QoS routing with wavelengths conversion and call admission connection in DWDM networks

In a dense wavelength division multiplexed (DWDM) network, a connection must be established along a route using a common wavelength on all of the links along the route. This constraint may be removed by the introduction of wavelength converters, which are devices that take the data modulated on an input wavelength, and transfer it to a different output wavelength. Wavelength converters improve the network blocking performance as well as the QoS and routing management. This paper provides a review of the conclusions drawn from these investigations. We also present an approximate analytic model to allow flexible wavelengths assignment policies by virtue of optical layered approach.