RCA, along with its "radio group" allies of Westinghouse and General Electric, responded by creating a small network of its own, centered on WJZ. Due to AT&T's interpretation of a patent-rights cross-licensing agreement, the telephone company claimed the sole right to sell airtime, so WJZ was not able to charge for advertising, and again there were technical limitations, since the network had to use inferior telegraph lines to interconnect its stations.
