Fighting to maintain its access to major markets for next-generation communications, Chinese tech giant Huawei is challenging the constitutionality of a U.S. law that limits its sales of telecom equipment. Huawei's chief legal officer, Song Liuping, said Wednesday that Huawei filed a motion asking a court in Plano, Texas, for a summary judgment on whether a U.S. military spending provision that bars the government and its contractors from using Huawei equipment is constitutional.