Acacia Research subsidiary, Cell and Network Selection (CNS) filed a single suit against Huawei, MetroPCS, Yulong Computer, and ZTE, alleging that 4G LTE mobile devices supplied by Huawei, Yulong and ZTE and sold by MetroPCS infringe a patent related to cellular signal optimization. Plaintiff CNS has filed one prior suit in December 2011 against AT&T, HTC, and Sierra Wireless.  The patent-in-suit was assigned to SK Telecom in January 2003. According to the complaint, CNS holds all substantial rights and interest in and to the patent-in-suit, but no assignment to CNS has been recorded with the USPTO to date.  10/23, Eastern District of Texas, no judge yet assigned, 6:2012cv00802.