Request Contention and Request Polling for the Upstream Media Access Control in ATM Access Networks
Joachim Charzinski · 1998
This paper presents a simulation study comparing different mechanisms used in the upstream channel of ATM access networks. In request polling , status information from the access stations is transmitted periodically in minislots dedicated to each access station. In request contention ,the access stations use a contention based multiple access scheme with a multi-slot stack contention resolution algorithm for random access to the minislots. In addition, in both cases request information is piggy-backed to upstream ATM cells. In a simulation study, request polling and request contention are compared using the same system parameters. It is shown that (1) the optimum stack parameter is greater than three if the round trip delay in the system is taken into account and (2) under most conditions request contention produces longer mean transfer delays and delay quantiles than request polling.