GW UT subscribers. The IS 41 C Authentication Center provides authentication for its IS-41 C based Globlastar Subscribers. 5-2 Description of the Globalstar System GS-TR-94-0001 Revision E 1 Figure 5-2 provides more details on what is inside the Globalstar Gateway. SOCC GOCC GDN GDN Router DGlobalstar SPCC 7

14 8 0 2 5

3 69 DIGITAL BY ROPI ABC GW Links E1 or T1 BCN MSSL Ethernet IFL TCU

(Telemetry & Command Unit) OPI GMS

(Gateway Management System) GSS

(Gateway Switching System) SPCC Router GM CDA TCU TCU TCU TCU T C U P a n e l FL SSPA U p C o n v e r t e r FL Cabinet FL Shelf 5/polarize/ant

(40) RHCP LHCP GCU SS C a r d s U p c o n v e r t e r M o d u l a t o r C a r d s GPS Rcvr TFU 12 1 11 10 9 8 7 56 2 3 4 GWRDB CCP VME Cage V M E Backplane VLR SS7 SS7 Server VME Cage BSCI SS7 T1 SSA P a t c h P a n e l NIS P a t c h P a n e l CSU P a t c h P a n e l 2 1 T1/E1 Trunks IS-41 HLR GSM HLR OMC VLR SS7 GSM MSC E 1 Trunks 3 PSTN Trunk Set Combinations

(most likely):

IS-41 territory:

GSM territory:

1 2 2 3 CIS

(DISCO) Router SBS SBS Shelf 1/96 calls C a r d s

1 2

) S e l e c t o r I C a r d n t e r f a c e GWC VME Cage GCS

(Gateway CDMA System) T1 VIP Globalstar D O FF O N 2 1 4 3 6 7 5

8 9 0 DIGITAL BY

RL LNA C o n v e r t e r D o w n RHCP LHCP TFU TFU Cabinet Cabinet

(2)

(2) S S p p l l i i t t t t e e r r s s Antennas

(up to 4) GRS

(Gateway RF System) GTS RL Receive Cabinets

(up to 13) C a r d s R e c e i v e r C a r d C o n t r o l l e r Digital Cabinets

(up to 13) C o m m o n C a r d D e m o d C a r d s 2 3 4 5 6 7 8 Figure 5-2 Gateway Connections to the PSTN - Flexible Interface Physical Interface: The Gateway will connect to telecommunications networks via standard T1/E1. This is accomplished by the Service Switching Adjunct (SSA) shown in the upper right of Figure 5.1-2. This is also called Service Switching Point (SSP) in intelligent networks. PSTN Interface Protocols: The Gateway provides an Integrated Service Digital Network (ISDN) interface and will connect to the PSTN via Primary Rate Interface (PRI). 5-3 Description of the Globalstar System GS-TR-94-0001 Revision E 5.2 Registration Process Registration is the process by which the User Terminal notifies the Gateway of its location, status, identification, User Terminal type, and paging slot being monitored. Under normal circumstances, the Globalstar Gateway only contains a Visitor Location Register which is used in conjunction with external GSM or IS-41 Home Location Registers. Registration with an external HLR will be supported through the Gateway VLR. Registration while roaming involves the exchange of information between system types (GSM to IS-41 or visa versa). The messages and procedures for exchange of authentication data with the AuC/HLR is currently being reviewed by TIA for inclusion in IS-41D, and is summarized in TSB-51, Cellular Radio Telecommunications Inter systems Operation: Authentication, Signaling Message Encryption and Voice Privacy. There are two registration processes that will be supported. User Terminal IS-95 Modified IS-95 Modified User ID ESN/MIN GSM/IMSI HLR IS-41 GSM VLR Globalstar Globalstar IS-41 HLR Registration: Figure 5-3 illustrates the process of registration of an IS-95 User Terminal within an IS-41 HLR. 2. Home sys tem SPC is determined from ESN /M IN 3. The visited Gateway sends a data message that includes the phone ESN/MIN to the HLR across the signaling network. 4. T he Cus tomer Pr ofile is sc anned for an ID match and the present GW address is updated in the HLR. Gatew ay Gateway (Visited) IS-41 M ap Data ANSI SS7 GAI Globals tar Air Interface CDM A Visitor Location Register

