| 摘要 |
<p>IMPROVED COMMUNICATIONS INTERFACE A data link controller and an interface specification for network interface modems is disclosed. A specific modem is described for a client data processing unit for use in a broadband local area data network with collision avoidance protocol. The controller immediately acknowledges receipt of a perfect data packet independently of the processing unit without going through a line acquisition protocol. Each received acknowledgment packet is placed in a transmit buffer at a known location relative to the data packet which was just transmitted, for which it is an acknowledgment so that each acknowledgment packet may be located in less time by the processing unit. Also disclosed is an improved modem for a single frequency, modulated RF carrier local data network for a distributed data processing system and a method for line acquisition and contention resolution. The protocol in this method is implemented by a modem controller which causes the receiver section to listen for interference beating, i.e., changes in amplitude on the line which indicates another unit is requesting the line, to determine when the line is busy. If a contention is found, it is resolved using a random delay and retry protocol.</p> |
