Segment frame replication and elimination for redundant routing provision in the FlexE-over-WDM networks

Flexible Ethernet (FlexE)-over-WDM is one of the promising technologies of 5G transport networks that aims to provide a variety of Ethernet MAC rates over large capacity wavelength channels. Ultra-reliable communication is a key scenario of 5G, which poses a big challenge to the transport networks. To achieve ultra-reliability, frame replication and elimination for reliability (FRER) was proposed by IEEE. 802.1CB to provide redundant transmission in layer 2. However, previous studies of FRER considered to replicate MAC frames at source node and eliminate them at the destination, which may cause a waste of network resources, especially for the services that require different reliabilities in a condition of network with different packet loss rates of link and node. To this end, we propose a novel redundant routing scheme, called segment FRER (S-FRER), to balance the reliability and network efficiency. And a FlexE group allocation scheme is coming with S-FRER to assign the Flexible Ethernet channels along the path. Two heuristic algorithms, which are end-to-end FRER (E-FRER) and ordinal FRER (O-FRER), are compared with S-FRER. Simulation results show that S-FRER can satisfy diverse reliability requirements of services, and the resource redundancy and equipment cost are condensed.We further take the resource utilization efficiency as the optimization goal, and propose a FlexE Group allocation strategy based on segmented frame repetition and elimination to realize the resource redistribution of service flows on redundant routes. The experimental results verify the effectiveness of the scheme in terms of resource utilization efficiency.