(VLR) IS-41 M AP messages ANSI SS7 Signaling Networ k Home Location Register ANSI SS7 IS-41 Map Data Notes:

ESN = Electronic Serial Number MIN = Mobile Identification Number SPC = Switching Point Code IMEI = International Mobi le Equipment Identi fi er Home Location Regis ter

(HLR) Authenticati on Center (Futur e) 6. A r ecord is created in the Visi tor Location Register (VLR) and stored with profile information. User is deregi stered on shutdown or REGC ANC from HLR IS 41 Authenticates Equipment 5. The subscr iber profi le is returned to the Gateway. User is der egis tered fr om previ ous VLR ( REGCANC ) Us er Ter mi nal

(Visiting) 1. Data M essage includes ESN /M IN or IMEI File: Reg IS-41 Rev: 10/ 14/95 Figure 5-3 Registration of a U.S. based User with an IS-41 HLR 5-4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 Description of the Globalstar System GS-TR-94-0001 Revision E If IMEI are used in the User Terminals, ESN will not be stored. ESN is computed from the IMEI. The IMEI also incorporates the type approval code. GSM HLR Registration: Here, all of the network components (MSC, HLR, VLR and AuC) should be able to communicate as in the normal system. The challenge is reduced to a protocol inter working task on the Gateway-VLR and Gateway-MSC interfaces, and transport of GSM authentication data to and from the SIM. Figure 5-4 illustrates the registration process. 2. Home system SPC is determined from the User ID 3. The visited Gateway sends a data message that includes the User ID to the HLR across the signaling network. 4. The Customer Profile is scanned for a User ID match and the present location is updated in the Home Location Register (HLR). Gateway Gateway (Visited) GSM - MAP Data ITU C 7 GAI Globalstar Air Interface CDMA GSM-A Visitor Location Register

(VLR) MSC Mobile Switching Center GSM MAP messages ITU C 7 Signaling Network Notes:

MAP = Mobile Application Protocol SPC = Switching Point Code ID = Identification Home Location Register ITU C 7 GSM - MAP Data Home Location Register

(HLR) Kc Triplet Authentication Center The subscriber profile is returned to the Gateway. User is deregistered from previous VLR. 5. SIM Card Visiting GSM User Terminal 1. Data Messaage includes User ID File: Reg GSM Rev: 10/14/95 6. A record is created in the Visitor Location Register (VLR) and stored with profile information. User is deregistered on shutdown GSM Authenticates Subscriber Figure 5-4 Registration of a European User in a GSM HLR 5-5 Visiting User Terminal 1. Data Message includes ESN/MIN or IMEI File: Reg IS-41 GSM Rev: 10/14/95 1 2 Description of the Globalstar System GS-TR-94-0001 Revision E 2. Home system SPC is determined 3. The visited Gateway sends a data message that includes the phone ID to the HLR across the signaling network. 4. The Customer Profile is scanned for an ID match and the present GW address is updated in the HLR. Gateway Gateway (Visited) IS-41 MAP ITU SS-7 ITU C 7 GAI Globalstar Air Interface ITU-ANSI SS-7 Protocol Converter Home Location Register ANSI SS7 IS-41 MAP Data CDMA VLR Notes:

IS-41 Call Control Processor ESN = Electronic Serial Number MIN = Mobile Identification Number SPC = Switching Point Code ID = Identification (MIN & ESN) Home Location Register

