AbstractsComputer Science

In real world retrial queues have been widely used as models for newlinestochastic phenomenon such as telephone switching systems newlinetelecommunication networks and computer systems Retrial queueing systems newlineare characterized by this particular feature arrivals who find the server busy newlineleave the service area and join the retrial group to try again for their requests newlinefor service This study discusses retrial queueing models with feedback newlineserver breakdowns vacations and control policies on arrivals The proposed newlinemodels of this research work have been theoretically developed and newlinenumerically justified newlineThe thesis starts with introductory concepts of retrial queues It also newlinepresents a brief survey of some relevant existing research work on retrial newlinequeues newlineIn the proposed work six different retrial queueing models have been newlineAnalyzed For all the models various performance measures some special newlinecases and particular cases are discussed Numerical illustrations are also newlineprovided for all the models newlineA single server non Markovian retrial queue with working vacation newlineand constant retrial policy is analyzed first If the server is busy at the arrival newlinetime the customer joins the orbit to repeat its request later On the other hand newlineif the server is idle then the arriving customer begins its service immediately newline newline newline newline%%%reference p182-195.