Protection Architectures Based On Synchronous Digital Hierarchy

With the rapid development of Wavelength Division Multiplex, the role of Synchronous Digital Hierarchy (SDH) in toll network has greatly changed. Therefore traditional optical network protection is not enough for the newly arising needs. The new network protection technique is one of the most popular research directions of optical communications.The thesis analyzes the basic theory and traditional protection techniques such as Sub-Network Connection Protection (SNCP), Multiple Section Protection, MS-SPRING etc. The working theory, implementation and the disposal flow of software are discussed respectively.To overcome the shortcomings of the traditional techniques, a new mixing protection technique is put forward, which aims at SDH multiple operation platforms. This new technique fuses SNCP and MS-SPRING, actualizing the two protection techniques within the same ring of optical network and achieving great effect. The new technique, which is compatible for not only high-path but also low-path business, solves the problem of SDH multiple operation platforms.