| At present, optical networks are carrying more than80%telecommunicationtraffic. With the increase of new kinds of services and the growingrequirement of bandwidth, the scale of networks is increasing rapidly, whichnot only makes the cost of centralized management and control larger andlarger, but also make adaptable and grooming of multi-granularity more andmore difficult. Therefore, the conception of multi-domain multi-layer opticalnetwork is introduced to solve the problem of management and deploymentfor network resources.Path computation element (PCE) is one of the core technologies inmulti-domain multi-layer optical networks. The main function of PCE is tocompute the optimized inter-domain paths efficiently by holding limitedinformation from other PCEs. However, there still exist some problems aboutthe new technology. One the one hand, the path computation with policy andconstraints can’t obtain desired network performance; on the other hand, thearchitecture of PCE-based multi-domain multi-layer optical networks stillneeds to be perfected, for example, the PCE communication protocol (PCEP)which supports multi-granularity, concurrent and protective services needs tobe extended, PCE-based GMPLS protocol suite needs to be developed.Based on the problems mentioned above, in the dissertation we will studyrouting algorithm, PCE communication protocol and signaling process inmulti-domain multi-layer optical networks. The research achievements areshown as follows.First, routing algorithm in multi-domain optical networks will be studied.We will propose a hierarchical PCE-based inter-domain routing algorithm,which obtains the balance between the network performance and the resourcecost by introducing k random paths (KRP). The simulation demonstrates thatthe proposed algorithm outperforms conventional methods in term ofblocking probability and resource utilization. Second, the PCEP in multi-domain multi-layer optical networks will bestudied. We will propose the extended solution of PCEP which supportsmulti-granularity and concurrent services and services with1+1protection;finally, we will design and realize the PCEP with C programming, whichsupplies PCEP system to be applied in multi-domain heterogeneous opticalnetworks.Third, the application of PCEP will be studied on experimental platform.We deployed the extended PCEP to a10-node platform which consists ofSDH and OTN equipment so as to check the function of PCEP. Furthermore,PCEP is applied to a1000-node multi-domain multi-layer simulation platform,which can prove flexibility and scalability of the extended PCEP. |
