The Reseach Of Multi-Wavelength And Multi-Frequency Bandwidth Allocation Algorithms That Combines The Twdm-PON And OFDM-PON

With the user’s growing demand for network bandwidth, optical access network has stepped into the era of rapid development. For the increasing proportion of data services and the diversification of business types, the existing access network has been unable to afford the data transmission of such a huge task. So more and more people are paying close attention to the research of next generation access network. In order to meet the various business requirements required to run the network, next generation access network should be able to meet these features, such as high transmission rate, long transmission distance, as well as the small allocation granularity. Because of low bandwidth utilization, large allocation granularity, and the dependence on the high speed passive optical components of TWDM-PON, we need a more efficient scheme of access network. While to OFDM, it just can overcome the above shortcomings of TWDM-PON, WDM-OFDM-PON is the combination of the above two access network. WDM-OFDM-PON has the advantage of both TWDM-PON and OFDM-PON, especially the flexible allocation granularity, It has been verified by some experiments that an OFDM subcarrier is a minimum allocation unit, arbitrary OFDM subcarriers of different wavelengths can be assigned to an ONU, obviously, this is what is much needed in today’s access networks, so WDM-OFDM-PON was recognized by the industry as one of the alternative technology for the next generation access network. As the WDM-OFDM-PON is the new access network that is the integration of TDM,WDM,OFDM technology, so the special bandwidth allocation algorithm which can fully exert its flexibility on wavelength, frequency, time is needed to design for WDM-OFDM-PON, the proposed three-dimensional dynamic allocation algorithm with wavelength, frequency, time should just meet this.By combining the national863plan project, national natural science funds, access network experiment platform based on laboratory and OPNET simulation platform, the author studies further about the WDM-OFDM-PON resource allocation problem, the content of research and main innovation points of the paper is showed in the following aspects:1). This paper analyses the advantages and disadvantages of TWDM-PON and OFDM-PON, expounds the working principle and technical characteristics of WDM-OFDM-PON, and gives the physical implementation scheme of WDM-OFDM-PON based on optical frequency comb (OFC).2). A simulation platform of WDM-OFDM-PON is built by the OPNET to achieve the key features of WDM-OFDM-PON such as wavelength division multiplexing, frequency division multiplexing and time division multiplexing, and complete the debugging and functional verification. The performance of the algorithm proposed in this paper is evaluated by this simulation platform.3). A three-dimensional dynamic allocation algorithm combines the wavelength assignment algorithm based on TWDM-PON and subcarrier allocation algorithm based on OFDM-PON is put forward, It has the characteristics of parallel processing, in proportion allocation, allocation by priority etc. The simulation results show that the algorithm has realized the three dimensions of bandwidth resources optimization and coordination, access bandwidth and network capacity are increased obviously.