(HLR) Authentication Center (Future) 6. A record is created in the Visitor Location Register (VLR) and stored with profile information. User is deregistered on shutdown or upon command from the HLR. 5. The subscriber profile is returned to the Gateway. User is deregistered from previous VLR. Figure 5-5 Registration of a U.S. User in a GSM Environment 5-6 Description of the Globalstar System GS-TR-94-0001 Revision E 2. Home system SPC is determined 3. The visited Gateway sends a data message that includes the User ID to the HLR across the signaling network. 4. The Customer Profile is scanned for an ID match and the present GW address is updated in the HLR. Gateway GAI Globalstar Air Interface Gateway (Visited) GSM - MAP Data ANSI SS7 CDMA GSM-A Visitor Location Register

(VLR) MSC Mobile Switching Center Notes:

SS-7 ANSI-ITU Protocol Converter ITU C 7 Home Location GSM - MAP Data Home Location Register

(HLR) S IM Ca rd Visiting GSM User Terminal 1. Data M essaage includes User ID Reg GS M I S -41 Rev: 10/ 14/9 5 MAP = Mobile Application Protocol Kc Tri plet SPC = Switching Point Code ID = Identification Authentication Center 6. A record is created in the Visitor Location Register (VLR) and stored with profile information. U ser is deregistered on shutdow n or upon command from the HLR GSM Authenticates Subscriber 5. The subscriber profile is returned to the Gateway. User is deregistered from previous VLR. Figure 5-6 Registration of a European User in an IS-41 Environment 5.3 Authentication Process Authentication verifies that the User Terminal is authorized to use the Globalstar resources. The Gateway will support authentication of the User Terminals; but, authentication is the responsibility of the home PLMN operator. The Gateway will transport authentication messages in the form required by the home PLMN operator. The Gateway will incorporate facilities to challenge, examine and update the authentication signature in the User Terminals. To achieve a consistent authentication scheme, the system adopted must be able to deal with each of the following situations:

a. GSM User in GSM System b. IS-41 User in IS-41 System c. GSM User in IS-41 System d. IS-41 User in GSM System Where IS-41 User indicates a user whose Home system is based upon the IS-41 model and protocols

(i.e. AMPS, IS-54, IS-95 and PSTN systems), and a GSM or IS-41 System indicates a serving 5-7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Description of the Globalstar System GS-TR-94-0001 Revision E Globalstar system where the mobility management facilities (HLR, VLR etc.) are GSM or IS-41-based, respectively. GSM User in GSM System: Here, all of the network components (MSC, HLR, VLR and AuC) should be able to communicate as in the standard GSM system. The challenge is reduced to a protocol inter working task on the Gateway-VLR and Gateway-MSC interfaces, and transport of GSM authentication data to and from the SIM. GSM roamers do not require a protocol converter. GSM uses the same SS-7 as the international signaling. IS-95 user in IS-95 (IS-41) System: All of the network components and protocols will operate in an IS-41 system. IS-41D supports and authentication center. Some networks may not support authentication. GSM User in IS-95 (IS-41) System: In this scenario, the various network components belong to different systems, as summarized in the following table:

Component SIM Gateway/MSC VLR HLR/AuC System GSM IS-41 IS-41 GSM The task that needs to be solved in this scenario is the retrieval and storage of authentication data from the HLR/AuC. For example, the triplets could be both requested and stored by the Gateway and the RAND and SRES parameters carried on the air interface to/from the SIM. The general message exchange is illustrated in Figure 5-7:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 5-8 Description of the Globalstar System GS-TR-94-0001 Revision E SIM Subscriber Unit Gateway HLR/AuC Inser t Subscriber Data Authentication Challenge Authentication Challenge Response Send Parameters Authentication Challenge Send Parameters Response Authentication Challenge Response RAND SRES RAND SRES 1 2 3 4 5 6 7 8 9 10 11 12 File: GSM in IS41 Figure 5-7 Authentication for a GSM User in IS-41 System IS-95 User in GSM System: In this scenario, the various network components belong to different systems, as summarized in the following table:

