FLOW-CONTROL AND ROUTING ALGORITHMS IN WAPSN

The performance evaluation of several routing algorithms and the combi ned effect when four levels of flow control mechanisms are operating s imultaneously in a wide area packet-switched network (WAPSN) is made b y discrete-event simulation. Both non-adaptive and adaptive routing al gorithms are discussed, and then the fixed (non-adaptive routing techn ique), the shortest-queue (isolated routing technique) and the shortes t-path (distributed routing technique) routing algorithms are selected and described for simulation in networks both with and without a mult ilevel flow control mechanism. The flow control techniques described h ere are the channel queue limit, the window mechanism and the input bu ffer limit schemes, We give results for each of the following goals: ( a) To evaluate and compare the network performance of the routing algo rithms under light, moderate and heavy load conditions during a transi ent period, subject to changes in the mean arrival rate of messages in networks both with and without a multilevel flow control mechanism. ( b) To evaluate and compare the performance of the routing algorithms d uring the transition of a network protected by an end-to-end flow cont rol mechanism to an unprotected network. (c) To evaluate the effect of varying the update interval for the adaptive routing algorithms. (d) To evaluate and compare the performance of the routing algorithms in r esponse to traffic changes or link failures in a network using a multi level flow control mechanism. (e) To develop innovative simulation mod els involving routing algorithms and a multilevel flow control mechani sm for packet-switched networks.