Bluetooth Low Energy Packet Format
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The document outlines the Bluetooth Low Energy (BLE) packet formats, including details on various types of packets such as advertising and data channel PDUs. It specifies the structure and content of packet headers, payloads, and CRC checks. Additionally, it covers specific advertising packet types like iBeacon and Eddystone beacons, as well as their corresponding data formats.
Bluetooth Low Energy Packet Format
- 1. Bluetooth Low Energy (BLE) Packet Format Winfred LU AMG GCSA STMicroelectronics
- 3. Link Layer Packet Format 1 byte 4 bytes 2 – 39 (33*) bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC Data Channel PDUAdvertising Channel PDU 2 bytes 6 – 37 bytes Header Payload 2 bytes 0 – 27 bytes 4 bytes Header Payload MIC* * 33 bytes for Data Channel PDUs w/o DPLE * MIC: Message Integrity Check (option) • Advertising Payload • Scan Request/Response Payload • Connection Request Payload • Link Layer Control Payload • Data Payload
- 5. Advertising Packet 1 byte 4 bytes ≤ 39 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes 6 – 37 bytes Header Advertising payload 6 bytes 0 – 31 bytes ADV Address Advertising Data AD0 AD … … ADn Advertising Channel PDU 0x8E89BED6 1 byte 1 byte AD Length (≤ 29 bytes) AD Length AD Type AD Data 4 bits 2 bits 1 bit 1 bit 6 bits 2 bits PDU type RFU TxAdd RxAdd Length RFU 0xAA 0 0000 ADV_IND 0001 ADV_DIRECT_IND 0010 ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110 ADV_SCAN_IND
- 6. Scan Request 1 byte 4 bytes ≤ 39 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes 12 bytes Header Scan Request payload 6 bytes 6 bytes Scanner Address Advertising Address Advertising Channel PDU 0x8E89BED6 4 bits 2 bits 1 bit 1 bit 6 bits 2 bits PDU type RFU TxAdd RxAdd Length RFU 0xAA 123 0000 ADV_IND 0001 ADV_DIRECT_IND 0010 ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110 ADV_SCAN_IND
- 7. Connection Request 1 byte 4 bytes ≤ 39 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes 34 bytes Header Connection Request payload 6 bytes 6 bytes 22 bytes Initiator Address Advertising Address Link Layer Data Advertising Channel PDU 0x8E89BED6 4 bits 2 bits 1 bit 1 bit 6 bits 2 bits PDU type RFU TxAdd RxAdd Length RFU 0xAA 5 34 4 bytes 3 bytes 1 byte 2 bytes 2 bytes 2 bytes 2 bytes 5 bytes 5 bits 3 bits AA CRCInit WinSize WinOffset Interval Latency Timeout ChM Hop SCA 5 - 16 for data channel PDUs 0000 ADV_IND 0001 ADV_DIRECT_IND 0010 ADV_NONCONN_IND 0011 SCAN_REQ 0100 SCAN_RSP 0101 CONNECT_REQ 0110 ADV_SCAN_IND
- 8. Advertising Packet : iBeacon 1 byte 4 bytes ≤ 39 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes 36 bytes Header Advertising payload 6 bytes 30 bytes ADV Address Advertising Data AD0 AD1 Advertising Channel PDU 0x8E89BED6 1 byte 1 byte 1 byte AD Length AD Type Flags 4 bits 2 bits 1 bit 1 bit 6 bits 2 bits PDU type RFU TxAdd RxAdd Length RFU 0xAA 0x02 0x01 0x06 1 byte 1 byte 2 bytes 1 byte 1 byte 16 bytes 2 bytes 2 bytes 1 byte AD Length AD Type Com. ID iBcn Type iBcn Length Proximity UUID Major Minor TX power 0x1A 0xFF 0x004C 0x02 0x15 Manufacturer specific Apple, Inc. b0: limited discoverable b1: general discoverable b2: BR/EDR supported b3: BR/EDR controller b4: BR/EDR host Proximity beacon Tx Power • at 1 m for iBeacon • at 0 m for Eddystone
