A study on the hybrid bandwidth allocation algorithm to support multiple services in ethernet PON

Abstract

In this thesis, we suggest the hybrid bandwidth allocation algorithm to support multiple bandwidth allocation algorithms for upstream channel access in Ethernet PON. We can see that the network master provides subscribers`` required differentiated services with different bandwidth allocation schemes in Ethernet PON by applying the proposed hybrid bandwidth allocation algorithm. The proposed scheduling algorithm allows us the simultaneous approach of multiple access control schemes, i.e. SBA (Static Bandwidth Allocation) for the time- sensitive, constant bit rate transmission services and DBA (Dynamic Bandwidth Allocation) for the best-effort services. We separate the process of grant transmission start time decision from the process of grant generation in order to reduce the complexity of the various scheduling modules. This scheduling technique does not require timing related information of other bandwidth allocation modules, and thus respective modules are free from heavy amount of information, complex processing and convergence delay due to the multiplexing between modules. Especially for best-effort services, we design priority-based ONU model to differentiate the real-time video and voice service from other best-effort services. We design the model of the proposed hybrid bandwidth allocation algorithm using the OPNET simulator, and we can obtain the various simulation results according to the respective performance parameters. When we compare the simulation results in respect of throughput and channel utilization, the hybrid bandwidth allocation algorithm shows the similar results to the existing bandwidth allocation schemes at the non-busy network condition, but at the busy network condition, the proposed algorithm shows the lower throughput and utilization than the existing algorithms by about 10%. When we compare the queuing delay results, the proposed hybrid bandwidth allocation algorithm represents about 1 ms in respect of SBA and 0.1ms in respect o...