The DVB (Digital Video Broadcast) project group has developed a family of interrelated internatonal standards for digital television broadcastingbvia different transmission media.These are DVB-T for digital terrestrial transmission, DVB-S for digital satellite trasmission and DVB-C for digital cable transmission.

A very significant feature of these standards is that all three of them have identical source coding/compression and service multiplexing/transport sections. These two sectionssare based on the internationally acclaimed MPEG-2 standard. However channel coding/modulation part of each of the three is optimized for the respective transmission media. Thus whereas satellite and cable transmission are based on single carrier modulation schemes of QPSK and QAM, Terrestrial transmission uses a multicarrier modulation scheme called OFDM (Orthogonal Frequency Division Multiplexing).

The such time integrated digital TV (IDTV) sets become cheaper, digital set top boxes will be utilized in the home for the reception of all three signals. It is thus apparent that, the availablity of set top boxes at affordable prices is going to be the major factor which will ensure a fast take up of these services in the country. By adopting the three above mentioned interrelated international standard for digital transmission in India an important goal has been realized, that of ensuring maximum commonality in the components used in the STBs for the three media, leading to an overall decrease in the price of STBs arising from economics of scale.

Yet another important feature which will lead to a cost reduction of STBs is to make the STB, to the extent possible to be based on an "Open Architecture" and also make it 'Interoperable' across different networks.

To read the FULL PAPER in PDF format please click here - Digital Set-Top Box - Open Architecture/Interoperability Issues