多媒体CDMA蜂窝网络中联合退避缓存及速率自适应的呼叫接纳控制策略

Joint Rate-adaptive and Backoff Waiting Call Admission Control for Differentiated Services in CDMA Cellular Networks

资源管理和呼叫接纳控制作为未来蜂窝网络的核心管理模块,能为移动用户提供具有QoS保证的多媒体应用并实现无线资源的有效利用.针对多业务CDMA蜂窝网络,结合非理想功率控制下的容量定义,提出退避缓存与自适应速率调控相结合的呼叫接纳控制策略.其中退避缓策略采用请求呼叫主动退避的思想,有效降低阻塞率;自适应速率调控策略则采用业务用户双重分级的思想,确保用户公平性的同时实现平稳的QoS.仿真结果表明,该策略可以自适应地保证各类业务的QoS要求,提高业务间的公平性和系统资源的利用率.

Resource allocation and call admission control （CAC） are key management functions in future cellular networks, in order to provide multimedia applications to mobiles users with quality of service （QoS） guarantees and efficient resource utilization. This paper proposes a novel call admission control for multi-services CDMA cellular network, which consider the capacity in the condition of non-ideal power control and work in conjunction with rate adaptation and baekoff waiting schemes. The backoff algorithm, in which the rejected calls choose the backoff delay randomly and wait for another access opportunity, decreases the blocking probability effectively. Also, rate adaptation strategy, using dual classification for services and users, not only maintains the fairness of users, but also guarantees the smooth degradation of quality of service （QoS）. Simulation results have demonstrated that the proposed adaptive CAC scheme guarantees the QoS of different traffic efficiently, and improve the resource utility significantly.