In broadcasting, each television station is given a specific channel number and bandwidth.  The broadcasting stations are able to transmit more than one independent program at the same time on the same frequency by compressing and combining them into a single signal.  This is sometimes called multicasting. 

WFPX is a television station in Fayetteville, NC that serves the Raleigh-Durham, NC television market. The station runs programming from the ION network.