A Dynamic Optimization Approach to the Scheduling Problem in Satellite and Wireless Broadcast Systems

M. Raissi-Dehkordi and J.S. Baras

Number: CSHCN TR 2002-34, Year: 2002, Advisor: John S. Baras

Abstract

The continuous growth in the demand for access to information andthe increasing number of users of the information delivery systemshave sparked the need for highly scalable systems with moreefficient usage of the bandwidth. One of the effective methods forefficient use of the bandwidth is to provide the information to agroup of users simultaneously via broadcast delivery. Generally,all applications that deliver the popular data packages (trafficinformation, weather, stocks, web pages) are suitable candidatesfor broadcast delivery and satellite or wireless networks withtheir inherent broadcast capability are the natural choices forimplementing such applications.In this report, we investigate one of the most important problemsin broadcast delivery i.e., the broadcast scheduling problem. Thisproblem arises in broadcast systems with a large number of datapackages and limited broadcast channels and the goal is to findthe best sequence of broadcasts in order to minimize the average waiting time of the users.We first formulate the problem as a dynamic optimization problemand investigate the properties of the optimal solution. Later, weuse the bandit problem formulation to address a version of theproblem where all packages have equal lengths. We find anasymptotically optimal index policy for that problem and comparethe results with some well-known heuristic methods.