Mean waiting time approximations in cyclic-service systems with exhaustive limited service policy

Motivated by token-passing protocols in LANs, a system of multiple queues, attended by a cyclic server, is considered. The server will switch from the i^th queue to the next when either K_i customers are served consecutively or the queue is empty, whichever comes first. Using the pseudoconservation laws, an approximation method is developed to obtain the mean waiting time for each queue. The performance of this approximation is shown to be more robust and accurate then previous heuristic approximations. Further, it is shown to be suitable for modeling token-passing LANs