Bluetooth Protocol Reference Model

Figure 6.5 shows a correspondence between the Bluetooth’s protocol stack
and the standard OSI stack. From Figure 6.5, we observe the existence of both Bluetooth-specific
protocols, like LMP and L2CAP, and non-Bluetooth-specific protocols like
PPP, IP, and TCS BIN. In Bluetooth, we can distinguish four groups of protocols
according to their purpose:
1. Bluetooth core protocols (baseband, LMP, L2CAP, and SDP): This
group consists of specific Bluetooth protocols developed by the
Bluetooth SIG.
2. Cable replacement protocol (RFCOMM): This one is constituted by
Bluetooth SIG but it is based on the ETSI TS 07.10.
3. Telephony protocol control specification (TCS BIN, AT-commands):
Also this one is constituted by Bluetooth SIG, but they are based
on the ITU-T Recommendation Q.931.
4. Adopted protocols (PPP, UDP/TCP/IP, WAP/WAE, OBEX, vCard,
vCal, and IrMC).
In addition, the specifications comprise a host controller interface (HCI),
which provides a command interface to the baseband controller, link manager
controller (LMC), and access to hardware status and control registers. In effect the Bluetooth core provides a common wireless system to various protocols,
included those in this list and other ones freely implemented by vendors,
which sometimes are interfaced with the core by a sort of convergence
layer represented by RFCOMM.