The wavelength-division-multiplexing (WDM) network architectures, in general, are based on transmitters and/or receivers that can be precisely, and speedily, tuned to predetermined, fixed wavelengths. These requirements are not easy to meet in practice. Robust WDM networks do not rely on fixed wavelength channels. Any node that requires a connection with another node dynamically selects a currently unused wavelength in the spectrum. Two medium access control protocols for robust WDM networks are presented and evaluated.

Medium access control protocols for robust wavelength division multiplexed local area networks

The wavelength division multiplexing (WDM) network architectures, in general, are based on transmitters and/or receivers that can be precisely and speedily tuned to predetermined, fixed wavelengths. These requirements are not easy to meet in practice. Robust WDM, the subject of this paper, has been introduced as a technique to implement WDM in the local area. The strength of this novel approach is that it does not rely on wavelength-sensitive devices that are required to perform with extreme stability. This paper describes the basis of this approach and presents two types of medium access control (MAC) protocols that are suitable for Robust WDM local area networks (LANs). The performance of networks based on these protocols is discussed in detail. It is shown that the new approach has considerable promise for WDM networks in the local area.

Robust wavelength division multiplexed local area networks

Robust wavelength division multiplexing (WDM) is a technique to implement WDM local area networks (LAN's) in the presence of laser wavelength drifts. A medium access control (MAC) protocol is used in conjunction with a wavelength-tracking receiver to tolerate the variations of transmission wavelengths. Among the proposed medium access schemes, the aperiodic reservation (AR) scheme with token-passing based control channel gives the best performance. An AR protocol with a lenient token passing policy (AR/LTP) is thus presented. An analytical model is developed to design Robust-WDM AR/LTP LAN's and predict their performance characteristics. The model can be used to evaluate the variation of waiting time and throughput for load and network parameters such as the arrival rate, number of nodes, number of channels and timing parameters. It also addresses the issues related to traffic loss, channel-blocking, token rotation time, network span, and the effect of device parameters.

Modeling and performance analysis of a symmetric fast-circuit switched robust-WDM LAN with the AR/LTP protocol

WDM networks in general depend on transmitters and receivers that are precisely tuned to predetermined fixed wavelengths. Robust WDM is an approach aimed at relaxing manufacturing and operating wavelength tolerance requirements, which will lead to cost effective implementations. In this approach, connections are based on dynamically selected wavelengths as opposed to using fixed wavelength channels. A station that needs a connection selects a wavelength during a reservation interval. The performance of a simplified WDM protocol with dynamic wavelength selection is modeled and analyzed for packet traffic. In this version, the reservation intervals are assigned to stations randomly. The performance of the protocol is analyzed for different network parameters.

/pdf/performance-of-a-packet-switched-wdm-network-with-dynamic-3dp1pbeida.pdf

Performance of a packet switched WDM network with dynamic wavelength selection

The robust-WDM is proposed to realize wavelength division multiplexed (WDM) local area networks (LANs) in the presence of laser wavelength drifts. The approach of robust-WDM is to design access protocols that can exploit a new wavelength-tracking receiver. We introduce an analytical model that can be used as a tool to design robust-WDM LANs, and to predict and understand their performance characteristics. The model is designated for a class of these networks that relies on an aperiodic-reservation based access protocol and uses a token-passing control channel to organize the right to reserve among nodes.

Modeling and analysis of waiting time in a symmetric fast circuit switched robust-WDM LAN with an AR/LTP MAC protocol

An architecture is described which accommodates the difficult physical constraints in a WDM optical network, especially the inevitable wavelength drifts many times the source linewidths, by using an adaptive receiver system. The equally difficult and conflicting requirements of a multi-media, multi-Gb/s network of fixed and low latency, guaranteed bandwidth, and multi-cast have also been met by adapting the DTM protocol to mixed WDM and TDM optical formats.

http://ieeexplore.ieee.org/iel2/4484/12728/00586336.pdf

Temkin

Papers

A robust WDM communication system