Key Technique Study Of Signalling In Automatically Switched Optical Network

ASON signalling technique, which is one of the kernel techniques ofASON control plane, assumes the tasks of high efficient connection/callcontrol and fast protection/restoration management etc. This dissertation gives adeep study of signalling procedure optimization, fast protection/restorationsignalling process and component interactions of ASON control plane under differentrouting algorithms, via theoretical analyses, simulation experiments, and test-bedverification.This dissertation proposes a novel network resource optimization modelbased on traffic engineering theory in IP/ASON network. In this model,bandwidth of virtual topology in optical network is dynamically adjustedaccording to traffic intensity distribution, so that we can achieve the goals ofoptimized resource utilization and reducing network blocking probability.Simulation results show that this model has a lower traffic blockingprobability than the traditional fixed topology and bandwidth mechanismunder the circumstances of asymmetrical traffic distribution and networktopology.As one of the ASON control plane kernel techniques, survivabilitytechnique is the key to guarantee long period stable running of network. Anovel fast hierarchical subnet restoration method which could be used inlarge scale ASON is proposed according to the characteristic of hierarchicalrouting. This restoration mechanism adopts hierarchical signalling processand SPF routing algorithm, which greatly improve the efficiency of networkresource utilization while simultaneously reduce the restoration time.Numerical computation is carried out based on the data collected from theASON test-bed and the results show that in connection across multi-domainthis method has a lower restoration time than some other traditionalrestoration mechanisms.Based on the research work of survivability technique mentioned above,this dissertation gives a deep study on optimization design of ASONrestoration procedure under different routing algorithms given in ASONcorrelated standards, and the corresponding descriptions of control planecomponent interaction procedures. This part of work has already obtained theapprovals of ITU-T and provides a reference standard for the design andrealization of protection/restoration mechanism in ASON system.The study work of this dissertation is supported by 863 Program. In thisprogram the author designed and finished the ASON signalling system,realizing the basic ASON signalling functions, such as connection/callcontrol, protection/restoration management etc. Based on this work the authoralso participated in the work of building ASON test-bed. Several experimentswere also carried out to test the performance of ASON test-bed, includingnetwork blocking probability, connection setup delay, recovery probability etc,which further verified the performance of ASON and its signalling system.