Collision detection technique for multiple access protocols on radio channels

Abstract

The carrier sense multiple access with collision detection protocol (CSMA/CD) has already gained wide commercial acceptance and is used in cable and optical-fibre based local computer networks. However, its use in radio channels is inhibited by the difficulty of sensing remote carriers in the presence of local transmission. A new collision detection technique for radio channels called time-split collision detection is introduced. Collision is detected by a sequence of carrier sense, preamble transmission and carrier sense again at the beginning of a packet transmission. Throughput analysis of a new multiple access protocol using time-split collision detection is also presented. The proposed protocol has throughput performance between those of the CSMA and CSMA/CD.