Television broadcasting in the United States was heavily influenced by radio. Early individual experimental radio stations in the United States began limited operations in the 1910s. In November 1920, Westinghouse signed on "the world's first commercially licensed radio station", KDKA in Pittsburgh, Pennsylvania. Other companies built early radio stations in Detroit, Boston, New York City and other areas. Radio stations received permission to transmit through broadcast licenses obtained through the Federal Radio Commission (FRC), a government entity that was created in 1926 to regulate the radio industry. With few exceptions, radio stations east of the Mississippi River received official call signs beginning with the letter "W"; those west of the Mississippi were assigned calls beginning with a "K". The number of programs that these early stations aired was often limited, in part due to the expense of program creation. The idea of a network system which would distribute programming to many stations simultaneously, saving each station the expense of creating all of their own programs and expanding the total coverage beyond the limits of a single broadcast signal, was devised.