Component User Terminal Gateway/MSC VLR HLR/AuC System IS-95/Globalstar GSM GSM IS-41 In the IS-41 system, authentication is done mainly by the Gateway, with updates to authentication parameters periodically being retrieved from the AuC. The Gateway just has to recognize that the user understands IS-41 authentication, and not GSM and process messages appropriately. The messages and procedures for exchange of authentication data with the AuC/HLR is currently being reviewed by TIA for inclusion in IS-41C, and is summarized in TSB-51, Cellular Radio Telecommunications Inter systems Operation: Authentication, Signaling Message Encryption and Voice Privacy. 5-9 1 2 3 4 5 6 7 Description of the Globalstar System GS-TR-94-0001 Revision E 5.4 GSM - A Interface in Globalstar The Globalstar Gateway will interface with and MSC in the GSM environment in much the same way that any base station interfaces with the MSC. Figure 5-8 illustrates a typical GSM DTAP on Mobile Terminated Calls. UT GW (BSS) GSM MSC CDMA Radio Processing Events Signalling Channel Request Request for Service Activates Encryption, Service Option at Selector Activates Traffic Voice Path UDT CR (PAGE RESP) DT1 (CPH MOD CMD) DT1 (CPH MOD COM) DT1 (SETUP) DT1 (CALL CONFIRM) DT1 (ASS REQ) DT1 (ASS COM) DT1 (ALERT) DT1 (CONNECT) DT1(CONNECT ACK) Stable 2-way Call Figure 5-8 GSM DTAP on Mobile Terminated Call Figure 5-9 Illustrates GSM DTAP on a typical mobile originated call in Globalstar. 5-10 Description of the Globalstar System GS-TR-94-0001 Revision E UT GW (BSS) GSM MSC CDMA Radio Processing Events Signalling C hannel Request R equest for Service &

Authentication Activates Encryption, Service Option at Selector Activates Traffic Voice Path CR (CM SERV REQ) CC (AUTH REQ ) DT1 (AUTH RESP) DT1 (CPH MOD CMD) DT1 (CPH MOD COM) DT1 (SETUP) DT1 (CALL PROCEED) DT1 (ASS REQ) DT1 (ASS CO M) DT1 (ALERT) DT1 (CONNECT) DT1(CONNECT ACK) Stable 2 -way Call Figure 5-9 GSM DTAP on Mobile Originated Call 1 2 3 5-11 Description of the Globalstar System GS-TR-94-0001 Revision E This page intentionally left blank. 1 2 5-12 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Description of the Globalstar System GS-TR-94-0001 Revision E 6. CALL PROCESSING 6.1 Call Processing between Globalstar and PLMN This section discusses call processing between Globalstar and other PLMN systems. In Globalstar all User Terminals are treated as roaming from their terrestrial PLMN home system. Globalstar Only User Terminals: There are a series of User Terminals that are Globalstar Only. In these cases the service provider will incorporate the Globalstar Only User Terminals in the local Home Location Register (HLR). This applies to GSM or IS-41 HLRs. The Gateway will treat Globalstar Only UTs as Roamers. No Existing HLRs: In areas where there is no existing HLR, Globalstar may set up an HLR and function as the Service Provider. Emergency Calls: Globalstar will comply with the regulations for delivery of emergency calls. Mobile Originated Call: Figure 6-1 illustrates how a mobile originated call is processed. Gateway CDMA VLR Switch or MSC Origination Request From User 1 2 ORIGREQ or igreq 3 4 File: UT Ori gin Call Establishment Figure 6-1 Mobile Originated Call The following steps are performed:

