The Research On Availability Of Networks Based On Fuzzy Theory

For the evaluation of the network availablity,the basic parameters of communication infrastructures e.g.failure rate and repaired time,always have a great influence on the evaluation results.The parameters are not precise and can be expressed with fuzzy number. Firstly,the availability models of SDH ring networks and WDM mesh networks were built by Reliability Block Diagram.Then,based on description of stochastic events and fuzzy events using probabilistic method and fuzzy set theory,the evaluation method of fuzzy availability in optical fiber communication networks is presented.Fuzzy availability indexes are obtained by means of fuzzy calculation.Finally,the availability of actual optical fiber communication networks was analyzed and calculated,and the fuzzy result is compared with the precise result.Because the fuzziness in parameters,failure rate and repaired time is described by fuzzy calculation,the actual situation of network availability can be reflected.