BLUETOOTH AND ITS APPLICATION IN MOBILE PHONES                                                                                                                                                  BLUETOOTH AND ITS APPLICATION IN MOBILE PHONES

Started by Ericsson Mobile Communication in 1994 Short range wireless technology Operates in ISM band at 2.4 to 2.485 GHz using spread spectrum,frequency hopping full duplex signal at a nominal rate of 1600 hops/sec.

ADVANTAGE: Low cost Low power Robustness The ability to simultaneously handle both data and voice transmissions

COMMUNICATION Short-range adhoc networks known as piconets Communication is done through Master units

Establishing network connections

PROCEDURES Inquiry – This enables a unit to discover which units are in range and what their device addresses and clocks are. Paging- An actual connection can be established.

The master must poll the slave by sending POLL or NULL packets to which the slaves will respond. Link Manager Protocol procedure is carried out. LMP_host_ connection_req LMP_accepted or LMP_not_accepted

VARIOUS STATES OF BLUETOOTH                                                                                                                

BLUETOOTH OPERATIONAL STATUS                                                                                                         

BLUETOOTH’S SECURITY & ERROR CORRECTION SCHEMES Encryption and authentication Frequency-hopping scheme in 1600 hops/sec Automatic output power adaption Forward Error correction Automatic Repeat Request

ARQ_Automatic Repeat Request                                                                                                                                        On 2 occasions, the transmitted data blocks get corrupted, which is detected by the recipient. So the next time that recipient get a chance to communicate with that sender (i.e. at the next appropriate timeslot), the recipient sends a Negative Acknowledgement (a NAK, depicted in red), which prompts the other party to re-transmit that data block.

APPLICATION IN MOBILE PHONES                   

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