Mechanisms for providing optical bypass in WDM - based networks

The recent emergence of Wavelength Division Multiplexing (WDM) technology has led to a tremendous increase in the available transmission capacity in wide-area netwo r k s. Consequently, these networks may no longer be limited by transmission bandwidth, but rather by the processing capability of electronic switches, routers and multiplexers in the network.This realization has led to a new wave of research aimed at overcoming the electronic bottleneck by providing optical bypass at the WDM layer. In this paper we survey some of the recent work in this area, including mechanisms for providing optical bypass in both circuit and packet switched netwo r k s.We pay part i c u l a r attention to techniques that take advantage of configurable WDM technology to dynamically reconfigure the electronic topology of the network in response to changes in traffic c o n d i t i o n s. We show that for both circuit and packet switched traffic, having a configurable WDM topology can lead to a significant increase in network capacity. Figure 1: Using a WADM to provide optical bypass. © 2000 SPIE/Baltzer Science Publishers 1388 6916/2000 $15.00 Docu-Modiano/Narula 24-11-1999 23:05 Pagina 9