Spatial Group Sharing for SDM Optical Networks with Joint Switching

Abstract: Space Division Multiplexing (SDM) is a promising approach to overcome the looming fiber capacity crunch. Joint and Fractional Joint Switching architectures, which switch multiple spatial dimensions together as atomic units, have been proposed to reduce the cost of implementing SDM and cater to strongly coupled transmission media. However, they have been shown to impose significant penalties to overall network performance, at least when many relatively small connections are used in the context of uncoupled spatial dimensions. With respect to this latter type of SDM networks, in this work we tackle the performance penalty that Joint and Fractional Joint Switching architectures impose on such a system compared to the Independent Switching Architecture, by proposing two novel Routing, Space and Spectrum Allocation heuristics that effectively share jointly-switched resources, adapted to use different types of SDM Reconfigurable Optical Add/Drop Multiplexer (ROADM) architectures requiring only a small additional cost. We find that our proposals can achieve significant improvements in the performance of SDM networks carrying large number of relatively small connections, up to parity of performance with Independent Switching designs, at a lower implementation cost.