ONU migration using network coding technique in Virtual Multi-OLT PON Architecture

Rapid bandwidth expansion necessitates large-scale, high-density access situations, in which a clustered deployment of numerous passive optical network (PON) systems may be used to meet the massive bandwidth needs, particularly for a future 5G mobile network. Multiple optical line terminals (OLTs) based PON is a promising candidate to meet these future demands. However, some of the available bandwidth is wasted because of the absence of collaboration among various OLTs. By applying the concept of network coding methods into OLTs and ONUs, this paper proposes an efficient virtual multi-OLT PON (VM-PON) network architecture for the metro access scenario to improve bandwidth efficiency. This is achieved by using a network coding method that simultaneously transfers two heavily loaded ONUs between the OLTs. By implementing an efficient ONU transfer algorithm, load balancing is also managed in VM-PON among all the OLTs. To improve the network performance and reduce latency, optical network units (ONUs) in the VM-PON may dynamically regroup with various OLTs. The comparative simulation results demonstrate that the proposed VM-PON work achieved 37% throughput greater than traditional TDM-PON with a lower frame loss ratio and lower upstream delay and jitter.