| 摘要 |
A system for providing television, information and data signals via a transmission network to selected subscribers, to groups of subscribers, or to all subscribers connected in common to the transmission network. An address code signal is stored at the subscriber station, and an option code signal is sent to the particular subscriber station from a head end of the network. Signals having an address portion designative of the option code or address code signal are sent down the transmission line and are translated by the subscriber station in the event the address matches the first and second code signal. Thus signals can be sent to all subscribers which have option codes designated by the address of data packets transmitted down the transmission line. These groups of subscribers can be all subscribers, individual smaller groups of subscribers, or a group consisting of even a single subscriber. The option codes can be changed from the head end at will. Consequently data can be transmitted to various subscribers designated form the head end under its complete control. The data can be control signals for controlling the unscrambling of pay-TV signals, software for operating a microcomputer peripheral, data to enable operation of a local television channel converter to facilitate selection of particular channels depending on service paid for, etc. Since the option codes can be changed from the head end, cheating of the system is inhibited and the requirement to send service personnel to each subscriber to enable the acquisition of changed services is avoided. |
