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DirecTV's 1st MPEG4 Satellite Launch Successful

Posted by CmdrTaco on from the final-frontier-seems-a-little-boring-lately dept.

tivoKlr writes "Looks like the 1st Spaceway satellite to provide "1500 channels of HD" has made it successfully into space. MPEG4 compression and local HD channels, something that the cable company can't offer in my area." Unfortunately the new satellite obsoletes the HD Tivo, and there's no word on when there will be a new one.

6 of 291 comments (clear)

  1. Re:For someone not hip on the lingo by Dios · · Score: 4, Informative


    I believe the High Def Tivo uses MPEG2 for its data streams, won't be capable of decoding the MPEG4 streams.

  2. Re:In this kind of setup... by gevmage · · Score: 4, Informative

    Digital TV has 18 different formats (resolutions), 6 of which are considered "HD". A couple of them are equivalent to NTSC resolution; 640x480 pixels. So NTSC stuff would presumably be broadcast in the standard appropriate digital format, taking up less bandwidth than one of the HD formats.

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  3. Re:Satellites are linear not digital by skaeight · · Score: 5, Informative

    Actually, no they couldn't have. For one reason. Bandwidth. They are completely maxed out right now. They couldn't have added 1 more HD channel, let alone 1500 additional HD channels. Each HD channel is something like 15 SD channel.

    The only reason they are able to do this is because they are going to be transmitting using a different band - KA. The current DirecTV sattelites transmit in the KU band. So they'll be using their existing orbital slots 101, 110, & 119 to broadcast on a different wavelenght.

    Unfortunately this is going to be mean a larger dish will be required. Google dish network superdish for an idea of how big it is. Dish Network already does broadcast some local channels in KA band.

  4. Re:Quality of MPEG4 signals? by flimflam · · Score: 4, Informative

    Yes, though not at the specific data rates used for broadcast. In general MPEG4 is vastly superior to MPEG2, however. Also, an MPEG2 stream would never be recompressed as MPEG4, the broadcaster would feed the uncompressed signal into the MPEG4 compressor. All in all this is a move to increase quality at the same bandwidth.

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  5. Ka spot beams by TheSync · · Score: 5, Informative

    The "killer technology" on the Spaceway birds are their ability to form tight "spot beams" using Ka band (~20 Ghz) downlink signals.

    The spot beams are formed using a 1500 element phased array. The array can form as many as 780 downlink spot beams and 112 uplink spot beams across the US. Compare this with a typical Ku-band (~12 GHz) satellite which has a single beam over the entire US.

    Spaceway uses digital regenerative switching of up to 10 Gbps, as opposed to the analog transponders of most geosynchronous communications satellites (despite the fact that most of those transponders are used with digital services these days).

    Spaceway was originally supposed to provide satellite point-to-point and point-to-multipoint IP connectivity, but that was dropped in favor of providing massive localized HDTV capacity using spot beams.

    Unfortunately, Ka band is more sensitive to rain fade outages than Ku band.

    1. Re:Ka spot beams by Anonymous Coward · · Score: 5, Informative

      Disclaimer, I work on the SPACEWAY project. The rain fade is mitigated by constant updates of weather data (we're talking Gigs per day of data transfer). This data is used to tell the satellite where to pump up the signal to get through the clouds. Areas of clear sky get the signal reduced. This helps deal with rain fade and also prolongs the life of the satellite since it keeps power consumtion low.