卫星导航系统由空间段、地面段和用户段3部分组成。地面段由主控站、监测站、注入站和与之互联的高性能通信 网络组成,承担空间段导航的控制和星座管理,为用户安全可靠地使用整个系统提供保障服务,而高性能的互联通信网络 则为地面段的数据传输提供了具有服务质量保证的平台。文中通过OPNET仿真软件,针对地面段中数据传输交换的通 信质量管理问题,根据各站发送的各类信息重要性不同的特点,建立基于帧中继技术和基于帧中继甚小地球站卫星通信 网络数据传输网络场景,对数据是否采取优先级传输进行仿真测试,通过数据分析,为高性能的卫星通信网络优化部署提 供有意义的建议。

The satellite navigation system consists of a satellite constellation transmitting navigation signal, a ground segment for monitoring the constellation and for disseminating the navigation messages through the navigation signals to the user receivers. The ground segment is consisting of control centers, sensor stations and Up-link stations, interconnected with global communications networks, which need to fulfill strict quality of service (QoS) requirements in terms of availability and latency. This paper will present the results of simulations using OPNET simulation tool, in order to determine the factors impacting the QoS requirements and capacity of these global communications networks. Under the work presented, a frame relay only network and a mixture of frame relay and very small aperture terminal (FR&VSAT) satellite network have been simulated. Performance analyses have been carried out in order to determine whether to communicate with or without prioritized data.