Patent ID: 6901605

Claim:
A cable broadcasting system comprising: a center equipment, including a broadcasting equipment for transmitting broadcast signals on a transmission line, and a controller for transmitting command signals for controlling distribution of the broadcast signals to broadcast signal receiving terminals through the transmission line, and at least one receiving district, each receiving district including a plurality of tap devices connected from the transmission line for distributing the broadcast signals from the transmission line to the broadcast signal receiving terminals, and a district power supply connected from a power source and providing a power signal through the transmission line to the tap devices of the receiving district, wherein the command signals are separate and independent from the power signal, each tap device including at least one switchable tap path for distributing the broadcast signal from the transmission line to corresponding broadcast signal receiving terminals, at least one control relay in each tap path for controlling connection of the tap path to the broadcast signal receiving terminal, a tap control connected from the transmission line and responsive to the command signals for controlling the control relays according to the command signals, and a tap device power supply connected from the power signal on the transmission line and providing power to the tap device, wherein in a sequence of command signals transmitted by the center equipment controller to control the control relays of a plurality of tap paths, successive command signals are transmitted to different receiving districts, wherein the controller of the central equipment transmits a command signal to a receiving district having at least one tap device to which a command signal is to be transmitted, transmits a command signal to a receiving district which has not received a command signal in a proceeding transmission of a command signal and which has at least one tap device to which a command signal is to be transmitted, and repeats the transmission of command signals as necessary to provide at least one command signal to each tap device which is to receive a command signal, thereby limiting the tap device switching operation executing in the receiving district to one tap device per receiving district such that a power demand to the district power supply due to the tap device switching operations will remain below a predetermined limit.