Performance analysis of an adaptive token bus protocol

The authors study the performance of an adaptive token-passing bus protocol where only active stations participate in the token passing, and therefore make up the logical ring. A station is active over an interval of time if during that interval data are generated at the station to be sent over the network. The size of the logical ring thus varies randomly according to the traffic intensity of the system. Existing analytical results for token-passing systems assume a fixed number of stations, which will take part in the token passing regardless of whether a station is active or not. An approximate analytical model is provided for a token-passing system where the effective size of the ring changes dynamically according to the network traffic.>