Research On Impairment-Aware Routing ADN Wavelength Assignment Technology In Wavelength-Switched Optical Network

WSON (Wavelength Switched Optical Networks) is an evolutionary ASON based on WDM transport network, which evolves and develops the ASON control plane over optical transport network. WSON is extended to support the fiber/lambda automatic discovery in WDM and impairment-aware routing and wavelength assignment. With the maturation and application of WDM networking technology, WDM networks management are evolving to more intelligent. WSON introduces the control plane to WDM networks to realize the dynamic scheduling of network resource which make the scheduling of wavelength intelligently. The standardizing of WSON is advocated by IETF CCAMP group, it is an intelligent WDM networks standard. IETF CCAMP group commits to standardize the framework of WSON, the RWA information encoding, the extension of the OSPF protocol, the extension of the signaling protocol. The wavelength-continuity and physical layer impairments constraint the routing and wavelength assignment, the impairments accumulating along the lightpath may degrade the quality of the optical signal, even more, have the lightpath be blocked. In most researches, the physical optical layer was assumed that it has the ideal capability of transmission, meanwhile, the proposed impairment-aware routing and wavelength assignment (IA-RWA) algorithms focus on the research in the single-domain single-granularity switching optical network. With the increase of the network scale, there are new requirements for IA-RWA in multi-domain multi-granularities network.This paper researches on the critical issue on WSON, which includes the control plane controlled by GMPLS and its implementation in WSON. PCE-based centralized control Plane calculates the lightpath for the request. The main contributions are listed as follow:A novel ROADM encoding based Sub-TLV is proposed to improve the encoding efficiency. This part of paper research on the architecture of ROADM and the encoding of Sub-TLV.An efficiency routing and wavelength assignment algorithm is given for impairment-ware lightpath calculation, considering that researches lacked for the impairment-aware RWA algorithms.The multi-granularities routing algorithm based on failure type is shown in this paper to satisfy the requst raised in multi-domains and multi-granularities network, which can improve the restoration probability.