1. An Origination Request (ORIGREQ) is received from a User Terminal. 2. An Origination Request INVOKE is sent from the Gateway (GW) to the VLR. 6-1 Description of the Globalstar System GS-TR-94-0001 Revision E 3. The Mobile is currently registered in this Visitor Location Register (VLR). The VLR responds with the Origination Request RETURN RESULT parameters. 4. The call is established with the terrestrial system. Mobile Terminated: There are two scenarios for roaming call delivery. The first one is for a successful call (i.e. the user is idle). In the second case, the user is busy - this case is used to illustrate the possible invocation of a supplementary service such as Call Forward on Subscriber Busy. Roaming Call Delivery - Idle Case: Figure 6-2 illustrates a successful call connection. Originating System Serving System Switch or MSC call origination 1 8 GW VLR HLR VLR GW LOCREQ 2 ROUTREQ 3 ROUTREQ routreq 5 4 6 routreq [TLD N]

7 locreq [TLDN]

Call Setup Figure 6-2 Roaming Call Delivery - Successful The following steps are performed:

1. The switch attempts to deliver a call to the home Gateway of a mobile. In this scenario, the mobile is roaming, and so is not registered at the VLR of the home system. 2. The VLR sends a Locate Request (LOCREQ) INVOKE to the Home Location Register

(HLR) requesting the location of the mobile. 6-2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Description of the Globalstar System GS-TR-96-0021 Revision E 3. The HLR determines the serving system for the User Terminal and sends a Routing Request INVOKE to the serving VLR. 4. The VLR sends a Routing Request (ROUTREQ) INVOKE to the Gateway to request the allocation of a Temporary Local Directory Number (TLDN) for the mobile. 5. The Gateway allocates a TLDN and returns the result in a Routing Request RETURN RESULT. 6. The VLR returns this TLDN to the HLR in the Routing Request RETURN RESULT. 7. The HLR sends the TLDN to the originating VLR via Locate Request RETURN RESULT. 8. The Gateway forwards the call to the destination Gateway (using the TLDN) and call setup is initiated with the serving Gateway. Roaming Call Delivery - Busy Case: This scenario illustrates the case where the called number is busy in a roaming system. The message exchange would be similar if features such as call forwarding were activated. Figure 6-3 is a case where the called number is busy. Originating System Serving System Switch or MSC 1 call origination GW VLR HLR VLR GW LOC REQ 2 ROUTREQ 3 ROUTREQ 4 routreq 5 6 routreq [busy]

7 locr eq [busy]

busy 8 Figure 6-3 Roaming Call Delivery - Subscriber Busy 6-3 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 The following steps are performed:

1. The switch attempts to deliver a call to the home Gateway of a mobile. In this scenario, the mobile is roaming, and so is not registered at the VLR of the home system. 2. The VLR sends a Locate Request (LOCREQ) INVOKE to the HLR requesting the location of the mobile. 3. The HLR determines the serving system for the User Terminal and sends a Routing Request INVOKE to the serving VLR. 4. The VLR sends a Routing Request INVOKE to the Gateway to request the allocation of a Temporary Local Directory Number (TLDN) for the mobile. 6. The Gateway determines that the mobile is busy in another call and returns the result in a Routing Request RETURN RESULT. 6. The VLR returns this notification to the HLR in the Routing Request RETURN RESULT. 7. The HLR sends the result to the originating VLR via Locate Request RETURN RESULT, and the VLR forwards the result to the Gateway. 8. The Gateway returns a busy indication to the network. Note that in the case of other call setup failures e.g. if Call Forwarding has been activated, the same scenario applies in principle, but the indication contained within the messages are different. 6-4 Description of the Globalstar System GS-TR-96-0021 Revision E 6.2 TIA and ETSI Call Flow Examples This is an informative appendix which contains examples of call flows. The diagrams follow these conventions:

All messages are received without error Receipt of messages is not shown except in the handoff examples Acknowledgments are not shown Authentication procedures are not shown Encryption mode transitions are not shown 1 2 3 4 5 6 7 8 6-5 1 2 3 4 5 6 Description of the Globalstar System GS-TR-94-0001 Revision E User Terminal Detects user-initiated call Sends Origination Message Sets up Traffic Channel Receives N5m consecutive valid frames Begins sending the Traffic Channel preamble Begins transmitting null Traffic Channel data Sends Service Request Message for Service Option 1 Begins processing primary traffic in accordance with Service Option 1 Sends Service Connect Completion Message Optional Sends Origination Continuation Message Optional Applies ring back in audio path Optional Removes ring back from audio path

