EPONs use a point-to-multipoint topology, in which multiple optical network units (ONUs) share one uplink channel to transmit multimedia traffic to a control element, the optical line terminal (OLT). Hence, to avoid data collision on the shared uplink, ensure a contention-free transmission and so on, medium access control arbitration mechanisms are essential for the successful implementation of EPONs. In this paper, a novel dynamic bandwidth allocation algorithm,
the Integrated Two Classes Dynamic Bandwidth Allocation (ITCDBA), is put forward, in which the multipoint control protocol is used defined in the IEEE802.3ah standard. ITCDBA is a hierarchical allocation scheme which dynamically allocates bandwidth according to the instantaneous demands of ONUs, supporting inter-ONU priority scheduling as well as intra-ONU priority scheduling. The simulation result shows that the system throughput of EPON is improved with
ITCDBA scheme and the drop rate of the traffic with the highest priority is lower than that with Two-layer bandwidth allocation (TLBA) scheme . In a word, ITCDBA not only can allocate bandwidths between end users effectively and fairly, but also can support differentiated services. Besides, the system performance of EPONs with ITCDBA scheme is improved.