针对随机竞争预约机制在网络负载较重时预约性能恶化导致卫星信道利用率下降的问题,提出了一种适用于卫星网络信道预约的统计预测机制,该机制在对预约时隙(slots for reservation,SR)可用度进行多等级划分的基础上,利用一致最小方差无偏估计和Faulkenberry理论计算下一帧SR可用度的预测区间,根据 Markov模型的转移概率矩阵和SR可用度出现次数的频率估计,对下一帧内信道SR 的可用度进行精确预测,用户终端根据预测结果动态调整预约请求的发送概率。理论分析与仿真结果表明,该机制具有较好的适应性和有效性,预测精度得到了较大提高,减小了信道预约冲突概率,提高了卫星信道利用率。
A novel channel reservation statistical prediction mechanism based on statistical analysis is pro-posed to solve the problem of performance deterioration of the random competition reservation mechanism when the load becomes heavy,which decreases the channel utilization of satellite network.The predication interval which the availability of slots for reservation (SR)in the next frame possibly belongs to,is calculated by uni-formly minimum variance unbiased estimation and the Faulkenberry theory based on multi-availability division of SR.The precise predication of prospective availability of SR is obtained according to the transition probability of the Markov model and frequency estimation of SR availability appearance times in history information.User ter-minals adj ust their transmitting probability of reservation requests according to the availability predication of SR in the next frame.The results of theoretical analysis and simulation both indicate that the performance of appli-cability and availability of the novel mechanism is good,while the predication accuracy has been improved obvi-ously.The collision probability of reservation requests has been decreased and the channel utilization has been enhanced.