Transponders correspond to the amount of bandwidth an operator has, unfortunately it seems SatCodx (now SatBeams) is not displaying channel bandwidth otherwise we could have compared the amount of bandwidth taken up by a (MPEG2) SD channel (IIRC 1 - 4 Mbps) compared to a (MPEG4) HD channel.
Tata Sky will almost certainly start with a handful of HD channels in a premium package and of course a new MPEG4 complaint STB will be required.
Current customers ( those who do not have Tata Sky Black box MPEG4 enabled) who have MPEG2 boxes will they not be able to enjoy HD channel viewing. Old customer's too should derive benefits of new offerings.
Tata Sky will almost certainly start with a handful of HD channels in a premium package and of course a new MPEG4 complaint STB will be required.
Current customers ( those who do not have Tata Sky Black box MPEG4 enabled) who have MPEG2 boxes will they not be able to enjoy HD channel viewing. Old customer's too should derive benefits of new offerings.