星载互连并行Clos网络

Onboard interconnected parallel Clos-network

针对空间辐射环境造成的星载交换可靠性下降的问题,提出了一种互连并行Clos(interconnected parallel Clos,IP-Clos)网络以抵抗空间辐射造成的交叉点故障和交换单元故障。IP-Clos包含多个Clos平面,相邻Clos平面通过平面间连接进行互连。通过采用平面间连接,每一级都存在多条路径到达下一级。理论计算表明,相比并行Clos网络,IP-Clos网络增加了交换单元间的连接数量,在交叉点故障和交换单元故障下具有更高的可靠性。数值分析表明,对于同步轨道(GEO)卫星,采用宇航级FPGAs实现的IP-Clos网络在交叉点故障下的平均失效时间大于2.1×105 d,在交换单元故障下的平均失效时间是6.86×103 d。

Onboard switches in harsh space radiation environments can suffer serious reliability degradation.An interconnected parallel Clos（IP-Clos）network was developed to resist crosspoint faults and switch element faults.The IP-Clos consists of multiple Clos-network planes.Adjacent Clos-network planes are connected by inter-plane links to create multiple paths in each stage connecting to the next stage.Theoretical analyses demonstrate that the IP-Clos network has better reliability than parallel Clos networks for both crosspoint faults and switch element faults at the expense of the link overhead between switching elements.Numerical results indicate that the mean time to failure（MTTF）of an IP-Clos network in a geosynchronous orbit（GEO）satellite with space-grade field programmable gate arrays（FPGA）for crosspoint faults is more than 2.1×105 d.The MTTF for switch element faults is 6.86×103 d.