Bluetooth PAN Basics
Packet Format
13 | P a g e
Chapter 9: Packet Format
For a pair of communicating Bluetooth devices, the master always starts transmission at even
numbered slots, while slave initiates only at odd numbered slots. A single packet is transmitted in
each slot. A Bluetooth packet comprises of the following three fields:
A. Access Code:
This code is defined by the master and is unique for the piconet. It identifies the incoming
packets for the Bluetooth devices. If a packet header follows, the access code is 72 bits long;
otherwise the access code is 68 bits long and is known as a shortened access code.
B. Packet Header:
The 54-bit packet header contains information related to MAC addressing, flow control, HEC
(Header Error Correction) and ARQ.
C. Payload:
A variable length payload may trail the header and it contains the actual data.
Figure 8: Bluetooth Packet Format
docsity.com