宽带卫星IDMA系统的自适应多业务接纳控制算法

An Adaptive Admission Control Algorithm for Multi-service IDMA-based Broadband Satellite Communication Systems

针对宽带卫星信道环境的特点和IDMA的技术优势,提出了基于IDMA的自适应多业务接纳控制(call admission control)算法。在此接纳控制算法中,引入缓存机制和自适应速率调整策略。其中,缓存策略依据各类业务的时延特性,将暂时无法接纳的用户放于队列中等待资源空闲接入,进而有效地降低呼叫阻塞率或中断率;自适应速率调控策略则在用户发生拥塞时,根据业务用户优先级递增的顺序,对于已经接纳的用户,采取中低优先级速率降级处理的手段,在用户公平性的原则下,实现平稳的QoS。

Considering qualities of satellite channels and advantages of IDMA technology, an IDMA-based adaptive admission control algorithm is proposed. In the call admission control scheme, a buffer mechanism and an effective rate adaptation scheme are employed. The buffer mechanism therein, contraposing the delay characteristic of each user, keeps the temporarily unaccepted users stay in the buffering queue until idle resource emerges for effective decrease in the probability of call blocking and outage. In the meanwhile, when the congestion between users occurs, the effective rate adaptation scheme degrades the rate of accepted users with low-mid priorities in accordance with the corresponding ascending order of priorities, achieving stable QoS under the principle of user fairness.