| With the fast development of communication technology, the requests for bandwidth of users are increasing. EPON (Ethernet Passive Optical Network) technology represents the convergence of mature Ethernet technology with PON and is regarded as the best candidate technology of next generation access network because of its low-cost, broad bandwidth, simple maintenance, excellent performance-to-cost ratio and providing multi-service.Since EPON is a multipoint-to-point system, a major feature for this new architecture is the use of a shared transmission media between all users; hence, medium access control arbitration mechanisms are essential for the successful implementation of EPON: ensure a contention-free transmission and provide end users with an equal access to the shared media. In this article, we give a detailed presentation of MAC defined within the IEEE 802.3ah Task Force, including multipoint control protocol (MPCP), Operation Administration Maintenance (OAM) and dynamic bandwidth allocation (DBA) algorithms.To effectively and fairly allocate bandwidths between end users and ensure Quality of Service (QoS) requirement, we propose a new fixed cycle polling dynamic bandwidth allocation algorithm. This proposed algorithm consists of two parts: one is scheduling between OLT and ONU, and the other is scheduling between priority queues in ONU. It is showed by simulation results that the algorithm ensures the QoS of different services with higher priority and can improve bandwidth utilization, meet the requirement of EPON system.At the end of this article, we propose the design and implementation of software for EPON according to the EPON special chips, give a detailed presentation of how to configure our algorithm on EPON chips with API functions. |
