随着信息技术发展，以太网已经凭借其传输码率高、兼容性好、技术发展成熟等特点广泛应用于各项工业领域之中。但以太网协议自身存在传输延时不确定、实时性差、可靠性差等缺点，以上这些严重制约其在航空航天电子领域应用。本文通过调研航空系统机载电子设备通信的现实需求，对比分析了多种实时性以太网通信方案，提出一种环形实时以太网方案用于解决传统以太网传输过程中的实时性和可靠性问题，并将其应用于机载电子系统测试过程。 本文首先给出一种机载环形实时以太网应用框架，航空飞行器的各类电子设备作为双向接入节点（DAN）通过传统以太网物理层连接成环形拓扑。飞机上的若干传感器作为单接入节点（SAN）通过RedBox设备接入网络中，形成一个完备的环形网络，达到不增加额外设备的目的，保证数据传输系统的可靠性同时也可以实现数据传输链路的冗余。同时，通过采用IEEE1588协议实现全网时钟统一，机载网络设备按照本地配置信息，按照预定时隙进行数据传输通信，从而避免传统以太网传输过程中数据丢帧现象的发生。 本文最后利用OPNET软件对环形网络中网络节点自行建立节点域模型，并通过进程域建模，实现网络时钟同步建模和数据包丢弃流程建模，最后通过建立仿真场景，添加网络设备完成对全网实时性及可靠性方案进行的性能考核和鉴定，仿真结果验证了算法和冗余管理流程的正确性。文章最后对全网通信流程主动加入故障，验证了网络通信的可靠性和实时性。

With the development of information technology, Ethernet has been widely used in amout of industrial fields because of its excellent features such as high transmission speed, good compatibility, mature technology development and so on. However, the technology of Ethernet can not be directly applied for airborne electronic system. The protocol of Ethernet has some unignored shortcomings, the lantency of data transmission can not be forecasted and the feature of realtime transmission and the robust of system also limit the development of Ethernet applying in airborne system. In this paper, considering the demands and characteristic of aviation application and analyse many realtime protocols, the paper raises a ring-topo Ethernet scheme to overcome the weaknesses of traditional Ethernet technology such as reliability and real-time performance, and the paper apply this technology to the air-borne electronics testing process. The paper firstly proposed a airborne ring-toporealtime Ethernet application framework, the electronic equipments on board are used as double attached nodes link for a ring-topo, on which every equipment communicate with each other by reformed Ethernet protocol. The sensors on aviation are applied as single attached node, which connect into the whole net by Redundancy Box. In this way, all the electronic equipments can fit into the integrated network as while as no more equipment need be added into the net, which can also satisfy the realtimefeatures.Besides, the IEEE 1588 protocol is applied to realize the clock unity of the whole net. The equipments in the aviation net can communicate with other equipment according to the configments in the local and the fixed time slots.In this way, the phenomina of frame-loss can be avoided. The paper set up the model of ring-topo network with the software OPNET Modeler, and simulate the realtime feature and robust transmission feature.In node field, we set up two different nodes by myself, and implement the timing synchronization and data frame discarding process. Further more, we also set up a whole simulation scenario to check the effectiveness of the program.At the last of the paper, a three-level simulation model has also been set up. Inordet to testify the correctness of reliability and real-time performance, some failures of the links have also been added. The performance of the simulation also prove the practical features of this ring-topo real-time technology.