(User conversation)

Access Channel Paging Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel Reverse Traffic Channel Forward Traffic Channel Forward Traffic Channel

Gateway Sets up Traffic Channel Begins sending null Traffic Channel data Sends Channel Assignment Message Acquires the Reverse Traffic Channel Sends Gateway Acknowledgment Order Allocates resources for Service Option 1 Sends Service Connect Message Optional Optional Sends Alert With Information Message (ring back tone) Optional Sends Alert With Information Message (tones off)

(User conversation) Figure 6-4 Simple Call Flow, User Terminal Origination Example Using Service Option 1

(TIA Call Control Procedures)

(Part 1 of 2) 6-6 Description of the Globalstar System User Terminal Detects user-initiated call Sends Channel Request Message indicating call origination and service option requested Sets up Traffic Channel Receives N5m consecutive valid frames Begins sending the Traffic Channel preamble Begins transmitting null Traffic Channel data Sends ETSI Layer 3 Transport Message containing CC Setup message See the note below

GS-TR-96-0021 Revision E Gateway Access Channel Paging Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel

Sets up Traffic Channel Begins sending null Traffic Channel data Sends Channel Assignment Message Acquires the Reverse Traffic Channel Sends Gateway Acknowledgment Order Starts setting up a call Sends ETSI Layer 3 Transport Message containing CC Call-

Proceeding message Note: The gateway and the user terminal follow the call establishment procedures as defined in section 5.2.1 of Begins processing primary traffic in accordance with Service Option 1 Sends Service Connect Completion

Message

(User conversation) ETS 300 557, GSM 04.08. Forward Traffic Channel Reverse Traffic Channel

Sends Service Connect Message

(User conversation) 1 2 3 4 Figure 6-5 Simple Call Flow, User Terminal Origination Example Using Service Option 1

(ETSI Call Control Procedures)

(Part 2 of 2) 6-7 Description of the Globalstar System GS-TR-94-0001 Revision E User Terminal Sends Page Response Message Sets up Traffic Channel Receives N5m consecutive valid frames Begins sending the Traffic Channel preamble Begins transmitting null Traffic Channel data Allocates resources for Service Option 1 Sends Service Response Message accepting Service Option 1 Begins processing primary traffic in accordance with Service Option 1 Sends Service Connect Completion Message Starts ringing User answers call Stops ringing Sends Connect Order Begins sending primary traffic packets from the Service Option 1 application

(User conversation)

Paging Channel Access Channel Paging Channel Forward Traffic Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel

Gateway Sends General Page Message Sets up Traffic Channel Begins sending null Traffic Channel data Sends Channel Assignment Message Acquires the Reverse Traffic Channel Sends Gateway Acknowledgment Order Sends Service Request Message for Service Option 1 Sends Service Connect Message Sends Alert With Information Message (ring)

(User conversation) Figure 6-6. Simple Call Flow, User Terminal Termination Example Using Service Option 1 (TIA Call Control Procedures)

(Part 1 of 2) 1 2 3 4 5 6-8 Description of the Globalstar System GS-TR-96-0021 Revision E User Terminal Gateway Sends Channel Request Message indicating paging response Sets up Traffic Channel Receives N5m consecutive valid frames Begins sending the Traffic Channel preamble Begins transmitting null Traffic Channel data Sends ETSI Layer 3 Transport Message containing RR Paging Response message Starts alerting Sends ETSI Layer 3 Transport Message containing CC Call_Confirmed message

Paging Channel Access Channel Paging Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel

