Scheduling broadcasts with deadlines

Abstract

We investigate the problem of scheduling broadcasts in data delivering systems via broadcast, where a number of requests from several clients can be simultaneously satisfied by one broadcast of a server. Most of prior work has focused on minimizing the total flow time of requests. It assumes that once a request arrives, it will be held until satisfied. In this paper, we are concerned with the situation that clients may leave the system if their requests are still unsatisfied after waiting for some time, that is, each request has a deadline. The problem of maximizing the throughput, for example, the total number of satisfied requests, is developed, and there are given online algorithms achieving constant competitive ratios. (C) 2004 Elsevier B.V. All rights reserved.