DOUBLE SEARCH SELF-HEALING ALGORITHM AND ITS CHARACTERISTICS

The requirements of today's communication networks are changing rapidly with the introduction of high-capacity transmission links and the increased amount of data traffic, thus fast restoration from failures is of increasing importance. To meet this requirement, self-healing algorithms, which are distributed algorithms based on autonomous control at each node, are discussed. The conventional self-healing algorithms called single-search self-healing algorithms have the following problems: (1) the self-healing process for bidirectional path failure has not been investigated; and (2) at large search area is affected by restoration messages. To solve these problems, this paper proposes and evaluates the restoration characteristics of a new self-healing algorithm called the ''double-search self-healing algorithm.'' The results indicate that the proposed algorithm can restore failed bidirectional paths faster and find alternate paths more effectively than conventional self-healing algorithms. To evaluate the restoration characteristics, an SDH network model based on existing telephone network data in Japan also is constructed.