| 摘要 |
A multiple services system using telephone lines to supply various data services to subscribers, including alarm surveillance, meter reading, energy management and digital data service, provides a multi-conductor subscriber bus at the subscriber premises for selective connection of plural data service terminals to the system and a switching communication controller at the central office which acts as a concentrator for the transmission of alarm, meter reading and control signals between the subscriber data system and a central control system, while acting as a switch for the connection of the subscriber data system to a data service system for transmission to the subscriber of digital video display data on request. The transmission over the telephone lines is transparent to normal telephone service and all communications within the system, including those on the subscriber bus, are effected in accordance with a predetermined link control protocol.
|
