BROADCAST SYSTEMS •Symmetrical Communication System –same trasmission capabilities in both communication directions a-b,b-a. Eg.Telephones, GSM

•Asymmetrical Communication System -Client /Server Environments (Client need more data than server) www-Television Setup Box –Movies & Shopping Information (Between Channels)

•UNIDIRECTIONAL BROADCAST SYSTEMS

-High Bandwidth data stream exists from one sender to many receivers -Sender Optimizes the transmitted data for the whole group of user

BROADCAST TRANSMISSION

Cyclical Repetition of Data

• Broadcast sender doesn't know when a receiver starts listen to transmission

• Cyclical representation of data blocks send via broadcast is BROADCAST DISK

Digital Audio Broadcasting• Single Frequency Network

• VHF /UHF

• DQPSK –Modulation

• FEC & Uses Guard Spaces

• Two Mechanisms

(i) Main Service Channel (Msc) (ii) Fast Information Channel (FIC)

DAB Mechanisms

DAB SENDER

DAB RECEIVER

Multimedia Object Transfer Protocol

• Broad Range of Different Receiver Capabilities

• Atleast able to recognize all program associated data

• DAB defines a standard for Data Transmission MOT (to support all data

formats)

Formats • MHEG -> Multimedia&HyperMediaInformation Coding

Experts Group

• JAVA

• JPEG –> Joint Photographic Experts Group

• ASCII

• MPEG -> Moving Pictures Experts Group

• HTML,HTTP,BMP

• GIF-> Graphics Interchange Format

MOT Structure

Digital Video Broadcasting

DVB

Convergence of Broadcasting and Mobile Communication