军用车载光纤数据总线的拓扑研究

研究和量化了拓扑和访问耦合器对光纤网络物理性能的影响。针对双总线形、星形、环形和双环形四种光纤网络拓扑,比较它们的光纤需求长度、平均传播延迟、传输衰减、最大比特率及容错。结果表明:在100个节点情况下,星形拓扑需要的光纤长度是双环形的3.8倍,而双环形的平均传播延迟是星形的3.3倍;双总线形的传输衰减最大,在10个节点情况下,要求接收器的动态灵敏度达24dB;假设使用垂直腔面激光器和渐变折射率多模光纤,使用容错耦合器导致最大比特率性能降低,双总线形和星形的最大比特率与节点数相关。这些结果可为选择光纤数据总线拓扑和访问耦合器提供参考。

Topology analysis of the optical fiber data buses for military vetronics

The physical performance imposed by topologies and access couplers in optical fiber data bus for military vehicle is analyzed.The comparison is in term of fiber required,average propagation delay,transmission loss,max bit rate,fault tolerance among four type topologies included bus,star,ring and dual ring.The results show that for 100 nodes,the star topology requires 3.8 times as much as fiber as a dual ring,but the average propagation delay of a dual ring is 3.3 times that of the star.For 10 nodes,the receiver dynamic range must be greater than 24 dB.If VCSEL and graded-index multimode fiber were adopted,the maximum bit rate reduces due to the fault tolerant access coupler used and depends on the number of nodes in the dual unidirectional bus or star topology. These results can provide reference for choosing topology and the type of access couplers that may be used in optical fiber data bus.