United States Cellular Corporation (U.S. Cellular) is a wireless telecommunications service provider. The Company operates in one segment, wireless operations, and all of its wireless operating markets are in the United States. At December 31, 2013, U.S. Cellular's provided wireless voice and data services to approximately 4.8 million customers in 23 states. U.S. Cellular is a majority-owned subsidiary of Telephone and Data Systems, Inc. U.S. Cellular uses roaming agreements with other wireless carriers to provide service to its customers in areas not covered by U.S. Cellular's network. U.S. Cellular's ownership interests in wireless licenses include both consolidated and investment interests in licenses covering portions of 30 states and a total population of 58.0 million as of December 31, 2013.