Research On Technologies Of The Carrier Reused And Multicast Transmission In WDM-PON

With the rapid development of video on demand, high-definition TV, VoIP and others, future optical networks will require better performance and higher capacity, especially in broadband access networks. However, the traditional xDSL access methods for these services can not meet the demand very well, so the emergence of new technologies is urgent needed. In this way, the passive optical network (PON) has aroused much attention and Time Division Multiplexing Passive Optical Network (TDM-PON) technology has been commercially available. However, the user can only get the limited bandwidth because many users share the bandwidth resources. As the result, the limited bandwidth can not meet future requirement. More over, it is difficult to manage the time slot. Fortunately, Wavelength Division Multiplexing Passive Optical Network (WDM-PON) can address these issues well and WDM-PON has been considered as a promising solution for the next-generation of FTTx. In this thesis, carrier reused and multicast transmission technologies in WDM-PON are main research works. At the beginning, it introduces the basics of access networks and analyzes WDM-PON system, so the significance of this research work is emphasizes. In order to achieve low-cost of ONU in WDM-PON system, the problem of"colorless"should be solved firstly. Uplink carrier re-modulation technique is a promising scheme to solve the problem. Based on the analysis on the existing carrier reused schemes, this thesis investigate on the IM format configuration and gives out the optimal performance point, which I think has direct value to the following research works. With the increasing of number of users'business in the WDM-PON system, multicast/broadcast business is also the main problem needed to solve. Based on the analysis on the existing multicast scheme, a new multicast scheme has been proposed, which is realized by using dynamic switching to choose the NRZ or Manchester formats. Though dynamic switching to select modulation format of downstream data, the multicast/broadcast technology can be realized. The new scheme can be flexible to achieve the multicast / broadcast service and it has many advantages such as simple architecture, and easy to recover clock.To further improve the high-speed data processing capabilities in optical network nodes, this thesis has studied the low voltage differential signaling (LVDS) technology. LVDS uses the very low voltage to transmit high-speed data and can achieve point to point or a multipoint connection. The Key technologies of LVDS including producing clock, sending data and receiving data are realized by verilog. Further, the ModelSim6.2C is used to simulate all single units and the whole system to verify the system functions. It provides a good reference resolved program for the high-speed data processing in the future.