Capacity enhancement of local area bus networks using wavelength division multiplexing
This article investigates the possibility of using wavelength division multiplexing to enhance the system capacity of local area networks with the bus topology, and which employ some type of distributed or centralized reservation. We first consider the choice between wavelength fixed and wavelength tunable transceivers based on practical considerations, and we conclude that the use of fixed wavelength transceivers allows one to employ WDM while still using standard interface cards. This requires that wavelength translation be implemented in the network. The article then considers the problem of wavelength translation and introduces three approaches: the min-max approach that minimizes the maximum load on channels; the Translation at Destination approach where the wavelength translation is carried out only at the ingress point to the receiving channel, and the Translation at Source approach in which the wavelength translation is carried out at the egress point from the source. Practical algorithms for implementing these optimal allocations are considered. We consider heterogeneous systems within the scope of two problems: the load distribution on different channels, and the system capacity. A linear programming approach is introduced in order to assess the capacity enhancement in the general heterogeneous case. In the homogeneous case, closed form expressions can be obtained. Finally, we present simulation results based on these algorithms for a DQDB network in order to assess the degree of performance enhancement. (C) 1999 Elsevier Science B.V. All rights reserved.
capacity wavelength division multiplexing optimization linear programming simulation dqdb performance dual bus lans crma erasure node