Sends General Page Message with service option requested Sets up Traffic Channel Begins sending null Traffic Channel data Sends Channel Assignment Message Acquires the Reverse Traffic Channel Sends Gateway Acknowledgment Order Sends ETSI Layer 3 Transport Message containing CC Setup message See note below Note: The gateway and the user terminal follow the call establishment procedures as defined in section 5.2.2 of Begins processing primary traffic in accordance with Service Option 1 Sends Service Connect Completion

Message

(User conversation) ETS 300 557, GSM 04.08. Forward Traffic Channel Reverse Traffic Channel

Sends Service Connect Message

(User conversation) Figure 6-7 Simple Call Flow, User Terminal Termination Example Using Service Option 1

(ETSI Call Control Procedures)

(Part 2 of 2) 1 2 3 4 6-9 1 2 3 4 5 6 7 8 9 Description of the Globalstar System GS-TR-94-0001 Revision E Gateway

Reverse Traffic Channel Forward Traffic Channel

Sends Release Order User Terminal Detects user-initiated disconnect Sends Release Order Enters the System Determination Substate of the User Terminal Initialization State Figure 6-8. Simple Call Flow, User Terminal Initiated Call Disconnect Example (TIA Call Control Procedures)

(Part 1 of 2) User Terminal Detects user-initiated disconnect Sends ETSI Layer 3 Transport Message containing CC Disconnect message Releases the MM connection Sends ETSI Layer 3 Transport Message containing CC Release Complete message1

Releases the RR connection (Traffic

Channel) Enters the System Determination Substate of the User Terminal Initialization State Gateway Initiates procedures to clear the network connection Sends ETSI Layer 3 Transport Message containing CC Release message Releases the MM connection Sends Release Order Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel

Figure 6-9 Simple Call Flow, User Terminal Initiated Call Disconnect Example (ETSI Call Control Procedure)

(Part 2 of 2) 1For more details see call release procedures defined in section 5.4.3 of ETS 300 557, GSM 04.08. 6-10 Description of the Globalstar System GS-TR-96-0021 Revision E User Terminal Sends Release Order Enters the System Determination Substate of the User Terminal Initialization State Gateway Detects call disconnect Sends Release Order

Forward Traffic Channel Reverse Traffic Channel

Figure 6-10. Simple Call Flow, Gateway Initiated Call Disconnect Example (TIA Call Control Procedures)

(Part 1 of 2) 1 2 3 4 5 6 7 8 6-11 Description of the Globalstar System GS-TR-94-0001 Revision E User Terminal Sends ETSI Layer 3 Transport Message containing CC Release message Releases the MM connection

Releases the RR connection (Traffic

Channel) Enters the System Determination Substate of the User Terminal Initialization State Gateway Detects call disconnect Sends ETSI Layer 3 Transport Message containing CC Disconnect message Releases the MM connection Sends ETSI Layer 3 Transport Message containing CC Release2 Complete message Sends Release Order Forward Traffic Channel Reverse Traffic Channel Forward Traffic Channel Forward Traffic Channel

Figure 6-11 Simple Call Flow, Gateway Initiated Call Disconnect Example (ETSI Call Control Procedure)

(Part 2 of 2) 1 2 3 4 5 6 2 For more details see the call release procedures as defined in section 5.4.4 of ETS 300 557, GSM 04.08. 6-12 Description of the Globalstar System GS-TR-96-0021 Revision E 1 2 3 4 User Terminal

(User conversation) Detects request for third party to be added to conversation Sends Flash With Information Message (dialed digits) Optional Applies ring back in audio path Optional Removes ring back tone from audio path

(Two-way conversation with added party; original party held) Detects user request to establish three-way conversation Sends Flash With Information Message

(Three-way conversation)

Gateway

(User conversation) Reverse Traffic Channel Forward Traffic Channel Forward Traffic Channel

Mutes speech Optional Sends Alert With Information Message (ring back tone)

(Called party answers) Optional Sends Alert With Information Message (tones off) Unmutes speech from added party

(Two-way conversation with added party; original party held) Reverse Traffic Channel

