An evaluation of distributed wavelength provisioning in WDM optical networks with sparse wavelength conversion

Distributed wavelength provisioning is becoming one of the most important technologies for supporting next-generation optical networks. This paper describes the evaluation of the performance of distributed wavelength provisioning in wavelength-division-multiplexing (WDM) optical networks with sparse wavelength conversion (i.e., where wavelength conversion is available at only a subset of network nodes). Using the well-known destination-initiated reservation method as a case study, a highly accurate analytical model supported by comprehensive simulation validation is proposed. Both analytical and simulation results show that, in optical networks with distributed wavelength provisioning, sparse wavelength conversion still helps to significantly lower the connection-blocking probabilities. However, unlike that in centralized wavelength provisioning, sparse wavelength conversion may not easily achieve nearly the same performance as that of full wavelength conversion, especially under light traffic loads. This paper evaluates how the potential contribution of sparse wavelength conversion depends on different factors, such as the number of wavelength converters, the number of wavelength channels per fiber, the burstiness of traffic loads, and the network size, and discusses the influence of the signaling scheme.