Paper 1

WIRELESS COMMUNICATION

BY, R.RAMAGURU, G.ATHIPATHY, B.DEEPAK KUMAR. KUMARAGURU COLLEGE OF TECHNOLOGY.

WIRELESS COMMUNICATION „ „ „

Beginning Definition Categories ) Bluetooth ) Infra ) WiFi

Red

Bluetooth „ „ „ „ „

History Definition Early Days Versions Goals & Vision

Technical Features Connection Type

Spread Spectrum (Frequency Hopping) & Time Division Duplex (1600 hops/sec)

Spectrum

2.4 GHz ISM Open Band (79 MHz of spectrum = 79 channels)

Modulation

Gaussian Frequency Shift Keying

Transmission Power

1 mw – 100 mw

Data Rate

1 Mbps

Range

30 ft

Supported Stations

8 devices

Bluetooth FHSS „ „ „

„

Reduce interference with other devices Pseudorandom hopping 1600 hops/sec- time slot is defined as 625 microseconds Packet 1-5 time slots long

Time-Division Duplex Scheme „

„

„

Channel is divided into consecutive slots One packet can be transmitted per slot Strict alternation of slots between the master and the slaves „ „

Master - EVEN slot Slave - ODD slot

Bluetooth Devices

Piconet - Structure Master Active Slave Parked Slave Standby

All devices in piconet hop together.

Protocol Stack ƒ Composed of protocols ƒ Create, configure and manage ƒ Both physical and logical links ƒ Allow higher layer protocols and applications to pass data

Packet Structure 54 bits

72 bits

Access Code

Header

Voice No CRC No retries FEC (optional)

0 - 2744 bits

Payload

header

Data

CRC

ARQ FEC (optional)

Connection State Machine Inquiry

Page

Standby

Connected Transmit data

Park

Hold

Sniff

Security „ „

„ „

Link Level Encryption & Authentication Personal Identification Numbers (PIN) for device access Long encryption keys are used Further encryption can be done

Comparison Bluetooth

IrD

Wi Fi

Point to Multipoint

Point to point

Point to Multipoint

Range 10 m

Range 1 m

Upto 100s of Meters

Low Power

Low Power

High Power

Minimal Hardware

Minimal Hardware

Large no of Hardwares

Advantages „ „ „ „ „ „ „ „

An economic wireless solution Multiple levels of security Multiple devices No network problem No manual configuration Low Latency Low power consumption Faster acknowledgement

Application „

Mobile commerce

„Automotive

„Portable

industry

power transfer

„Bluetooth

Messaging

Future ƒBluetooth 3.0 (TDP) ƒ Bluetooth low energy (Wibree) ƒBluetooth High Speed

References „ http://www.bluetooth.com „ http://www.google.com „ http://www.brainboxes.com „ http://www.palowireless.com

Thank You