【作者】 沈骏； 朱弘飞； 依那； 金野；

【Author】 SHEN Jun, ZHU Hongfei, YI Na, JIN Ye (Satellite & Wireless Communication Lab, Peking University, Beijing, 100871, China)

【机构】 北京大学卫星与无线通信实验室；

【摘要】 卫星通信发展的趋势要求LEO、MEO和GEO卫星系统都提供宽带综合业务的支持能力,在最大化卫星资源利用率的同时支持综合业务的QoS需求。在此需求下,不同轨道高度系统必然需要采用特定的协议体系才能具有较好的系统性能和QoS支持能力。本文主要针对卫星通信系统中较为关键的MAC协议在LEO、 MEO和GEO中的系统性能和QoS支持能力进行了分析,并在此基础上提出了面向优先级的混合MAC协议 (PODA)。仿真中,通过筛选与比较,最终确定了在LEO,MEO和GEO中各自适用的一组MAC层协议;而后进一步发现PODA协议具有较高的系统吞吐量,良好的端到端特性,能够优先保证高优先级业务的QoS,因此本文提出的PODA协议适用于高中低轨卫星通信系统,特别是系统负载较重的情况下。PODA协议所属的按需分配和及其混合协议势必成为未来卫星通信发展的方向。更多还原

【Abstract】 The central features of the future mobile communication systems are the provisioning of high-speed data transmissions and a heterogeneous mix of traffic classes, ranging from traditional telephone calls to video and data services. For effective delivery of these services, the network must satisfy some stringent quality-of-service (QoS) metrics, defined typically in terms of maximum delay and/or minimum throughput performances. Mobile satellite systems (including LEO, MEO and GEO) will be fully integrated with the future mobile communication systems, playing important roles as backbones or access satellites, to provide ubiquitous global coverage to diverse users. The challenges for future broadband satellite systems, therefore, lie in the proper deployments of state-of-the-art satellite technologies to ensure its QoS frameworks, while achieving, to the extent possible, efficient use of the precious satellite link resources. To let the LEO, MEO, GEO satellite systems which are in different altitude support integrated services, the most prominent technologies such as MAC (multiple access control) layer technique is then discussed in the context of the satellite systems. After theoretical analysis and simulation, some specific MAC protocol were suggested for the LEO, MEO and GEO to support varied QoS services, so the thought of combining different Satellite Systems can really come true, and this is also the conclusion of this article.更多还原