Wavelength-Routed Networks With Lightpath Data Interchanges

Abstract

Abstract-We observe that tunable wavelength converters (TWCs) that are traditionally installed in wavelength-routed (WR) networks for wavelength contention resolution can be further utilized to provide fast data switching between lightpaths. This allows us to route a data unit through a sequence of lightpaths from source to destination if a direct single lightpath connection is not available or if we want to minimize the overhead of setting up new lightpaths. Since TWCs have a tuning time of picoseconds, it may be possible to use the installed TWCs as lightpath data interchanges (LPIs) to improve the performance of WR networks without significant optical hardware upgrade. Compared with the multihop electronic grooming approach of lightpath networks, the LPI approach has a simpler WR node architecture, does not need expensive high-speed electrical multiplexersÕrouters, and does not sacrifice the bitrateÕformat transparency of data between the source and destination. Our simulation results show that WR networks with LPIs can have much lower blocking probability than WR networks without LPIs if the traffic duration is short. We show that LPIs can also be used to provide new data transportation services such as optical time division multiplexing access (OT-DMA) time-slotted service in WR networks.

Application of lightpath data interchange in optical burst-switched networks

“…Recently, we have investigated using lightpath data inter change (LPI) to support fast data switching and more effective bandwidth utilization in wavelength routed (WR) networks [2]. LPI method is found to be useful for solving the large TSIV problem of OBS.…”

“…Since the data burst transmission time can be much smaller than the propagation delay between nodes, an OBS node will not be easy to have the detailed status of downstream nodes. Hence, the original approach of LPI [2] that relies on the cooperation between transmissions from different nodes will no longer be viable. In contrast, the external LPI in Fig.…”