We in India are familiar and watched DD’s analogue terrestrial channels (mostly DD1, DD News and regional channel time shared with DD1). But in 4-5 years we could enjoy more DD channels in Digital mode, and if permitted some private channels could also be seen on terrestrial transmitted as ‘Digital Terrestrial Transmission’ (DTT).
In India we are so far aware of Digital TV through satellite (DTH), where digital channels are carried over satellite signals and sent to customer’s home. In DTT similarly digital TV signals are carried over RF signals, but broadcasted from terrestrial transmitters over VHF/UHF frequencies. The standard commonly used for DTT is DVB-T which is widely adopted. Besides 8VSB for ATSC (used in North America) and ISDB-T (used in Japan & Brazil) are the standards used for DTT.
DTT would have advantage over analogue transmission. On the single frequency more digital channels can be transmitted. Audio/Video quality is better compared to analogue channels. DTT also has benefit of transmitting EPG and other active services.
But DTT channels cannot be received through conventional TV. We would need Set Top Box or TVs with built in digital tuner for DTT reception.
India has adopted DVB-T standard. Turning digital, will improve DD’s transmission strength to accommodate about 6-8 channels/transmitter. Interested private broadcaster could use the additional channels to offer paid TV services to nearly 120 million homes. They could also put up digital transmitters at their own cost on DD’s towers and add more channels to the bouquet
Doordarshan has already conducted trials of its digital terrestrial transmission services in Delhi. In 2006, the projected cost of migrating to digital had been estimated at Rs 3,531 crore by a Committee of Financial Restructuring of Prasar Bharati. Earlier, an expert group set up by the Prime Minister’s Office had set 2015 as the deadline to phase out analogue TV transmission completely. Prasar Bharti was to start DTT in 2010; the report of this group had, keeping the Commonwealth Games in mind, even coined a slogan ‘Digital Delhi by 2010’ for the Capital.