On Wavelength-Routed Networks With Reversible Wavelength Channels

Abstract

We observe that the performance of wavelengthrouted (WR) networks often suffers from asymmetric traffic and network traffic patterns differing from the original design plans. WR networks with a fixed number of channels in a given transmission direction are inflexible. Therefore, we propose reversible wavelength channels. Like a reversible lane in highway systems, a reversible wavelength channel has the flexibility of its transmission direction being configurable at the setup of a lightpath. So far reversible wavelength channels have not been discussed in WR networks even though we observe that most of the required technologies are already available. In this paper, we discuss all the required technologies for implementing reversible wavelength channels in WR networks. We demonstrate that reversible wavelength channel can provide significant performance improvement for WR networks when the traffic is asymmetric. Even if the traffic is symmetric, we also have nontrivial performance improvement with reversible wavelength channels, i.e., the blocking performance of WR networks with reversible wavelength channels will be similar to that of normal WR networks with doubling the number of fibers per link. Different implementation approaches for reversible wavelength channels are discussed. Among them, the performance of the reversible waveband approach is discussed in detail.Index Terms-Lightpath, reversible waveband, reversible wavelength channel, wavelength-routed networks.

Modelling and Simulation Analysis of Routing Algorithms in Multichannel Optical Communication Networks

“…One of the main tasks is to determine the path from the start node to the end node, which is with the shortest length, using a certain algorithm and a given wavelength which is the responsibility of the medium access control protocols [3,7].…”

“…The physical device and the state of the network determine the range to which the wavelengths can be converted (in whole or in part). [2,3,7] In this paper, a channel-switching model, where a transmission path is set for the entire duration of a session, will be considered as an example. The set of connections through the intermediate nodes from start to end point determines the transmission path with the wavelength specified for each connection.…”