• Summary
• Related Documents
  • Active Bibliography
  • Co-citation
• Version History

Abstract:

The multihop approach to lightwave networks makes it possible to create networks that offer hundreds of thousands of gigabits-per-second total capacity, shared among many users, with each user limited to a peak rate that can be supported by electronic interfaces. The optical passive star has emerged as the physical medium of choice for supporting various virtual topologies. The Shuffle-net is a well known virtual topology, involving wrapped around connections between the last and first stages of the network, that can be supported on an optical passive star. In this paper, we introduce the idea of providing reverse channels in such networks with minimal hardware costs, to reduce the network diameter, improve average delay and provide other advantages. The reverse channel idea can be applied to any multistage network with wrapped around connections, e.g., the MIN or the Butterfly networks. We demonstrate the advantages of reverse channels by providing a simple reverse connection between adjacent stages of the Shuffle-net. Time and Wavelength Division Multiplexing (TWDM) is then used to provide the media access protocol for the nodes in the network. The benefits of using reverse channels in Shuffle-net are shown via simulation and bounds on network performance metrics are derived analytically. We show how a TWDM protocol for the Shuffle-net can be easily adapted for the Reverse Channel Augmented Shuffle-net (RC-Shuffle-net). The addition of a reverse channel is shown to be beneficial in a large network with significant propagation delays, such as a MAN. We highlight several issues for further research using this idea.

Citations