1. ® The Bluetooth Architecture APIs, L2CAP, Link Management, Baseband, and the Radio

2. ® www.xilinx.com/esp RF (radio and antenna) Audio Control L2CAP (data) Baseband Link Manager API 1 API 2API 3API... API n Application Program Interface libraries Logical Link Control & Data Adaptation Protocol Physical link control Data processing & transmission management Transmission/reception The Bluetooth Architecture Five Layers to Wireless Communications  Bluetooth is enabled through 5 layers of software and hardware  These layers distribute functional responsibility —The bottom layers handle the lowest level details —Progressively higher layers handle ever more general concerns

3. ® www.xilinx.com/esp Application Program Interface Libraries  APIs connect the host system’s application software to the Bluetooth communications sub- system  New capabilities that Bluetooth enables are supported through new APIs —Telephony Control protocol Specification (TCS) —Service Discovery Protocol (SDP) —Etc. Bluetooth sub-system Host Application(s) TCS SDPAPI... API s...

4. ® www.xilinx.com/esp API s... Application Program Interface Libraries  RFCOMM and other APIs on PCs provide support for legacy communications capabilities —PPP (TCP/IP) —OBEX (IrDA) —etc. Bluetooth sub-system Host Application(s) RFCOMM OBEX AT Commands UDPTCP IP Legacy APIs

5. ® www.xilinx.com/esp L2CAP Logical Link Control and Adaptation Protocol  The L2CAP performs four major functions —Managing the creation and termination of separate, independent, Logical Links for each desired connection –Including support for broadcast 1-to-many communications —Dictating and enforcing QoS requirements —Data adaptation between application native and Bluetooth baseband formats for each connection —Multiplexing to allow multiple concurrent connections over the single common radio interface

6. ® www.xilinx.com/esp Logical Link Control and Adaptation Protocol  The L2CAP creates and manages independent Logical Links through structures called “Channels”  Channels define the relationship between a specific host application and a specific remote device (or group of devices) and another specific application —Defines the source, destination(s), protocol, QoS, etc. API 1API 2API... Channel 1 Source Destination(s) Protocol QoS Channel 2 Source Destination(s) Protocol QoS Channel... Source Destination(s) Protocol QoS L2CAP

7. ® www.xilinx.com/esp L2 CAP Logical Link Control and Adaptation Protocol (2)  The L2CAP also adapts and multiplexes data to and from the APIs —Segmentation And Reassembly (SAR) adapts data streams to/from their native formats for Bluetooth’s baseband —Multiplexing enables simultaneous transmission of multiple channels over the radio interface API 1 API 2 L2CAP API... Channels SAR Multiplexing

8. ® www.xilinx.com/esp Link Manager  The Link Manager is responsible for the physical link resources in the system and performs all link creation, management, and termination operations —Establishes outbound links upon request from the L2CAP and confirms successful completion —Intercepts and processes inbound Link Control operations from other devices independently –Clock synchronization updates etc. —Monitors on-going link status and closes any link that fails with the L2CAP  QoS negotiation  Pairing and Authentication  Definition and maintenance of timing parameters  Link monitoring and fault handling  Etc.

9. ® www.xilinx.com/esp Baseband Baseband Bitstream Processing  The Baseband controller is responsible for all bitstream processing immediately before and after RF transmission  The typical processing dataflow is as follows:  Packet construction/deconstruction  Error correction encoding/decoding  Encryption/decryption  Data whitening/de-whitening  Sequence numbering and error handling Payload CRC Generation Payload Encryption Payload Whitening Packet Sequence Numbering Header Error Correction Header Whitening Header FEC Encoding Payload FEC Encoding MandatoryOptional Payload Error Checking Payload Decryption Payload De-whitening Packet ACK/NAK HEC Checking Header De-whitening Header FEC Decoding Payload FEC Decoding RF Interface

10. ® www.xilinx.com/esp Baseband  The Baseband controller is also responsible for a number of low level operational responsibilities —Inquire scanning and response —Page scanning and response —Hold, Sniff, Park, and Sandby state management —Frequency hopping calculation —Etc.

11. ® www.xilinx.com/esp Radio  The Bluetooth radio performs all D/A and A/D processing of the I/O data stream —Accepts and supplies digital data from/to the baseband —Provides and accepts an analog signal to/from the antenna

12. ® www.xilinx.com/esp RF (radio and antenna) Audio Control L2CAP (data) Baseband Link Manager Application Host application Application Program Interface libraries Logical Link Control & Data Adaptation Physical link control Data processing & transmission management Transmission/reception API 1 API 2API 3API... API n Integrated device Bluetooth System Architecture Fully Integrated Implementation  In highly integrated systems these layers can all be co-resident on the same device —Even as far as both the host application and Bluetooth protocol stack running on the same microcontroller

13. ® www.xilinx.com/esp HCI driver Bluetooth System Architecture Modular Implementation RF (radio and antenna) Audio Control L2CAP (data) Baseband Link Manager Application Host application Application Program Interface libraries Host HCI driver Host HCI hardware Bluetooth module HCI hardware HCI firmware Logical Link Control & Data Adaptation Physical link control Data processing & transmission management Transmission/reception Host Controller Interface Transport Bus HCI firmware API 1 API 2API 3API... API n Host system Bluetooth module