A framework for bandwidth degradation and call admission control schemes for multiclass traffic in next-generation wireless networks

摘要

The next-generation wireless networks need to support a wide range of multimedia applications with limited radio resources like bandwidth. In this paper, we propose a novel integrated framework for bandwidth degradation and call admission control (CAC) for multiclass real-time multimedia traffic in such networks. To increase the total carried traffic in an overloaded (saturated) wireless system, some of the ongoing calls in our framework are allowed to operate under a degraded mode, thereby releasing wireless channels that can be used to accommodate new calls, however, at the cost of user satisfaction. Indeed, an increase in carried traffic (i.e., provider's revenue generation) and user's quality-of-service satisfaction are two conflicting goals in a bandwidth allocation scheme. The proposed framework adequately models this tradeoff by introducing the negative revenue (i.e., loss) from bandwidth degradation, and finding the optimal degradation and admission policies that maximize the net revenue. When there is a mixture of real-time and nonreal-time calls in the system, the former are given preemptive priority over the latter, which are buffered for future admission in case of preemption. A channel sharing scheme is proposed for nonreal-time traffic and analyzed using a Markov modulated Poisson process-based queueing model. Detailed simulation experiments are conducted to validate our proposed framework.