Passive Optical Network Technology And Bandwidth Allocation Algorithm

Since the seventies of the 20th century when the optical fiber communication system emerged, the fibers have almost covered every coner in all over the world. Recently, the total capacity of per big node is over 5Tb/s in optical transmission network in China. As the backbone network transmission rate has reached a Tbit level, the rate of access network has become a bottleneck in the development of the whole network. With the development of the internet and broadband applications, FTTH (Fiber to the Home) is considered as an excellent integrated solution for access network. The broadband access system is evolving from traditional copper wire access toward to the goals of optical fiber substitution for copper wire, mobility of wireless broadband, fixed and mobile complementing, and fulfillment of seamless access. As optical transmission become more important in the access networks, optical broadband access is an inevitable selection of a fixed network to develop its broadband access.Passive optical network is most suitable for an optical access technology for FTTH, and the passive optical networks through the development of the early APON/BPON, the most widely used of the EPON and GPON. The traditional passive optical network using the time division multiplexing technology, the network of all the ONUs share a single wavelength, in different time slots in the transmission of data services. With wavelength division multiplexing technology in access network applications, WDM-PON is the next step from today’s EPON/GPON to accommodate further traffic growth and facilitate new applications. WDM-PON is a new generation optical access network technology which has the characteristics of large capacity, network security and upgradability. Because for each ONU are using a specific wavelength, so to achieve a point to point connection for each user provides a specific wavelength, has become a representation of future broadband access technologies.In this paper, we launched a system-depth theoretical and experimental study around the multiplexing used in passive optical networks, traditional GPON technology, WDM-PON technology, and WDM-TDM hybrid PON system. The main contributions of this paper are as the followings:(1) The theory and technology used in passive optical networks are analyzed. Discussion on the time division multiplexing, wavelength division multiplexing, frequency division multiplexing, space division multiplexing, statistical multiplexing, and other channel multiplexing are present.(2) The dissertation analysis of the bandwidth allocation for passive optical network, and the characteristics of the current operations and a variety of bandwidth allocation strategies are discussed in detail.(3) The gigabit-class passive optical network (GPON) based on the traditional time-division multiplexing is analyzed. The functional structures of OLT and ONU have designed. A new DBA algorithm based on the full-service is proposed adapt to GPON. The simulation results from OPNET show this algorithm can satisfy the full service QoS requirements of GPON, and the algorithm has obvious advantages of each type of QoS protection service.(4) The research of WDM technology in optical network applications was present. This paper proposed a theoretical derivation for calculating the blocking rate of the basic unit. Analyzing the architecture of WDM-PON and WDM-TDM PON, and a novel classification method is proposed to divide the hybrid-PON into two catalogs:the time division multiplexing-based type and the wavelength division multiplexing-based type.(5) The topology of WDM-TDM hybrid GPON and the current type of service are discussed. A new method for classifying the priorities of service based on the frequency of service use is proposed. Then, the dynamic bandwidth allocation algorithm for the priorities of service was present. The simulation results show that the service QoS of using high frequency has been significantly improved and these algorithms are better than the traditional division.(6) The evolution of 10G GPON standardization is introduced.