Abstract
This paper addresses the problem of tolerating as many faults as possible in wavelength division multiplexing (WDM) networks without the capability of wavelength conversion. The problem of finding the maximum number of faults that can be tolerated is modeled as a constrained ring cover set problem, which is a decomposition problem with exponential complexity. The Face Decomposition Algorithm (PDA) that can tolerate one or more faults is proposed. From the results, we know that the maximum number of faults tolerated can be extended from one significantly under various network topologies. © 2004 IEEE.