They are fundamental to the operation of GSM / CDMA networks. Patent portfolio's like these in the mobile arena are pretty well only trumped by Qualcomm's, TI's, and probably Motorola's.

My opinion though is that the actual interaction to the cell network is not solely done by android, but by the chipset on the phone mostly. They could sue Google I'm sure, but I bet people like Motorola and Qualcomm would have something to say about that to protect Google and Androids chip purchasing wallet.