AEPSO-Based Protection Capacity Assignment Algorithm Adapt To Multi-services In ASON

With enduing traditional optical transport network with unprecedented flexibility and expansibility, ASON (Automatically Switched Optical Network) represented the future direction of next generation optical networks. The support to many kinds of restoration strategy is an important characteristic of ASON, is also a focal point in ASON studies at present. Now with the capacity of the network increases rapidly, the research on intelligent dynamic restoration algorithm is significant to improve the survivability of ASON. By a perfect restoration algorithm, the spare network resource utilization and failure restorability can be raised more rationally and effectively. Thus the social influence and economic losses caused by the network faults can be reduced evidently.These acknowledged advantages of ASON including:providing service quickly,providing multi-protection/restoration strategy and providing new service type etc, whereas providing multi-protection/restoration strategy is so focused question that merchant plan to construct ASON net.Be differ from protection/restoration strategy of traditional optical transport network, the survivability request of ASON embodiment mainly considering reasonable spare resource assignment whole, meeting multiform restoration demand sufficiently,expansibility of algorithms etc.As an improved PSO(Particle Swarm Optimization), AEPSO(Self-Adaptive Escape Particle Swarm Optimization) Considering that the organisms have the phenomena of escaping from the original cradle when they find the survival density is too high to live, this paper uses a special mutation -escape operator to make particles explore the search space more efficiently. The novel strategy produces a large speed value dynamically according to the variation of the speed, which makes the algorithm explore the local and global minima thoroughly at the same time, to deal with the problem of premature convergence and slow search speed in order to solve combinatorial optimization problems efficiently. Considering Protection Capacity problem is in essence a combinatorial optimization problem.Under satisfying the demand that different businesses injured can be restored 100 percent possibility fastly and parallelly,The focus of the algorithm is to assign the spare resource in networks more rationally with the objective of solving the problem of optimizing spare capacity.The thesis studies and analyses the relevant technology of protection capacity problem in ASON, including the routing architecture of ASON, the dynamic routing and wavelength assignment technology in ASON and the principle of AEPSO. And a model about protection capacity assignment algorithm adapt to multi-services in ASON is presented and structured based on AEPSO. With above-mentioned relevant technology, a simulation platform is designed to test and improve the algorithm. The main achievements are as follows:(1) The routing technology and architecture of ASON network are analyzed and summed up, which include route scheme, distributed wavelength assignment, signaling routing protocol and routing distributing topology, etc. The influence factor and key technology relevant to realize protection capacity assignment algorithm in ASON are also analyzed in details(2) Mathematic model is established by abstracting ASON's protection capacity assignment problem,which is the foundation of applying AEPSO to ASON's protection capacity assignment problem.The mathematic model depict the ASON's protection capacity assignment problem scientific and effective,and make the explanation,application, mathematic analysis of this problem.(2) By studying the principle of AEPSO, a novel protection capacity assignment algorithm adapt to multi-services based on AEPSO is firstly presented. In the algorithm, different businesses can be processed parellelly and processing of routing and wavelength assignment sub-problem can be paralleled as a whole. It is able to consider network resource and priority of different businesses synthetically. Compared with other protection capacity assignment algorithm based on IP (liner programming) or GA(genetic algorithm), the algorithm can attain better near optimization solution ,best time effiency, the solution is definitely satisfactory in engineering.(3) Programming is done to realize AEPSO-based protection capacity assignment algorithm adapt to multi-services in ASON. The calculation environment of network is simulated. Based on the simulation system, AEPSO is compared with other algorithms mentioned in references to verify the performance of different algorithms. (4) The performance of restoration alrotithm based on AEPSO is simulated. According to the results, combination of different parameters are adapted, which make the algorithm get better result at the least resource expenses.