With automated alarm monitoring a remote operator can listen or observe via closed-circuit television to a duress signal on protected property. Transmission using digital communications offers a variety of capabilities including system arming and disarming, force-arming, shunting, diagnostics, and changing functions or performing special functions. Long-range radio technologies also are growing in availability and offer an alternative to dependence on telephone lines for signal security. Another alternative, derived-channel technology, can continuously poll an alarm system over existing telephone lines at frequencies below voice grade. It requires only a subscriber terminal unit at the protected site to access the telephone line and typically costs less than $10 per month. However, this technology is dependent upon telephone companies' willingness to invest in it. Additional technologies that should become increasingly available are alarm monitoring via cellular based communication systems, microwave-to-satellite, and integrated services digital networks. Illustrations.