Methods and Components for Optical Contention Resolution in High Speed Networks

摘要

This project dealt with designing all-optical packet switched networks. To avoid the electronic bottleneck in LAN and MAN topologies this project develops and demonstrates a novel optoelectronic receiver front end consisting of optical delay lines and fast optical switches. The proposed approach combines the advantages of optics and electronics in a Switched-Delay- Line Contention-Resolution-Optics (SDL-CRO) to optically store and switch packets. The resulting SDL-CRO functionally is that of a space and time optical switch which allows packets contending for a common resource to be redistributed over time and space. This provides a unique mechanism for dealing optically with the key problem of contentions that has, so far, only been dealt with in switching systems electronically. By allowing the data to be retained in the optical domain, the O/E and E/O data conversion of conventional fiber-based networks is not necessary. This in turn makes it possible to use WDM techniques to multiplex several high speed data streams onto the optical fiber, without requiring prohibitive parallel signal processing to realize the electronic buffering at intermediate nodes. As a result, the throughput potential of the network may be increased by orders of magnitude. Another advantage is the CRO's node localized principle of operation which makes it usable in a variety of architectures and network topologies. The CROs only require locally available information at the node, i.e., the set of packets in the switch, their respective destinations, and their current slot in the switch. Local resolution of the contention problem avoids critical booking of the other nodes' activities as is required by distributed algorithms. In short, the SDL/CRO offers the significant advantage of contention resolution in an all optical format and could become a key component for an ultra fast, multi-gigabyte, all optical network.