Here is the bluetooth patents family that assertedly include claims directed to various cellphone manufacturer’s implementation of bluetooth.

From what I can tell, the argument is that the bluetooth standard, as a standard, does not assertedly infringe. The chips used by some bluetooth cellphone manufacturers (those made by Cambridge Silicon Radio) are not licensed and assertedly infringe. Washington Research Foundation did not sue CSR, asserting the patents against CSR’s customers (a famous tactic for gaining the attention of your real target).

While we can review the claims of the patents in the patent family, it is harder to gain access to some of the necessary details of the CSR chips so evaluation of the merits of these infringement claims is more difficult.