U.S. Cellular is one of the largest full-service wireless carriers in the United States. The company provides a range of wireless products and services and a high-quality network to increase the competitiveness of local businesses and improve efficiency of government operations. It is a subsidiary of Telephone and Data Systems, Inc. U.S. Cellular provides wireless service coverage for Telephone and Data Systems in midwest markets. The company caters to retail and business customers, offering a wide range of products and services and local, regional and national calling plans, enhanced wireless services, mobile messaging, prepaid services, office products, data services and roadside assistance. The company generates revenues from 2 sources: Service and Equipment Sales. Service Consists of charges for access, roaming, airtime and value-added services, charges to other wireless carriers for roaming services. Equipment Sales involve into Selling of handsets and accessories to customers and agents.