MUMBAI, FEBRUARY 21: All India Radio (AIR) is planning to introduce terrestrial digital audio broadcasting service in the VHF band.A pilot DAB transmission will be carried out from four metro cities including Delhi and Mumbai in 2001. For terrestrial DAB, the Eureka-147 system has been adopted. "It is a versatile technology free from aberrations. Transmission can be received in mobile and stationary conditions," said K M Paul, chief engineer (development), All India Radio. Incidentally, DAB receivers are being manufactured by 18 companies internationally.AIR is also preparing to introduce digital broadcasting in AM band (below 30 MzH). A pilot transmission will start by 2001 following the emergence of single world wide standard. "The standard should be ready by October," said Paul. AIR will modify the existing high power SW transmitters for DAB transmission. There will be a simulcast during the transition period.
AIR recently obtained the VHF band-III clearance from the ministry. It plans to run the pilot project to make the engineers acquainted with the technology. Digital radio programme production will also require a different style, Paul said.
With DAB service, AIR will be capable of transmitting multiple audio channels. It will deliver near CD quality audio and be capable of transmitting multi media programming. There will be quality enhancement and interference free reception. "We can have portable and mobile receptions. The broadcast will be free from multi-path interference. Besides, DAB service is highly power and spectrum efficient," said Paul.
AIR plans to pack up six numbers of CD quality stereo music or 12 numbers of CD quality mono music as multiple channels will be possible from the same transmitter. AIR also has the option of launching a number of news channels by making a hybrid of news and music. "We can have several news channels as they require less bandwidth," said Paul.
Digital broadcast will enable AIR to provide additional services like providing still picture of the musicians and programme associated data. Besides, it can run an information channel, provide stock market scrolls, tourism, economics, transport, weather and public utility information in a text form. "We can broadcast TV picture through radio transmitters. But there is still a long way to go for charging money from digital broadcast," said Paul.
The commercial service of digital audio broadcast has not taken off because of the high cost of receivers. But to radio stations, it can provide new streams of revenue. "We can encrypt service to specific audiences. Radio paging is also possible," said Paul.
Copyright © 2000 Indian Express Newspapers (Bombay) Ltd.