Proposed filterless architecture and control plane for emerging flexible coherent networks

Recent developments in coherent modem performance and digital signal processing (DSP) technologies have opened the opportunity for new agile network architectures [1, 2]. The filterless network concept has been proposed in [3] and it is shown that they are more cost-effective and reliable compared to active optical switching networks. Filterless optical networks use broadcast-and-select techniques in which passive non-filtered optical splitters and combiners are used for channel add-drop and fiber link interconnection. Furthermore, DSP-based coherent modems are complementary foundational technologies for flexible optical networking owing to their properties of dynamic impairment compensation, performance monitoring and tuneability. The resulting network architecture makes an attractive candidate solution for flexible optical networking [4]. In this talk, we review the recent progress in filterless optical network design and control [5]–[7]. In the first part, filterless architectural solutions are proposed for different network topologies and compared to active photonic switching solutions. A cost and performance analysis of filterless network solutions with 1 + 1 optical layer protection is also presented. In the second part, we present a control plane for filterless optical networks and describe its main characteristics through a performance study. Our results show that passive filterless networks can be considered as a cost effective and simpler alternative to active optical switching networks whenever traffic loading is not approaching full network capacity.