Resource Coordinate Scheme In Optical Network Under The Restriction Of Wavelength Continuity

Recently, from core network to metro network, optical transmission technology has replaced the traditional technology to become the foundation of transmission network. Using the fiber as transmission media, this technology has efficient transmission ratio, wider bandwidth and strong stability. Optical network is also the direction of the network development in future. As the price decreased, optical transmission technology has been used in access network, thus the size of network will increase rapidly. With the generalized multi-protocol label switching (GMPLS) protocols, this huge size optical network can be managed under the control plane. Through resource management, link protection and services configuration, the whole network can be connected with IP protocol. However, these technologies are not perfect currently. Influenced by price and capability, some works have to be completed by electrical equipment through optical-electrical transformation. It obviously reduced the network flexibility and efficiency. In order to limit the transformation, the wavelength which was use by connection should keep the continuity to pass the nodes. In this paper, some research works have been conducted as follows:A wavelength assignment algorithm has been proposed in this paper, by concerning the path length as a parameter, this algorithm can make full use of the network resource and improve the possibility of successful connection establishment. To deal with the resource contention in the process of backward wavelength reservation in RSVP protocol, a contention resolution based on distance has been proposed. By comparing the distance on the remainder route of the conflicted service requests, the resource would be distributed the one which is closer to its source. With this method the blocking probability in the network can be reduced.After adding the wavelength convertor, the switch capability in optical network is improved. But as the size of network expanding, the work load of routing will also increase. For providing the sufficient routing capability, topology aggregation can be used to simplify the route process with the sub-domain routing technology. Considering the feature of wavelength convertor, some modification of the original aggregation algorithm has been proposed in the paper to provide more accurate topology information for path computing.