Originally Posted by MDBones
I think what really happened is that I was moved from the better Sirius satellite system to the inferior XM satellite system. I've read somewhere that Sirius is doing that after free trials expire so as to not "overload" the Sirius satellites. I've confronted Sirius about this satellite switching... they neither admit or deny doing this.
My other vehicle is an 08 Honda Accord with the original XM radio. It gets driven the same routes as my GC. Never once had an issue with the service "reloading" in the 7 years I've owned the car.
short answer is they probably just need to send the signal.
Long answer (and if I'm understanding correctly)=
there's no switching satellites possible. The radios can pick up XM or sirius sat signals but not both. The sats were two different incompatible systems. (think of it like trying to use an old ATT phone on Verizon- can't work). Different frequencies. Different compression systems. Different access control.
Our radios, uconnect 8.4, actually have neither "sirius" not "XM" service. It's a NEW service called "siriusXM" which is the combined company's move towards combining the 2 different services to create one system in the future. Basically it's a superset of XM. They use XM satellites and then there's extra channels provided which are only decipherable by "siriusxm" chipsets. In the end at some future date XM is the satellite system that will survive and they will kill off the sirius satellites (probably when they run out of fuel they wont be replaced)
The new "siriusxm" radios can receive the hierarchical modulation of the new system.
SIRIUS to Increase Programming Capacity Over Its Existing Satellite Radio System - SiriusXM Radio
In simple terms the way it was described to me is that original XM (or sirius for that matter) radios can see zero's or 1's. But pretend siriusxm started transmitting in decimals (on the XM sats). So they can send a 0.8 or a 0.9 now- the old radio will 'round' them to a 1 but a new radio knows that there is a difference between a 0.8, a 0.9, or a 1.0. They don't get 10 times as much data becasue now that the signal is so much more granular they have to add a lot more error correction. So in the end they can add maybe 25% more channels and so that's why we get more channels that neither "sirius" nor "XM" radios can get. (i think the description is an analogy and the reality is more complex)
(there's alternate theories in the 'net that it's not necessarily the new modulation that carries the new channels but perhaps xm juggled their limited bandwidth and reassigned some of the frequencies they used for ground networks. From what i understand of those theories the old "XM" radios would actually lose out on the repeater networks in cities so anyone with an "XM" radio who went under a bridge or next to a tall building on the south would lose signal. Since there's no giant outcry of people complaining about this on XM only and not sirius i am not sure that's possible"
you can compare the lineups on the 3 different types of radios here:
Channel Lineup - SiriusXM Radio
use the dropdown by 'what type of radio do you have to see what's specific to each type of hardware'
you can look up nba radio as example.
on an "xm" radio it's channel 86
on a "sirius" radio its channel 207
Since our "siriusxm" radios "see" "XM" we also get it on channel 86
next- channel 403- "just for laughs"
xm - online only- invisible to these radios
sirus - online only- invisible to these radios
sirius xm - on the radio AND online- the hierarchical modulation at work.