IFF: a novel wavelength assignment scheme for WDM optical networks

This paper investigates the performance of few wavelength assignment schemes used in wavelength-routed WDM networks under dynamic traffic environment. The paper focuses on networks operating under wavelength continuity constraint, in which the same wavelength must be assigned to all the links of the chosen route. We compare the performance of some of the wavelength assignment schemes used and propose a new scheme that performs better in terms of blocking probability, especially as the number of offered wavelengths per fiber increases. This novel scheme avoids assigning the same wavelength to multiple connection requests concurrently to reduce blocking caused by reservation conflicts between simultaneous connection requests. The improved first fit (IFF) algorithm is based on the first fit wavelength assignment scheme, with a different starting search point for every new connection request.