一种用于SpaceWire网络的混合路由机制设计*

针对星上系统总线多元性导致的星载网络接口和协议不能标准化的发展瓶颈,本文基于SpaceWire总线协议,通过将静态路由(时间触发)与动态路由(事件触发)机制结合,实现了控制数据和载荷数据共用网络。静态路由完全遵循SpaceWire-D协议,在保证确定性传输的同时,通过启发式调度算法首次实现了多时间窗并行调度,并提出利用最大公约数法设计时间窗,以提高网络吞吐量；动态路由通过对随机事件和载荷数据分配优先级,实现传输路径冲突时对紧急任务的优先处理。最后在OPENT中搭建网络系统仿真模型,对所提出的路由机制进行了仿真。实验结果表明,静态路由时段网络吞吐量较现有调度算法有明显提高,动态路由实现了紧急事件优先传输。

Design of a hybrid routing mechanism for SpaceWire networks

Aiming at the bottleneck of the non-uniform interface and protocol of spaceborne network caused by multiple bus standards, the time-triggered static routing and event-triggered dynamical routing are combined based on the SpaceWire bus protocol, to make control data and payload data share the same network. The static routing mechanism abides by the SpaceWire-D protocol to ensure deterministic data delivery, in which heuristic scheduling algorithm is adopted to realize multi-slot schedule for the first time, and the time-slot is designed by using greatest common divisor to improve the throughput. And the dynamical routing mechanism can insure the critical random event be processed preferentially when transmission routes conflict, by allocating priority levels to random event and payload data. In addition, a simulation model for the network system is set up in OPNET to evaluate the proposed routing mechanism. And the results show that the throughput of the network is improved significantly during static routing time as comparing with the existing scheduling algorithm, and different transactions can be processed according to their priority during the dynamical routing time as expected.