Bluetooth RESPONSIBLE Riku Mettala N B DATE WHITE PAPER Aug 25th 99 E MAIL ADDRESS riku mettala nmp nokia com DOCUMENT NO 1 C 120 1 0 STATUS 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 Bluetooth Protocol Architecture Page 2 of 20 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 Mett l 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 29 September 1999 2 Bluetooth Protocol Architecture Page 3 of 20 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 29 September 1999 3 Bluetooth Protocol Architecture 1 Page 4 of 20 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 Introduction 29 September 1999 4 Bluetooth Protocol Architecture vCard vCal WAE OBEX WAP UDP TCP Page 5 of 20 ATCommands TCS BIN SDP IP PPP RFCOMM Audio L2CAP Host Controller Interface LMP Baseband Bluetooth Radio Figure 1 Bluetooth Protocol Stack As seen in Figure 1 the complete protocol stack comprises of both Bluetoothspecific 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 reuse 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 Introduction 29 September 1999 5 Bluetooth Protocol Architecture 2 Page 6 of 20 Protocols in Bluetooth Architecture The Bluetooth protocol stack can be divided