DuMont struggled to get its programs aired in many parts of the country, in part due to technical limitations of network lines maintained by telephone company AT&T Corporation. During the 1940s and 1950s, television signals were sent between stations via coaxial cable and microwave links that were owned by AT&T. The service provider did not have enough circuits to provide signal relay service from the four networks to all of their affiliates at the same time, so AT&T allocated times when each network could offer live programs to its affiliates. In 1950, AT&T allotted NBC and CBS each over 100 hours of live prime time network service, but gave ABC 53 hours, and DuMont 37. AT&T also required each television network to lease both radio and television lines. DuMont was the only television network without a radio network, so it was the only network forced to pay for a service it did not use. DuMont protested AT&T's actions with the Federal Communications Commission, and eventually reached a compromise.