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Sky Digital BSkyB, Freesat & Saorsat support forum
Sky+ HD
sky+/HDTV confused?
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<blockquote data-quote="waydownsouth" data-source="post: 153195" data-attributes="member: 199167"><p>Well not quite correct, Sky's transmission on TP33 on Astra 2B is infact in 8PSK as per the DVB-S2 spec, not QPSK as used by DVB-S, that said your current dish/lnb is fine, just the STB needs replacing for one that supports DVB-S2, MPEG4 and HD frame formats.</p><p></p><p>DVB-S2 using 8psk gives roughly a 30% increase in throughput for the same transponder bandwidth, and MPEG4 allows acceptable 1080i pictures at 13Mb/s as opposed to 19Mb/s using MPEG2.</p><p></p><p>DVB-S2 has the added feature that it can be operated in a hieracical mode, that allows both QPSK and 8PSK transmissions simultaneously, thus older DVB-S stbs can see the qpsk traffic, but newer DVB-S2 stbs can see both transmissions, therefore it is possible for a transponder to carry all or near all of its old previously allocated SD payload for existing STBs and in addition carry a single HD channels payload for 8psk stbs. DVB-S2 allows for operation in either this hybrid method or for an even greater throughput in a 8psk only mode.</p><p></p><p>Cyril</p></blockquote><p></p>
[QUOTE="waydownsouth, post: 153195, member: 199167"] Well not quite correct, Sky's transmission on TP33 on Astra 2B is infact in 8PSK as per the DVB-S2 spec, not QPSK as used by DVB-S, that said your current dish/lnb is fine, just the STB needs replacing for one that supports DVB-S2, MPEG4 and HD frame formats. DVB-S2 using 8psk gives roughly a 30% increase in throughput for the same transponder bandwidth, and MPEG4 allows acceptable 1080i pictures at 13Mb/s as opposed to 19Mb/s using MPEG2. DVB-S2 has the added feature that it can be operated in a hieracical mode, that allows both QPSK and 8PSK transmissions simultaneously, thus older DVB-S stbs can see the qpsk traffic, but newer DVB-S2 stbs can see both transmissions, therefore it is possible for a transponder to carry all or near all of its old previously allocated SD payload for existing STBs and in addition carry a single HD channels payload for 8psk stbs. DVB-S2 allows for operation in either this hybrid method or for an even greater throughput in a 8psk only mode. Cyril [/QUOTE]
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Sky Digital BSkyB, Freesat & Saorsat support forum
Sky+ HD
sky+/HDTV confused?
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