The other day I activated a satellite radio in my car. Prior to activation I could listen to a few free channels. Afterwards, most of the channels were available. I am curious to know how it knows that I am allowed to listen to XM and to what channels I can listen, as I know there are premium stations available I do not get.
Thanks.
For those answering, I am a former EE major and 14 year IT veteran so an answer with some depth would be appreciated.