High utilization dynamic bandwidth allocation algorithm based on sorting report messages with additive-polling thresholds in EPONs

Abstract

High utilization is one of the design goals for MPCP-based dynamic bandwidth allocation (DBA) algorithms in Ethernet passive optical networks (EPON). However, utilization is sacrificed in order to meet the delay limits of the applications in most DBA design schemes. This paper proposes a dynamic bandwidth allocation algorithm based on sorting report messages with additive-polling thresholds (AP-Sort DBA). This has the characteristics of high utilization and low delay during medium network loading. AP-Sort DBA is an extension of the adaptive dynamic bandwidth allocation algorithm with sorting report messages (Sort-DBA) and promotes utilization by reduction of unused slot remainders (USR) and distribution of excess bandwidth. For performance evaluation in terms of average delay, average queue size, loss rate and utilization, five DBA schemes are simulated, namely AP-Sort DBA, interleaved polling with adaptive cycle time (IPACT), dynamic bandwidth allocation with a modified grant table generation algorithm and fair-excess allocation (DBA2-FE), Sort-DBA and double phase polling algorithm (DPA). Self-similar traffic and OC-3 packet size distribution are used for frame generation. The results show that AP-Sort DBA can achieve up to 99% utilization, which is the highest among the tested alternatives, with up to 60% improved delay compared to the IPACT. Technical analysis is presented for further proof of the effectiveness of the proposed methodology.