一种应用于临近空间通信网络混合业务的MAC协议

该文提出了一种基于修改PRMA协议用于支持混合业务的临近空间通信网络MAC协议。主要对PRMA协议中的帧时隙进行最优划分组合，每帧由100个时隙组成且分为两部分，前m个时隙用于传输视频业务和数据业务，后n个时隙用于传输语音业务。通过对时隙最优划分，业务分离和业务优先级判断，系统很好地支持了语音，数据和实时变化比特速率(rt-VBR)视频混合业务。最后对数据业务包平均时延，语音和视频业务丢包率以及信道利用率等性能参数进行仿真评估，证明该协议在保证各种业务服务质量(QoS)的同时也对提高信道利用率起着重要的作用。得到了最优视频业务预留时隙数m=36和85%的信道利用率。

A Novel MAC Protocol for Mixed Traffics in Communication Network in Near Space

Abstract：A novel MAC protocol which was able to support data, voice and rt-VBR video traffics based on PRMA protocol was proposed for communication network in near space. PRMA frame comprised in 100 slots was divided into two parts, one part, namely m slots are allocated for rt-VBR video and data traffics. The other part, namely n slots are allocated for voice traffic. The proposed MAC protocol had good ability to support mixed traffics by means of optimized combination of slots in a frame, traffic separation and traffic priority. Three performance parameters: voice and video packet loss probability, average delay of data packets and channel utilization were analyzed in simulation. The simulation showed that the proposed MAC protocol had advantages on increase of channel utilization with the guarantee of quality of service. Finally the optimized reservation time slots for rt-VBR video traffics m=36 and maximum channel utilization of 85% were achieved. Key words：near space; media access control; packet reservation multiple access; mixed traffics; packet loss probability; average time delay; channel utilization