1983 Reports

Protocol Architecture of a Tree Network with Collision Avoidance Switches

Suda, Tatsuya

In this paper we propose a tree network with collision avoidance switches and discuss its protocol architecture and performance. In the tree network, collision avoidance switches are connected by full duplex transmission lines and form a rooted tree topology with stations at its leaves. A station transmits a packet whenever it has a new one. The collision avoidance switch allows packets to go through when it is idle, and blocks them when busy; thus collisions caused by simultaneous transmissions of packets are avoided. Blocked packets are retransmitted by the sender, while unblocked packets, after having climbed up the tree to an appropriate height, are broadcast down to a subset of stations (local broadcast). Packets are broadcast locally in order to maximize the number of concurrent transmissions. In addition, collisions among packets are completely avoided, hence, the network is highly efficient in performance. Performance analysis for simple case is shown, and the mean packet transmission delay and throughput are obtained.