OPEN PON: Seamless integration between 5G core and optical access networks

Abstract

Nowadays business and users traffic demands are getting higher and higher, leaving optical fiber as the only reliable solution to meet its demands, and in access networks the dominating technology is Passive Optical Networks (PONs) where currently exists two main families of standards, the GPON (ITU-T standard) and the EPON (IEEE standard). In this work we tackle the latest version oof the GPON family, the NG-PON2. We analyse the Physical Media Dependent (PMD) and Transmission Convergence (TC) layer requirements and what is standardized in each one. We also have a look into the SDN paradigm, which decouples the control and data plane of network equipment concentrating the intellegence and complexity in a centralized controller, the OpenFlow protocol that is one of the main enablers of SDN, since it is the communication protocol betwwen the network devices and the SDN controller, and the SIEPON (IEEE 1904.1) standard which gives interoperability of the transport, service, and control planes in a multi-vendor environment. The introduction of the SDN paradigm in the xPON world is a hot research topic because it would add the total controllability of the PON infrastructure, and the coordination with the SDN-based control plane of the core networks. It would allow a centralized optimization of the different resources managed by the OLTs and a seamless coordination between OLTs and the core network. In the TC layer specifications, of NG-PON2, it is not standardized the bandwidth allocation of the system, we set ourselves to create a simple Dynamic Bandwidth Allocation (DBA) algorithm that would optimize the use of channels and wavelengths. Taking into account the NG-PON2 technology and all its features, the emerging trend to extend SDN to the optical access networks, the multi-vendor adaptation provided by the SIEPON stantdard, and the need to have a platform to develop and test DBA scheduling algorithms made that thecreation and deployment of a fully SIEPON-SDN-NG-PON2 emulation environment became the main goal of this work. To create this environment we employed the use of MikroTiks, where OpenWRT was installed as well as a set of packages that menabled the behaviour of a CPqD switch (or ofsoftswitch13), and the use of Raspberry Pis which maintained its original OS and only required the installation of a sepecific set of tools. The results obtained were quite positive confirming the possibility of not only creating but also testing different DBA scheduling algorithms in the deployed environment and matching the results expected to our created algorithm.