ok, based on JBHorner's logical comments... i called the 800 number of BMW Assist and spoke with someone. He told me it IS cellular based, not satellite for the communication part. he said it uses Verizon Wireless.

HOWEVER, he did say that the BMW Diagnostics send information to service centers directly through a satellite system and do not use cellular. so... seems i was mistaken in my original post.

darn.... and i thought we actually had something cool here.