An efficient intra thread scheduling based decentralized online multi thread polling scheme for improving QoSs of PON

One of the major challenges in long reach passive optical network (LR-PON) is the longer end-to-end traffic delay between the central office (CO) and the end user. This longer delay significantly hampers the quality of services (QoSs) of the optical access networks. The QoSs of the LR-PON are easily affected by delaying or dropping packets as a consequence of parameters such as latency, jitter, bandwidth utilization and packet loss. Most of the studies have only focused on capacity allocation amongst the multiple optical network units (ONUs) of the network by the optical line terminal. Some research also proposed to schedule the packets in multiple threads based on the priority. However, due to the lacking of intra thread scheduling scheme the high priority (HP) data packet still suffering from more delay. In this paper, we propose a decentralized intrathread scheduling scheme that provides lower queuing delay as well as end-to-end packet delay of the HP traffic. The performance measurements involve several scenarios which combine different traffic types, intra ONU scheduling and queuing policies. The goal of this research is to identify the most suitable scenario to provide qualitative services and efficient resource utilization among different traffic types. The performances of the proposed scheme have been analyzed and compared with the existing scheme by numerical simulations. The numerical results proves the advantages of the proposed scheme over the existing one in terms of lower average packet delay of high priority data packets and higher network throughput under varying offered loads.