- 9. Advertising Packet : Eddystone Beacon 1 byte 4 bytes ≤ 39 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes ≤ 37 bytes Header Advertising payload 6 bytes ≤ 31 bytes ADV Address Advertising Data AD0 AD1 AD2 Advertising Channel PDU 0x8E89BED6 1 byte 1 byte 1 byte AD Length AD Type Flags 4 bits 2 bits 1 bit 1 bit 6 bits 2 bits PDU type RFU TxAdd RxAdd Length RFU 0xAA 0x02 0x01 0x06 1 byte 1 byte 2 bytes ≤ 20 bytes AD Length AD Type Eddystone UUID Eddystone Frame 1 byte 1 byte 2 bytes AD Length AD Type Eddystone UUID 0x03 0x03 0xFEAA • UID frame • URL frame • TLM frame 0x16 0xFEAA
- 10. Eddystone Beacon Cont. 6 bytes ≤ 31 bytes ADV Address Advertising Data AD0 AD1 AD2 1 byte 1 byte 1 byte AD Length AD Type Flags 0x02 0x01 0x06 1 byte 1 byte 2 bytes ≤ 20 bytes AD Length AD Type Eddystone UUID Eddystone Frame 1 byte 1 byte 2 bytes AD Length AD Type Eddystone UUID 0x03 0x03 0xFEAA 0x16 0xFEAA 1 byte 1 byte 2 bytes 2 bytes 4 bytes 4 bytes Frame Type Version Battery Voltage Beacon Temp Adv PDU Count since boot Time since boot 1 byte 1 byte 1 byte 0 – 17 bytes Frame Type Tx Power URL Schem Encoded URL 1 byte 1 byte 10 bytes 6 bytes 2 bytes Frame Type Tx Power Namespace ID Instance ID RFU 0x00 0x10 0x20 0x00 UID frame URL frame TLM frame Tx Power • at 1 m for iBeacon • at 0 m for Eddystone Not covered: • EID frame • Type = 0x30 • Encrypted TLM • Version = 0x01
- 12. Link Layer Control Packet 1 byte 4 bytes 2 – 29 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC Data Channel PDU 2 bytes 0 – 27 bytes Header Data payload 2 bits 1 bit 1 bit 1 bit 3 bits 8 bits LLID NESN SN MD RFU Length 0xAA 0~ or 0x55 1~ 01: LL Data PDU – Continuation or Empty 10: LL Data PDU – Start of message 11: LL Control PDU 3 1 byte 0 – 26 bytes Opcode Control Data 0x00: LL_CONNECTION_UPDATE_IND 0x01: LL_CHANNEL_MAP_IND 0x02: LL_TERMINATE_IND ……: Refer to Spec 6,B,2.4.2
- 13. Data Packet 1 byte 4 bytes 2 – 257 (33*) bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bytes ≤ 251 (27*) bytes Header Data payload * 39,33,27,23: without DPLE * MIC: Message Integrity Check 4 bytes ≤ 247 (23*) bytes ≤ 251 (27*) w/o MIC L2CAP Header 1 byte ≤ 246 (22*) bytes ≤ 250 (26*) w/o MIC Opcode Data L2CAP protocol PDU Data Channel PDU ATT protocol PDU 0xAA 0~ or 0x55 1~ 4 bytes MIC*
- 14. LE Data Packet Length Extension (DPLE) 1 byte 4 bytes 2 – 257 (33*) bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 2 bits 1 bit 1 bit 1 bit 3 bits 5 bits 3 bits LLID NESN SN MD RFU Length RFU Data Channel PDU 2 bytes ≤ 255 (31*) bytes Header Data payload, including optional MIC 2 bits 1 bit 1 bit 1 bit 3 bits 8 bits LLID NESN SN MD RFU Length Core Spec 4.1 • Max length = 11111b = 31 Core Spec 4.2 • Max length = 11111111b = 255 0xAA 0~ or 0x55 1~ 01: LL Data PDU – Continuation or Empty 10: LL Data PDU – Start of message 11: LL Control PDU * 33, 31: without DPLE
- 15. L2CAP Fragmentations (w/o DPLE) 1 byte 4 bytes ≤ 33 bytes 3 bytes Preamble Access Address Protocol Data Unit (PDU) CRC 0xAA 0~ or 0x55 1~ 2 bytes ≤ 27 bytes Header Data payloadData Channel PDU 4 bytes MIC* 4 bytes 23 bytes L2CAP Header ATT protocol PDU 27 bytes ATT protocol PDU L2CAP protocol PDU 27 bytes or less ATT protocol PDU …….. Fragment 1 Fragment 2 Fragment n 2 bytes 2 bytes Length Channel IDL2CAP Header ≤ ATT_MTU (up to 512)
- 16. Attribute (ATT) Protocol PDU 1 byte ≤ ATT_MTU - 1 Opcode Data ATT protocol PDU Attribute Parameters 12 bytes Authentication Signature 2 bytes 2 or 16 bytes variable length implementation specific Attribute Handle Attribute Type Attribute Value Attribute Permissions 1 0x2800 0x1801 Read 2 0x2803 20 03 00 05 2a Read … …
- 17. Thank you