Study On Hybrid TDM/WDM PON Bandwi-dth Alocation Algorithm In Distribution Co-mmunication Network

Distribution communication network is an important part of the smart grid communication system which takes a hierarchical network architecture including the main station layer, the backbone layer and access layer. In the face of tree chain topological structure of distribution network, power distribution terminal distributed a wide and huge range, various of business needs to be transmitted has a significantly different quality of service requirements’characteristics, passive optical network (PON) has become the main technology in the access layer, and has been large scale deployment in power distribution automation construction. However, the traditional PON access uplink using TDM transmission mode which limited the growth of bandwidth and coverage range has been unable to meet the development of communication network and distribution requirements, while using hybrid TDM/WDM technology’s next generation PON gradually become a hot spot of research due to the advantages of the bigger bandwidth capacity, longer transmission distance and higher reliability.This paper first introduces the distribution communication network architecture, and comparative analyzed the traditional PON system and the next generation of PON system in development history and technical characteristics, focus on the analysis of the technical route and characteristics of network in access layer based on hybrid TDM/WDM PON; Then, we propose an access layer structure of hybrid TDM/WDM PON, and use the discrete event simulation toolbox of SimEvents and finite state machine Stateflow in MATLAB to modeling, designing a OLT module, a link delay module, and a ONU module to building for a special simulation platform. Finally, we study on the bandwidth allocation problem in PON system, proposes a joint slot wavelength and bandwidth allocation for hybrid TDM/WDM PON (JTSW1) algorithm, dynamic allocation is uplink bandwidth by considered the time slot wavelength and queue priority at the same time, and carries on the simulation experiment for the improved algorithm, shows the superiority of the improved algorithm in the mean cycle time and delay, improve the transmission performance of the whole system more than20%.