Bandwidth-variable optical transport network with adjustable time-modulated and inverse-multiplexed wavelength channels

Abstract

This paper presents a bandwidth-variable and optical-groomable (BVOG) transport network architecture based on time-modulated optical cross-connects that enables efficient switching of periodic burst-sequenced traffic in addition to wavelength streaming traffic; with an elastic control plane that shapes each sub-wavelength traffic stream at the network edge into a sequence of periodic bursts, and inverse-multiplexes a supra-wavelength traffic stream into a group of multiple wavelength traffic streams and a potential sub-wavelength traffic stream to match the bandwidth requirement. BVOG network enables variable-time-slotted lightpaths with variable-length time slots to meet the bandwidth requirements of sub-wavelength traffic; and inversemultiplexed lightpath-group (IM-lightpath-group) with variable group size to meet the bandwidth requirements of suprawavelength traffic. For the problem of "routing and wavelength and time assignment" (RWTA) for sub-wavelength traffic; this paper presents an optimal integer linear programming (ILP) formulation that maximizes total network throughput, and a heuristic algorithm to minimize the blocking probability of future connection requests. For the problem of "inverse-multiplexed routing and wavelength assignment" (IMRWA) for supra-wavelength traffic; this paper presents an optimal ILP formulation that minimizes the total number of hops and the total per-hop propagation delays of the IMlightpath-group, and a heuristic algorithm that minimizes the total number of wavelength channels of the IM-lightpathgroup. The RWTA ILP is solved by the ILOG CPLEX optimization tool, and it is used to check the optimality of the RWTA heuristic. Performance tuning of the IMRWA