The Research Of The Key Technologies Of SDH-based Automatic Switched Optical Network (ASON)

This dissertation is based on the research of National 863 Hi-tech Project -"Equipment Development and System Trial of Automatic Switched Optical Network (ASON)"(2003AA122120) and the WRI R&D project in 2005 -"Designing and Development of ASON Network Programming and Optimization Software (OTNPlanner)". These two projects aim to design and implement"SDH-based ASON equipment"and"ASON network programming and optimization software". So it is focused on the research of SDH-based ASON related key issues. The main contribution of this paper can be summarized as follows:(1) The survivability technologies of ASON. A new cooperation scheme between control plane and transport plane during the recovery procedure of ASON (bidirectional 1+1 dedicated protection, 1:1 dedicated protection with extra services) is proposed, and some conclusions based on the theories analysis are drawn. Some improved path restoration schemes—Forward Parallel Processing with Reverse Confirmation (FPC), Forward Parallel Processing with no Reverse Confirmation (FPNC), Bidirectional Parallel Processing with Reverse Confirmation (BPC), and Bidirectional Parallel Processing with no Reverse Confirmation (BPNC) are also proposed.(2) Based on the calculating and analyzing method of the resource requirements for shared-link path recovery, A heuristic algorithm of backup capability design for shared-link path restoration scheme is proposed.(3) ASON multicast and multicast recovery technologies. A Limited Multicasting the Nearest Tree-node First (LMNTF) algorithm is proposed, aiming at the networks constructed with the ASON nodes having limited multicasting capability. For improving the availability of multicast services, Break Tree-node Segment Restoration (BTSR) scheme is proposed. In this scheme, source node calculates the restoration path; using the connections existed in the"remained sub-tree"and"new sub-tree"created after the failure of multicast tree, it connects those disconnected sub-trees, so as to decrease the time consumed over the amount of cross-connect operations for new multicast tree constructing. It has been proved that BTSR can recovery those networks services with single-failures.(4) Carrying Ethernet services with multi-paths in ASON. Two key technologies for carrying Ethernet services with multi-paths in ASON—"VC virtual concatenation in SDH transport plane"and"Link Capacity Adjustment Scheme (LCAS)"are analyzed, and R&D schemes in actual ASON equipment are designed. And then an ILP formulation and a heuristic algorithm of routing design for carrying Ethernet services with multi-paths in ASON are proposed. The simulation work has been done.(5) ASON network programming and optimization software. Adopting Rational unified process, the ASON network programming and optimization software is designed. In this part, various ASON programming and optimization algorithms are deployed, including the heuristic algorithms proposed in this paper. The simulation work has been done.At last, the research work is summarized, and those potential research topics in future are discussed.