To improve the optical access network capacity, it is urgent to smoothly upgrade the existing access networks to the next generation optical access network:Time and Wavelength Division Multiplexing-Passive Optical Networks (TWDM-PON). TWDM-PON increases the access rate by stacking multiple Time Division Multiplexing-Passive Optical Networks (TDM-PON) in manner of Wavelength Division Multiplexing (WDM). TWDM-PON is a promising network for surpassing both TDM-PON and WDM-PON, which combines the advantages of these two technologies and avoids their weaknesses. As TWDM-PON has a point-to-multiple-points topology, the upstream bandwidth allocation scheme plays a vital role in ensuring the network performance.This thesis has studied the upstream bandwidth allocation schemes of TDM-PON and WDM-PON, on basis of which we proposed a dynamic wavelength and bandwidth allocation (DWBA) scheme named large request first-fair excess allocation scheme (LRF-FE) to manage the resources in TWDM-PON. LRF-FEAS is an integral resource management scheme and LRF-FE algorithm is the core, which exploits both inter-channel and intra-channel statistical multiplexing. LRF-FE effectively reduces unused time slots in channels, therefore network average delay drops and utilization of the expensive wavelengths improves. On the other hand, LRF-FE fairly allocates the bandwidth among optical network units (ONUs).Simulation results show that compared with two existing schemes in TDM/WDM EPON, the average packet delay of networks is reduced at most46.19%and18.45%, the resource utilization is also higher by an amount at most 31.6%and15.6%and the service offered to different users is much fairer. In conclusion, LRF-FEAS is an effective and fair resource scheme applied in TWDM-PON. |