Document Type


Date of Award

Spring 5-31-1991

Degree Name

Master of Science in Electrical Engineering - (M.S.)


Electrical and Computer Engineering

First Advisor

Constantine N. Manikopoulos

Second Advisor

George Antoniou

Third Advisor

MengChu Zhou


Ordinary service and exhaustive service are two major alternatives of scheduling policies considered in providing access to token ring networks. Results to date have shown that exhaustive service results in more delay to lightly loaded stations in asymmetric traffic while ordinary service wastes time in circulating the token after each transmission. This work presents a new token passing protocol, called adaptive service, in which the token holding time is dynamically changing; in this way, it provides a fair compromise between exhaustive and ordinary service. The simulation results show that in asymmetric traffic, adaptive service gives improvement on the local delay compared with exhaustive service and gives improvement on global delay compared with ordinary service. Also for symmetric traffic, it gives improvement compared to ordinary service. Moreover, it always provides superior throughput performance over ordinary service.