NBC has kicked off its plan to operate all its O&O stations from three hubs with the switch last week of the master control and traffic functions of WVTM-TV Birmingham, Ala., to co-owned WTVJ-TV Miami. WVTM-TV is the first of the four stations that will eventually be operated from the Miami hub. NBC, aiming at increasing operational efficiency, will create a New York hub with seven stations in late spring, followed by a two-station Los Angeles hub. WTVJ was selected as the initial hub because of its digital makeover two years ago. "It opened our eyes," said Jay Ireland, president of NBC television stations.