System for controlling communications on a cable television network

摘要

A system for controlling a cable television network includes a head end, a plurality of addressable external control units having subscriber converters located off the subscriber's premises, and one or more subscriber devices located on the subscriber premises for communicating with associated external control units. The head end can selectively and rapidly poll the external control units for information on a general or on a priority basis. Information is transmitted to the head end from the external control units on any of a plurality of reverse communication channels under control of the head end. External control units use a two-part polling scheme to poll a plurality of associated drop cables, and individual subscriber devices attached to the drop cables. The polling rapidly identifies subscriber devices desiring to communicate with the external control unit.