Method and apparatus for preventing message collisions in a half-duplex communication system

Abstract

In a half-duplex communication system in which additional delays in the communication channel may cause a message collision between a message and a response, a timer based collision prevention circuit is utilized to prevent the message collision. The collision prevention circuit determines if the message transmitted by a communication device will be repeated. If the message is to be repeated, the collision prevention circuit sets a countdown collision timer to a predetermined period of time shorter than the shortest repetition interval of the repeated message. A response is only sent to the communication device if the collision timer has not expired. If the timer expires, the collision prevention circuit waits for the message to be retransmitted by the source device before sending the response to the communication device.

Dependencies are inferred from the claim text.