Optimal design of WDM ring networks via resource-balance

Performance and cost are two most important factors that affect the scalability of a WDM network. This study addresses two issues. One is to determine what is the best possible performance, and more importantly, how to achieve it with the given resources. The second is to determine which resource is insufficient, which is excessive, and how to balance them. We illustrate the principle by focusing on the problem of establishing complete connections, also known as all-to-all personalized communications, in a WDM ring. We show that there is an optimal value of the number of wavelengths for a given number of tunable transceivers per node and vice versa. In particular, the latter does not need to exceed 12 in an arbitrarily large ring.