Fair-Efficient Guard Bandwidth Coefficients Selection in Call Admission Control for Mobile Multimedia Communications Using Framework of Game Theory

Call admission control (CAC) plays a significant role in providing the efficient use of the limited bandwidth and the desired qualityof-service (QoS) in mobile multimedia communications. As efficiency is an important performance issue for CAC in the mobile networks with multimedia services, the concept of fairness among services should also be considered. Game theory provides an appropriate framework for formulating such fair and efficient CAC problem. Thus, in this paper, a framework based on game theory (both of noncooperative and cooperative games) is proposed to select fair-efficient guard bandwidth coefficients of the CAC scheme for the asymmetrical traffic case in mobile multimedia communications. The proposed game theoretic framework provides fairness and efficiency in the aspects of bandwidth utilization and QoS for multiple classes of traffic, and also guarantees the proper priority mechanism. Call classes are viewed as the players of a game. Utility function of the player is defined to be of two types, the bandwidth utilization and the weighted sum of new call accepting probability and handoff succeeding probability. The numerical results show that, for both types of the utility function, there is a unique equilibrium point of the noncooperative game for any given offered load. For the cooperative game, the arbitration schemes for the interpersonal comparisons of utility and the bargaining problem are investigated. The results also indicate that, for both types of the utility function, the Nash solution with the origin (0,0) as the starting point of the bargaining problem can achieve higher total utility than the previous CAC scheme while at the same time providing fairness by satisfying a set of fairness axioms. Since the Nash solution is determined from the domain of the Pareto boundary, the way to generate the Pareto boundary is also provided. Therefore, the Nash solution can be obtained easily. key words: call admission control, game theory, noncooperative game, cooperative game, guard bandwidth