Reconnects original party

(Three-way conversation) Figure 6-12. Simple Call Flow, Three-Party Calling Example (TIA Call Control Procedures) 6-13 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 5 6 7 8 9 User Terminal Gateway

(User conversation with first party)

(User conversation with first party) Optional Applies call waiting tone in audio path Detects user request to change parties Sends Flash With Information Message

(User conversation with second party;

first party held) Detects user request to change parties Sends Flash With Information Message

(User conversation with first party;

second party held)

Forward Traffic Channel Reverse Traffic Channel Reverse Traffic Channel

Detects incoming call Optional Sends Alert With Information Message (call waiting tone) Mutes speech path to first party, connects second party

(User conversation with second party; first party held) Mutes speech path to second party, connects first party

(User conversation with first party;

second party held) Figure 6-13. Simple Call Flow, Call-Waiting Example (TIA Call Control Procedures) Figure 6-14 illustrates call processing operations during a soft handoff from pilot A to pilot B. Figure 6-

15 illustrates call processing operations during a sequential soft handoff in which the user terminal is transferred from a pair of pilots A and B through a pair of pilots A and C to pilot C. All the handoff call processing procedures described below are the same for both the TIA and the ETSI call control and mobility management procedures. 6-14 Description of the Globalstar System GS-TR-96-0021 Revision E 1 2 3 User Terminal

(User conversation using A) Sends Pilot Strength Measurement

Message Reverse Traffic Channel Receives Handoff Direction Message Acquires B; begins using Active Set {A,B}

Sends Handoff Completion Message Handoff drop timer of pilot A expires Sends Pilot Strength Measurement Message Receives Handoff Direction Message Stops diversity combining; begins using Active Set {B}

Sends Handoff Completion Message

Forward Traffic Channel Reverse Traffic Channel Reverse Traffic Channel Forward Traffic Channel Reverse Traffic Channel

(User conversation using B)

Gateway

(User conversation using A) Receives Pilot Strength Measurement Message GW decides to begin handoff to channel B. Begins transmitting traffic on the Forward Traffic Channel on B Sends Handoff Direction Message to use A and B Receives Handoff Completion Message Receives Pilot Strength Measurement Message GW decided to cancel channel A Sends Handoff Direction Message to use B only Receives Handoff Completion Message Stops transmitting on the Forward Traffic Channel using A

(User conversation using B) Figure 6-14. Call Processing During Soft Handoff 6-15 Description of the Globalstar System GS-TR-94-0001 Revision E 1 2 3 4 User Terminal

(User conversation using A and B) Gateway

(User conversation using A and B) Sends Pilot Strength Measurement

Reverse Traffic

Receives Pilot Strength Message Channel Receives Handoff Direction Message Stops diversity combining A and B;

starts diversity combining B and C Sends Handoff Completion Message Sends Pilot Strength Measurement Message

Forward Traffic Channel Reverse Traffic Channel Reverse Traffic Channel

Measurement Message, determines that new Active Set should contain B and C Begins transmitting traffic on the Forward Traffic Channel using C Sends Handoff Direction Message to use B and C Receives Handoff Completion Message Stops transmitting on the Forward Traffic Channel using A Receives Pilot Strength Measurement Message

(Continues)

(Continues) Figure 6-15. Call Processing During Sequential Soft Handoff

(Part 1 of 2) 6-16 Description of the Globalstar System GS-TR-96-0021 Revision E User Terminal

(Continues) Gateway

(Continues) Receives Handoff Direction Message Stops diversity combining; begins using Active Set {C}

Sends Handoff Completion Message

Forward Traffic Channel Reverse Traffic Channel

(User conversation using C) Sends Handoff Direction Message to use C only Receives Handoff Completion Message Stops transmitting on the Forward Traffic Channel using B

(User conversation using C) Figure 6-16 Call Processing During Sequential Soft Handoff

(Part 2 of 2) 1 2 3 4 5 6 7 8 9 6-17