An efficient wavelength reusing/migrating/sharing protocol for dual bus lightwave networks

High-speed lightwave networks employing linear fiber bus topology have become attractive with the emergency of erbium-doped optical amplifiers. Moreover, the huge network capacity in a dual bus lightwave network is obtained by several parallely transmitting channels (wavelengths) on each bus. By applying the wavelength reusing concept, nonoverlapping traffic in the network can be serviced simultaneously to achieve high network throughput. It is also possible that a new incoming request is blocked even the bandwidth between the source and the destination is available. Nevertheless, this request may be accommodated by migrating some existing connections. Due to the number of wavelengths is limited, some requests may further share the same wavelength to improve the network throughput. In this paper, an efficient distributed wavelength reusing/migrating/sharing protocol (WRMSP) for the dual bus lightwave networks (DBLN) is proposed. This protocol consists of three efficient schemes for carrying out the wavelength reusing, migration and sharing, respectively. Simulation results show that for a limited number of wavelengths and tunable receivers, the proposed protocol substantially improve the network throughput and access delay under general traffic demands.