SuperCom - PureOne Device Analysis and Design of Cellular/BLE Duty Cycle Contents Purpose ................................................................................................................................................... 2 Device details .......................................................................................................................................... 2 Device Tx Data Analysis ........................................................................................................................... 3 Cellular Data Tx Flow ............................................................................................................................... 3 Data payload analysis: ......................................................................................................................... 3 Standard Active Transmission Time .................................................................................................... 4 Description of reasonable and infrequent cases - Cellular ..................................................................... 4 Bluetooth duty cycle analysis .................................................................................................................. 5 Standard Active Transmission Time .................................................................................................... 5 Description of reasonable and infrequent cases ................................................................................ 5 System design to protect from duty cycle alterations. .......................................................................... 6 Standard design............................................................................................................................... 6 Design to meet and keep requirements: ........................................................................................ 6 Purpose
- Analyze and demonstrate the cellular and BLE Tx duty factor.
- Describe all reasonable and infrequent use cases.
Show how the design inherently provides protection from alterations of the maximum duty factor that was considered for compliance purposes. Device details Product:
Manufacturer:
Model:
Hardware Version:
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PureOne SuperCom LTD PureOne 3.0 2BAX3PRFPUREONE3 Device Tx Data Analysis Cellular Data Tx Flow
- Communication interval o Infrequent: every 60 minutes, usually when at home. o Frequent: every 10 minutes, usually when outside home.
- Communication session flow:
o Authentication and security o Data exchange o Session termination Data payload analysis:
Data payload is up to 2060 bytes per session, according to the following analysis:
o Authentication and security 600 bytes TLS/SSL negotiation: 200 bytes HTTP headers and structure: 180 bytes Protocol overhead data: 100 bytes Authentication net payload: 120 bytes o Data exchange 1100 bytes Security overhead 80 bytes HTTP headers and structure: 180 bytes Other overhead data: 100 bytes Data items size: 640 byes Single data item size: 32 bytes Protocol overhead data: 32 bytes Number of data items: 10 o Session termination 360 bytes Security overhead 80 bytes HTTP headers and structure: 180 bytes Protocol overhead data: 40 bytes Termination net payload: 60 bytes Standard Active Transmission Time BLE Tx schematics
2060 bytes payload in bits o 2060 X 8 = 16,480
- Data rate: assuming 5 Mbps (using LTE network connection)
- Calculation:
o 16,480 / 5 = 3.296 milliseconds The active transmission time is a time slot of 10 minutes is 3.296 milliseconds. Duty Cycle = (3.296 milliseconds / 600,000 milliseconds) * 100 = 0.05493%
The standard typical duty cycle is: 0.05493%
Description of reasonable and infrequent cases - Cellular There are 3 use cases:
1. Standard reporting. a. Device is active, not at home, communications is every 10 minutes. b. Duty cycle is 0.05493%
2. Infrequent reporting. a. Device is active, at home or static position/location, communications is every 60 minutes. b. Duty cycle is 0.00915%
3. Alarm reporting. a. A special case where a single alarm/data should be immediately sent. b. Maximum allowed alarms per day: 20 alarms Duty cycle at worst case scenario:
Assumptions:
Standard reporting mode is active all the time. o Communication is every 10 minutes. o Payload per session: 2060 bytes o Daily payload:
1440 minutes / 10 minutes X 2060 bytes Daily payload: 296,640 bytes
- Device is triggering 20 alarms per day. o Each alarm payload: 2060 bytes o Daily alarms payload: 2060 * 20 = 41,200 bytes Total daily payload: 296,640 + 41,200 = 337,840 bytes
Daily Payload in bits: 337,840 * 8 = 2,702,720 bits Tx time, assuming data rate of 5Mbps: 2,702,720 / 5 = 540,544 milliseconds Daily Duty Cycle = (540,544 milliseconds / 86,400,000 daily milliseconds) * 100 = 0.6267%
The maximum daily Tx duty cycle is 0.6267%. Bluetooth duty cycle analysis The PureOne device uses a Bluetooth low energy certified module. The device is set up to transmit status data every 5 seconds. The protocol is Advertising (broadcast) under GAP profile. Protocol characteristics:
- Data rate: 1 Mbps
Interval: 5 seconds
- Channels: All 3 channels used (channels: 37,38,39)
Payload: 39 bytes Standard Active Transmission Time Payload in bits: 39 (bytes) * 8 = 312 bits Daily packets: 86400 / 5 = 17,280 All 3 BLE channels: 17,280 * 3 = 51,840 51,880 / 1 (Mbps) = 51.88 milliseconds Duty cycle: 51.88 / 86,400,000 = 0.00006 %
The BLE duty cycle is 0.00006 %
Description of reasonable and infrequent cases The BLE advertising protocol uses a random time before/after each 5 seconds Tx interval. The average of 5 seconds interval is still being kept. System design to protect from duty cycle alterations. Standard design The PureOne device is a hardware-based device. The hardware was designed, reviewed, implemented, and manufactured using standard design tool and by professional engineers. During manufacturing, each single device is being tested and documented for quality control. The radio hardware component are certified. During development process, intensive QA and external Labs are used for verifications. Design to meet and keep requirements:
To meet duty cycle requirements, and keep up with them:
- Device has a precise real time clock for timing. o Time is constantly being verified against a server to avoid any drift.
- Device has flash and eeprom memory to keep track of all communication intervals and data payload history.
- RF modules are certified and by know vendors.
Product is being tested at RF labs. Product is reporting its Tx statistics for analysis and record keeping.