Queuing Theoretic Models for Multicasting Under Fading

We consider a wireless system with one server and several users making requests from a fixed library of files. The request process from each user is assumed to be an independent Poisson process. The pending requests at the server are queued in a special queue called multicast queue. In this queue, the requests for the same file are merged. A transmission from the server is received by all the users who have requested the file. The channel from the server to each user experiences block fading. We propose several queuing and service strategies for this system and compare their mean response time. We show that our multicast queue significantly out-performs the usual first-in-first-out (FIFO) queue with no merging. We also propose a power control policy to further improve the performance.