BULK ARRIVAL RETRIAL QUEUE WITH FLUCTUATING MODES OF SERVICE, IMMEDIATE FEEDBACK AND SERVER VACATION

Batch arrival retrial queue with immediate feedback is considered. Server provides M modes of service to the customers. If an arriving batch of customers finds the server free, one of the arrivals chooses any one of the M modes of service immediately and the rest join the orbit. Otherwise all the arriving customers join the orbit. At a service completion epoch, the unsatisfied customers opt for re-service. After completion of each service, the server departs for a single vacation of arbitrary distributed length according to Bernoulli schedule. Analytical treatment of this model is obtained by the supplementary variable technique. Stochastic decomposition law is verified. Numerical results are presented. Keywords: Retrial Queue, Fluctuating Modes, Immediate Feedback and Vacation