RANDOM ACCESS MULTIPOINT DATA COMMUNICATION SYSTEM

摘要

A random access multipoint data communication system comprises a central station and a plurality of remote stations. A multiple access channel is established from the remote stations to the central station and a broadcast channel is established from the central station to the remote stations. The central station generates a timing signal for causing each of the remote stations to define commonly shared time slots on the multiple access channel. Each remote station transmits data on a randomly determined time slot of the multiple access channel. The central station periodically and sequentially interrogates the remote stations to return an acknowledgment and processes the returned acknowledgments to determine the presence of a malfunctioning remote station. To avoid data collision, the central station specifies an idle time slot on which the interrogated remote station is requested to send the acknowledgment.