A Sorted-Frame MTP Scheme for Alleviating the Over-Granting Problem in LR-PON

Abstract

Introduction to long reach passive optical network (LR-PON) brings about historic changes in the optical access network. But, one of the many limitations in LR-PON is the grant of excess bandwidth to the optical network units (ONUs) that they don’t even need which is globally known as “Over-granting” problem. The traditional multi-thread polling (MTP) algorithm is unaware of the fact that, the lack of frame fragmentation is prone to the over-granting problem which eventually leads to degradation in the overall delay incurred to the system. Existing enhanced-IPACT (E-IPACT) scheme claims to solve the problem but has some inefficiency. In this very paper, we come up with a new online-based MTP scheme named sorted frame multi thread polling (SF-MTP) where we propose an arrangement of all the frames in order to improve the quality of services (QoSs). Also, wehave presented an effective solution to the reporting of the unreported frames from the previous dynamic bandwidth allocation process. In SF-MTP, ONUs’ are considered to have ability to take necessary decisions. After evaluating the performance by simulations, it implies that the SF-MTP scheme is more economical than other parallel schemes with respect to some QoS parameters.