Jignesh, Discovery HD in 5.1 may come in TS HD. I can not comment on that as I don't have that. BTW how is your setup/connection?And one more thing, AFAIK, mono can not be made into surround sound. A stereo can be. But still it should be good enough. I have experimented this by encoding a 44.1 KHz song from audio CD into mp3 and feeding that stereo into Dolby PL II. Its not able to make it into surround sound below certain bit rates.To all, I have seen ads for Discovery HD saying that the audio is in 5.1. But I have never seen an ad for NatGeo HD. But every DTH operators ad says that the audio is in 5.1.