Originally Posted by robpp
each device has an ID. if i give them that ID they can send me a signal.
Do you mean they send dedicated stream to each radio unit? I find it difficult to believe. From reading on the subj my understanding that "radio stations" portion is one-directional and works like this: everybody receives all the channels. In addition special service signal is broadcast that includes unique information for all devices (subscription active/inactive; if active - what package is authorized). Each device receives complete service signal but only applies settings for it's own ID. This is why (I think) even after you subscription expires your radio still works for some time - because they don't push subscriber info out every day for every device.
The above is my understanding on how it works. I never really had Sirius radio before.