An efficient dynamic bandwidth allocation for GPON long-reach extension systems

Abstract

Long-Reach (LR) extension is a promising scenario for the future next generation access networks, enabling less Central Offices (COs) in the field and a large number of customers in the access/metro area. Because of the large propagation time between OLT and ONUs, inefficiency occurs in the Dynamic Bandwidth Allocation (DBA) upstream protocols. To solve this drawback, a new efficient DBA protocol, named GPON Redundancy Eraser Algorithm for Long-Reach (GREAL), is proposed, removing the redundancy caused by an ONU polling cycle or Scheduling Interval (SI) smaller than the Round-Trip-Time (RTT), while providing also multi-service QoS. This algorithm is independent of the SI and uses real data queuing information without prediction, achieving a great enhancement in bandwidth utilization. Nevertheless, prediction techniques can be used together with the GREAL algorithm, improving the DBA protocol and the bandwidth management.