J.S. Sohal

Wavelength Converter Using Semiconductor Optical Amplifier Mach-Zehnder Interferometer Based on XPM at 40 Gb/s for Future Transport Networks

Abstract We have simulated, for the first time, wavelength converter for future broadcast networks at 40 Gb/s using low-cost semiconductor optical amplifiers. The performance analysis is carried out for an all-optical frequency converter based on cross-phase modulation in two semiconductor optical amplifiers arranged in a Mach-Zehnder interferometer configuration to evaluate the efficiency of conversion. The results, evaluated analytically for input, return to zero signal at a bit rate of 40 Gb/s show that conversion is possible over a wavelength separation of 1 nm between the pump and the input wavelength. Increasing the driving current can decrease the cross-phase modulation effect. The cross gain modulation scheme shows extinction ratio degradation for conversion to longer wavelengths.

A Novel Shared Protection Scheme Based on Aggregate Wavelength in High Speed Networks

We propose novel analytical model of dynamic link cost evaluation in IP over WDM networks. We suggest disjoint path algorithm for the primary and backup path based on wavelength aggregate information, to provide shared backup. We show the optimality of pair selected because of joint optimization of the pair paths. The shareable capacity factor is introduced to establish the effect of load balancing on resources. We compared our simulation results with that of separate protection at connection and showed improvement on resource utilization performance of the network. We also study the blocking probability of proposed scheme.

An Efficient Network Utilization Scheme for Optical Burst Switched Networks

Optical Burst Switching OBS is one of the most important switching technologies for future IP over wavelength division multiplexing WDM networks. In OBS Network, the burst assembly technique is a challenging issue in the implementation of the system. Burst assembly influences burst characteristics, which negatively impacts network performance. In this paper, the authors propose an efficient hybrid burst assembly approach, which is based on approximate queuing network model. To reduce the time complexity, an approximate queuing network model has been considered. Throughput performance has been investigated, taking into account both burst loss probability and time complexity. Simulation results have shown that the proposed hybrid approach based on variable burst length threshold and fixed maximum time limitation provides Simulation results have also shown a good trade-off between burst blocking performance and scheduling time.

Combined Path and Maximum Empty Static Routing Algorithms with Wavelength Assignment for Future Transport Networks

Abstract In this article, two static routing algorithms have been proposed and compared to some of the existing algorithms on the basis of blocking probability. The two proposed static routing and wavelength assignment algorithms reduce the blocking probability to maximize the utilization of the network. All of these algorithms are analyzed and compared with four wavelength assignment schemes, which are first-fit, random, most used, and least used. It is shown that our proposed static algorithms give the best performance for first-fit wavelength assignment and most used wavelength assignment strategies with reduced complexity. For least used wavelength assignment and random wavelength assignment, 1 fixed and 2 alternate routing algorithm gives the lowest blocking probability.