Harmonically Related Carrier is a standard used by Cable TV broadcasters to assigning frequencies to channel numbers. Cable services can use Standard, HRC, or IRC channel frequency. HRC and IRC uses channels 1-125, STD uses 2-125 channel assignments. Contact their Cable TV provider for the standard they use. Impulse Pay-Per-View: Conditional access service where the user is able to buy a particular program on a last-minute decision.