Bluetooth WHITE PAPER
Bluetooth Protocol Architecture
Version 1.0
This white paper describes the protocol
architecture developed by the Bluetooth Special
Interest Group (SIG). Various usage models are
presented and complemented with a description
of the protocols relevant to their implementation.
RESPONSIBLE
DATE
N.B.
Aug 25th 99
Riku Mettala
E-MAIL ADDRESS
riku.mettala@nmp.nokia.com
STATUS
DOCUMENT NO.
1.C.120/1.0
Bluetooth Protocol Architecture Page 2 of 20
29 September 1999 2
Special Interest Group (SIG)
The following companies are represented in the Bluetooth Special Interest
Group:
Ericsson Mobile Communications AB
IBM Corp.
Intel Corp.
Nokia Mobile Phones
Toshiba Corp.
Contributors
Bisdikian, Chatschik
IBM Corporation
Bouet, Stephane
Nokia Mobile Phones
Inouye, Jon
Intel Corporation
Mettälä, Riku
Nokia Mobile Phones
Miller, Brent
IBM Corporation
Morley, Ken
3Com Corporation
Muller, Thomas
Nokia Mobile Phones
Roter, Martin
Nokia Mobile Phones
Slotboom, Erik
Ericsson Mobile Communications AB
Disclaimer and copyright notice
THIS DOCUMENT IS PROVIDED “AS IS” WITH NO WARRANTIES WHATSOEVER,
INCLUDING ANY WARRANTY OF MERCHANTABILITY, NONINFRINGEMENT, FITNESS
FOR ANY PARTICULAR PURPOSE, OR ANY WARRANTY OTHERWISE ARISING OUT OF
ANY PROPOSAL, SPECIFICATION OR SAMPLE. All liability, including liability for
infringement of any proprietary rights, relating to use of information in this document is
disclaimed.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights are
granted herein.
Copyright © Nokia Mobile Phones 1999.
*Third-party brands and names are the property of their respective owners.
Bluetooth Protocol Architecture Page 3 of 20
29 September 1999 3
Contents
1 Introduction ......................................................................................... 4
1.1 Bluetooth Protocol Stack............................................................. 4
2 Protocols in Bluetooth Architecture.................................................. 6
2.1 Bluetooth Core Protocols ............................................................ 7
2.1.1 Baseband....................................................................... 7
2.1.1.1 Audio................................................................ 7
2.1.2 Link Manager Protocol ................................................... 7
2.1.3 Logical Link Control and Adaptation Protocol................. 7
2.1.4 Service Discovery Protocol (SDP).................................. 8
2.2 Cable Replacement Protocol ...................................................... 8
2.2.1 RFCOMM ....................................................................... 8
2.3 Telephony Control Protocol......................................................... 8
2.3.1 Telephony Control – Binary............................................ 8
2.3.2 Telephony Control – AT Commands .............................. 8
2.4 Adopted Protocols....................................................................... 9
2.4.1 PPP................................................................................ 9
2.4.2 TCP/UDP/IP ................................................................... 9
2.4.3 OBEX Protocol ............................................................... 9
2.4.3.1 Content Formats ..............................................9
2.4.4 WAP............................................................................. 10
2.4.4.1 Content Formats ............................................11
3 Bluetooth Usage Models and Protocols ......................................... 12
3.1 File Transfer.............................................................................. 12
3.2 Internet Bridge .......................................................................... 12
3.3 LAN Access .............................................................................. 13
3.4 Synchronization ........................................................................ 14
3.5 Three-in-One Phone ................................................................. 14
3.6 Ultimate Headset ...................................................................... 15
4 Summary............................................................................................ 16
5 References......................................................................................... 17
6 Acronyms........................................................................................... 19
Bluetooth Protocol Architecture Page 4 of 20
Introduction 29 September 1999 4
1 Introduction
The Bluetooth Special Interest Group (SIG) has developed the Bluetooth
Specification Version 1.0 Draft Foundation (thereafter to be referred to as the
”Specification”), that allows for developing interactive services and
applications over interoperable radio modules and data communication
protocols. The objective of this paper is to provide an overview of the
protocols in the Specification, their capabilities and the relation to each other
(referred to as the “Bluetooth protocol architecture”). Moreover, a number of
usage models identified by the Bluetooth SIG will be presented and it will be
shown how (and which of) these protocols are stacked to support these usage
models.
1.1 Bluetooth Protocol Stack
The ultimate objective of the Specification is to allow applications written in a
manner that is conformant to the Specification to interoperate with each other.
To achieve this interoperability, matching applications (e.g., corresponding
client and server application) in remote devices must run over identical
protocol stacks. The following protocol list is an example of a (top-to-bottom)
protocol stack supporting a business card exchange application: vCard →
OBEX → RFCOMM → L2CAP → Baseband. This protocol stack contains both
an internal object representation convention, vCard, and “over-the-air”
transport protocols, the rest of the stack.
Different applications may run over different protocol stacks. Nevertheless,
each one of these different protocol stacks use a common Bluetooth data link
and physical layer, see more details on the protocol layers in the next section.
Figure 1 shows the complete Bluetooth protocol stack as identified in the
Specification on top of which interoperable applications supporting the
Bluetooth usage models are built. Not all applications make use of all the
protocols shown in Figure 1. Instead, applications run over one or more
vertical slices from this protocol stack. Typically, additional vertical slices are
for services supportive of the main application, like TCS Binary (Telephony
Control Specification), or SDP (Service Discovery Protocol). It is worth of
mentioning that Figure 1 shows the relations how the protocols are using the
services of other protocols when payload data needs to be transferred over
air. However, the protocols may also have some other relations between the
other protocols. E.g., some protocols (L2CAP, TCS Binary) may use LMP
(Link Manager Protocol) when there is need to control the link manager.
Bluetooth Protocol Architecture Page 5 of 20
Introduction 29 September 1999 5
Host Controller Interface
IP
RFCOMM
WAPOBEX
A
udio
T
CPUDP
TCS BIN
vCard/vCal
WAE
L2CAP
SDP
PPP
AT-
Commands
Baseband
LMP
Bluetooth Radio
Figure 1 Bluetooth Protocol Stack
As seen in Figure 1, the complete protocol stack comprises of both Bluetooth-
specific protocols like LMP and L2CAP, and non-Bluetooth-specific protocols
like OBEX (Object Exchange Protocol) and UDP (User Datagram Protocol). In
designing the protocols and the whole protocol stack, the main principle has
been to maximize the re-use of existing protocols for different purposes at the
higher layers, instead of re-inventing the wheel once again. The protocol re-
use also helps to adapt existing (legacy) applications to work with the
Bluetooth technology and to ensure the smooth operation and interoperability
of these applications. Thus, many applications already developed by vendors
can take immediate advantage of hardware and software systems, which are
compliant to the Specification. The Specification is also open, which makes it
possible for vendors to freely implement their own (proprietary) or commonly
used application protocols on the top of the Bluetooth-specific protocols. Thus,
the open Specification permits the development of a large number of new
applications that take full advantage of the capabilities of the Bluetooth
technology.
