RANDOM ACCESS PACKET SWITCHED LOCAL COMPUTER NETWORK WITH PRIORITY FUNCTION.

A description is given of a local computer communication network called ″Priority Ethernet″ which modifies the original Ethernet to be capable of transmitting important information without much delay even when the channel is heavily loaded. This modification is realized by adding to a packet a preamble signal of which duration is proportional to its priority level. By incorporating this priority function, the highest priority packet of colliding ones is always successfully transmitted. Since this priority function is realized by a very little increase of hardware, the proposed system still keeps such key features of the original Ethenet as simplicity, reliability and extensibility. The principle of the scheme, the throughput-delay analysis and the brief description of a model system are presented.