Although NBC in New York was known to have station-to-station television links as early as 1940 with WPTZ (now KYW) in Philadelphia and WRGB Schenectady, New York, DuMont received its station licenses before NBC resumed its previously sporadic network broadcasts after the war. ABC had just come into existence as a radio network in 1943 and did not enter network television until 1948 when its flagship station in New York City, WJZ-TV (now WABC-TV), began broadcasting. CBS also waited until 1948 to begin network operations, because it was waiting for the Federal Communications Commission to approve its color television system (which it eventually did not). Other companies, including Mutual, the Yankee Network, and Paramount, were interested in starting television networks, but were prevented from successfully doing so by restrictive FCC regulations, although the Paramount Television Network did have some limited success in network operations in the late 1940s and early 1950s.