关键词: 无向双环网络, 最优路由构图, 扩展路由构图, 容错路由, 故障点封闭区, 故障点逃逸区

Abstract: It is important to assure communication among nodes in networks when fault nodes occur. Assigning nodes of bidirectional double-loop network to Cartesian coordinates by the minimum distance visiting mode forms an optimum graph [CG(N;±r,±s)]. By this graph according to whether source node and destination node lie in horizontal or vertical coordinate and the amount of fault nodes around them, the concepts of closing areas and escaping areas of faulty nodes are proposed. When escaping areas occur, there exists optimum routing paths from source node to destination node. As for the situation of there exists no optimum routing that arising from closing areas of faulty nodes, adding equivalent nodes to form an extended optimum graph [ECG(N;±r,±s)] to seek fault-tolerant routing. The algorithms of optimum Cartesian coordinates graph, extended Cartesian coordinates graph and fault-tolerant routing are proposed and simulated by programming.

Key words: bidirectional double-loop networks, optimum routing graph, extended routing graph, fault-tolerance routing, closing areas of faulty nodes, escaping areas of faulty nodes