SDN East–West cooperation in a converged fixed-mobile optical access network: enabling 5G slicing capabilities

Abstract

The new 5G service requirements will force operators to rethink the deployment of infrastructure and management tools. The reuse of passive optical network (PON) technology to connect antenna sites has attracted the attention of some operators, as the high availability of some 5G services, as well as ubiquitous radio coverage in a denser network, could be ensured with minimum deployment efforts. In this case, the implications of each 5G slice instance deserve to be clarified in a PON infrastructure, and a fixed-mobile converged management system in optical access networks (ANs) will be necessary for operators. Some class of service (CoS) algorithms must be developed to ensure that different and heterogeneous services are properly transported through optical fibers in a fixed-mobile converged scenario. Many organizations are considering the use of transmission containers (T-CONTs) (the indicator of the bandwidth distribution in the PON uplink) for PON slicing, but the CoS for mobile traffic in a PON has not yet been defined. In parallel, the new AN management solutions are mostly focused on software-defined network (SDN) northbound/southbound interfaces between orchestrators and abstraction entities. However, if an end-to-end 5G slice instance must be dynamically applied in a fixed-mobile converged architecture, the coordination between mobile and residential management systems is necessary. We propose a disaggregated optical line terminal (OLT) with an SDN controller that leverages the advantages of virtualization technologies and the currently deployed OLT. We propose an East–West interface between fixed and mobile SDN controllers and have successfully implemented a 5G slicing proof of concept in access transport networks using this interface. We succeeded in reducing uplink latency and jitter by 25%–50% thanks to a smart optimization of T-CONTs, which could be interesting for ultrareliable and low-latency communications applications. A discussion of T-CONTs for slicing is also given based on experimental measurements.