A Distributed Control Plane Architecture for Epon: Simulation Study and Feasibility Experiment

Ethernet Passive Optical Network (EPON), an access network technology, has drawn considerable research attention in recent years. EPON can be implemented in centralized or decentralized architecture in the access network. Most of the researches were focused on the centralized architecture, where bandwidth allocation decisions for Optical Network Units (ONUs) are made by distant Optical Line Terminal (OLT). In centralized approach, ONU reports have to travel to distant OLT to inform the OLT about their bandwidth needs so ONUs may be granted upstream bandwidth. Any software failure in the OLT will halt the ONU upstream transmission. In this paper we introduce two works: a simulation study of a distributed Dynamic Bandwidth Allocation (DBA) scheme over a decentralized architecture and an experimental study to explore the control plane feasibility of such an architecture. Firstly, we observe the performance of the decentralized DBA scheme associated with the Ethernet over Star Coupler-based Passive Optical Network (PON) architecture, where OLT is excluded from the implementation of the upstream time slot assignment. To implement this distributed control plane, the architecture facilitates inter-ONU connectivity to exchange control information among ONUs. Secondly, we conduct a physical layer experiment to assess the feasibility of implementing such a control plane architecture. In addition to the added flexibility and reliability of a distributed architecture, the proposed DBA performance over the distributed EPON is shown to be more efficient than its centralized counterparts. Furthermore, the control plane of such an architecture is also proven to be feasible by physical layer experiment.