Partially Online Dynamic Bandwidth Allocation Algorithm for Hybrid TDM/WDM EPON

Abstract

Dynamic Bandwidth Allocation (DBA) is a fundamental task in Ethernet Passive Optical Networks (EPONs). An EPON must use an efficient DBA to achieve good network performance. A variety of DBA algorithms have been proposed towards this end. Most of these algorithms use average packet delay as an important metric for measuring the performance of the algorithm. In this paper, algorithms for Time Division Multiplexed (TDM) EPON and Hybrid TDM/WDM (wavelength division multiplexed) EPON are briefly reviewed. A Partially Online DBA (ParOnD) for Hybrid TDM/WDM EPON is proposed to improve bandwidth utilization in Hybrid EPONs. After evaluation of ParOnD against a comparable algorithm for Dynamic Wavelength and Bandwidth Allocation (DWBA- 2), it is analyzed that ParOnD reduces both packet delay and the average queue depth of an Optical Network Unit (ONU) over low to medium loads. Thus, ParOnD improves bandwidth utilization considerably. In the paper, analysis of the algorithm, its shortcomings and possible future improvements are discussed.