Media Access Control Protocal Research On OFDM-PON

Passive optical network has been widely focused on by researchers and industry field because of its high bandwidth and supporting more kinds of communication services. A novel passive optical network (PON) named OFDM-PON which combined orthogonal frequency division multiplexing access (OFDMA) with passive optical network is proposed and widely discussed in all fields.At first, the thesis introduces the key technologies in OFDM-PON, especially these in MAC layer. Then the thesis researched the media access control mechanisms in passive optical network and analyzed existing dynamic bandwidth allocation algorithms. A novel DBA algorithms is proposed in the thesis, which not only supports multi-service access but also ensure QoS distinguishing user level at special case. The proposed algorithm uses two-level mechanisms during the allocating progress. In intra-priority allocation, the DBA algorithms applied bandwidth pre-allocation mechanism to ensure the quality of EF service and the applying of proportional allocation mechanism plays an excellent balance between the priority of different services and fairness between the higher and lower priority service. During the allocation of inter-priority, the principle of smallest bandwidth request allocated first combined with proportional allocation mechanism is used between ONU among the same priority. The simulation results show that, compared with traditional DBA algorithms, the proposed algorithm guarantees the QoS requirements of different type of services excellently.