BlueTooth Basics

What is Bluetooth?

is a universal radio interface in the 2.4 GHz frequency band that enables electronic devices to connect and communicate wirelessly via short-range (10-100 m), ad-hoc networks.
Peak data rate : 1 Mbps
Low power : peak tx power <= 20 dBm Low cost : target is $5-10 per piece Ability to simultaneously handle both voice and dataLine of sight not required



Bluetooth History:

Invented in 1994 by L. M. Ericsson, Sweden
Named after Harald Blaatand “Bluetooth”, king of Denmark 940-981 A.D.
Bluetooth SIG founded by Ericsson, IBM, Intel, Nokia and Toshiba in Feb 1998
More than 1900 members today
Bluetooth version 1.0 and 1.1 have been released



Bluetooth Air Interface:

Piconet channel definition
Physical link definition
Packet definition



Piconets, Masters and Slaves:


In principle each unit is a peer with the same hardware capabilities
Two or more Bluetooth units that share a channel form a piconet
One of the participating units is becomes the master (by defn the unit that establishes the piconet).
Participants may change roles if a slave unit wants to take over as master
Only one master in a piconet.
Upto 7 slaves



Inter-piconet communication:

A unit may particpate in more than one piconet on a TDM basis.
To participate on a piconet it needs the master’s identity and the clock offset.
While leaving the piconet it informs the master
The master can also multiplex as slave on another piconet. But all traffic in its piconet will spended in its absence.
for more deatils read it:
www.it.iitb.ac.in/~it644/lectures/bluetooth.ppt