A Flexible Set of Methods for the Analysis and Optimization of CRMA-II Cycle Time and Scheduling Mechanisms
Abstract
In a lot of previous papers the excellent throughput and fairness characteristics of the CRMA-II (Cyclic Reservation Multiple Access) Gbit/s LAN and MAN Medium Access Control protocol have been shown by extensive simulations. Also new mechanisms and features have been proposed to further enhance the performance of CRMA-II. The purpose of this paper now is first to give new approximate analytical expressions for the distributions of the internal system variables of CRMA-II. The derived methods are then used to detect and correct two sources of possible deadlocks in the protocol itself and in aproposed enhancement. Since the delay-oriented aspects of how fairness is achieved within CRMA-II networks are mostly determinded by the structure of the scheduling cycles and their duration T an approximation for the distribution of T is derived by analyzing its constituting processes and effects. As a result guidelines are given concerning the necessary calculation speed of the CRMA-II scheduler and an adaptive marking method is proposed to further potimize the scheduling process.
Year
1994
Reference entry
Kirstädter, A. A Flexible Set of Methods for the Analysis and Optimization of CRMA-II Cycle Time and Scheduling Mechanisms
Report, Technische Universität München, June 1994