XM and Sirius have already agreed to share technology toward the end
of total interoperability and are in fact required to do so by the
FCC. That's why.

On 4 Feb 2005 11:24:06 -0800, "Invader3K"
wrote:

It's called a licensing agreement. XM would never allow a manufacturer
to make a radio that would support both XM and Sirius. I don't
understand why people can't figure that out.