Bluetooth Technology

[Kalyan]

Bluetooth Technology

* A new global standard for data and voice

* Goodbye Cables ! Bluetooth Specifications:- Connection Type Spread Spectrum (Frequency Hopping) MAC Scheme FH-CDMA Spectrum 2.4 GHz ISM Modulation Gaussian Frequency Shift Keying Transmission Power 1 mw 100 mw Aggregate Data Rate 1 Mbps Range 30 ft Supported Stations 8 devices Voice Channels 3 Data Security- Authentication Key 128 bit key.

Data Security-Encryption Key 8-128 bits (configurable) Bluetooth Protocol Stack Composed of protocols to allow Bluetooth devices to locate each other and to create, configure and manage both physical and logical links that allow higher layer protocols and applications to pass data through these transport protocols Transport Protocol Group *Radio Frequency (RF) -Sending and receiving modulated bit streams -Baseband -Defines the timing, framing -Flow control on the link.

*Link Manager -Managing the connection states. -Enforcing Fairness among slaves.

Power Management

*Logical Link Control &Adaptation Protocol -Handles multiplexing of higher level protocols

Segmentation & reassembly of large packets -Device discovery & QoS Master Slave

Master --Device in Piconet whose clock and hopping sequence are used to synchronize all other devices (slaves) in the Piconet.

It also carries out Paging procedure and also Connection Establishment.

Slaves **Units within the piconet that are syncronized to the master via its clock and hopping sequence. --After connetion establishment, Slaves are assigned a temporary 3 bit member address to reduce the no. of addresing bits required Physical Link Types

**Synchronous Connection Oriented (SCO) -Point to Point Full Duplex between Master & Slave -Established once by master & kept alive till released by Master -Typically used for Voice connection ( to guarantee continuity ) -Master reserves slots used for SCO link on the channel to preserve time sensitive information **Asynchronous Connection Link (ACL) -It is a momentary link between master and slave. -No slots are reserved. -It is a Point to Multipoint connection.

-Symmetric & Asymmetric links possible Access Code Purpose Synchronization DC offset compensation Identification Signaling Types Channel Access Code (CAC) Identifies a piconet.

Device Access Code (DAC) Used for signalling procedures like paging and response paging. Inquiry Access Code (IAC) General IAC is common to all devices, Dedicated IAC is for a dedicated group of Bluetooth devices that share a common characteristic. Packet Header Addressing ( 3 bits ) Packet type (4 bits ) Flow Control ( 1 bit ) 1-bit ARQ Sequencing ( 1 bit ) HEC ( 8 bit ).