Dynamic wavelength allocation in all-optical ring networks

We focus on wavelength allocation schemes for all-optical WDM ring networks. For an N node network we characterize the traffic by its load L_max (the maximum number of lightpaths that share a link) and do not assume knowledge of the arrival/departure processes. We prove that shortest path routing produces a routing which has at most twice the load of the optimal solution. We show that at least 0.5 L_max log₂N+L_max wavelengths are required by any algorithm in the worst case, and develop an algorithm which requires up to 3 L_max log₂N wavelengths. For the case when the load is high and blocking is necessary we present an improved algorithm