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Sirius moving to XM Technology

J

jasper933

I have been reading some articles and curious why Sirius is moving to the XM technology platform. When Sirius was designed, it was done to limit the need for a large amount to terrestrial repeaters. This is why Sirius has few repeaters than XM.

Quote from Wikepedia.
"Satellites Radiosat 1 through Radiosat 3 fly in geosynchronous highly elliptical orbit (Tundra orbit) in a 24-hour orbital period. The elliptical path of its satellite constellation ensures that each satellite spends about 16 hours a day over the continental United States, with at least one satellite over the country at all times. The orbit allows the satellites to broadcast from directly overhead the continental United States, avoiding the problem of large buildings or objects blocking the signal and requiring a much smaller terrestrial repeater network than does sister network XM."


Is the XM technology better or more efficient than Sirius? Can someone educate me more? Thanks.
 
A few reasons:

1.) Sirius uses an ancient codec called ePac to broadcast its audio. XM uses the more efficient aacPlus to broadcast, and uses AMBE for Traffic and Weather channels. Their new Sirius XM units use an even more efficient version of aacPlus. This allows XM to cram more channels into the same space with the same audio quality.
2.) While XM is able to add, delete, and update channels on the fly, Sirius has to shut off and reboot its entire system. This is the frequent complaint from Sirius subscribers regarding "channel updates" and why new channels may still sport names of old channels that haven't been on the system in a long time.
3.) The XM infrastructure allows engineers to shuffle bandwidth wherever it is necessary, turning channels on and off and redirecting channels. This is how XM is able to have part time sports play-by-play channels. Sirius cannot support "part time channels." They need to be on or off at all times. This is also why Sirius may preempt more than 25 channels at once for sports.
4.) Due to a hardware limitation, there are still a significant number of Sirius units in circulation that won't allow customers to access more than 135 channels, thus shutting them out of the Sirius Premier package completely. Newer units have overcome this hurdle, but there are still too many of these older units in circulation.
5.) And while this is more of a minor annoyance than anything, the XM Premier package needs to be grouped separately from the rest of the channels, with no non-Premier channels sitting inbetween, in order for Sirius to offer it on a separate tier. They cannot share the same channel numbers on both without XM having to mirror Sirius' channel mapping.

You have already explained how the satellites work. I'm not educated on how these companies get permission to operate their satellites, but it's more practical that XM simply adds a geosynchronous highly elliptical orbiting satellite as opposed to Sirius ripping out their entire infrastructure and replacing everyone's units.
 
So couldn't this just mean they're swapping out the back-end technology, while continuing to use the Sirius satellites to broadcast the audio?
 
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