Predictive Credit Based Dynamic Bandwidth Allocation Mechanisms in Ethernet Passive Optical Network

Ethernet passive optical networks (EPON) is being considered as promising solution for next-generation broadband access network. EPON has the features of low-cost Ethernet deployment and highspeed optical connections. The mission of IEEE 802.ah Task Force is to construct a solid structure for deployment where it defines the multi point control protocol (MPCP) and leaves details of dynamic bandwidth allocation (DBA) for vendors and researchers. ONU and OLT exchange REPORT and GATE messages to coordinate the transmission time and bandwidth allocation fro upstream traffic. Quality of service (QoS) is one of the main features required in EPON. Delay-sensitive applications, such as VoIP, video streaming, should be taken care. In this paper, we will investigate the ideas of predictive credit mechanism in EPON. If a suitable credit is assigned, some packets won´t have to wait another cycle time to get transmitted. We have found that the packet delay can be shorter by sacrificing a little bandwidth in some scenarios. We have shown and proposed several predictive credit mechanisms and compared them to the mechanism without prediction