Research On The Application Of Automatically Switched Optical Network

The framework of modern optical communication was established in 1966, when two British scholars, C.K.Kao and G. Hockham, proposed a groundbreaking concept of "transmission medium". In the past few decades, optical communication has enjoyed significant technological developments. Digital transport systems were developed, from Plesiochronous Digital Hierarchy (PDH) to Synchronous Digital Hierarchy (SDH). In recent years, new technologies such as Multi-Service Transport Platform (MSTP) and Automatically Switched Optical Network (ASON) have been developed. There are three general trends in the research on optical network. In terms of form, it is integrating transmission and switching together. In terms of hardware, it is evolving into an all-optical network, and in terms of software it is becoming increasingly intelligent.ASON, in which switching is automatically controlled by routing and signaling, is broadly considered the mainstream technology of the next generation optical network, and major service carriers have already started building their own automatically switched optical network. This thesis analyzes the necessity of ASON implementation, compares it to conventional optical network, and concludes that ASON is completely feasible. However, a successful implementation of ASON requires thorough understanding of ASON's key technolgies and core protocols. This thesis researches three key technology know-hows in ASON, namely, signaling, RSVP-TE protocol, and OSPF based routing protocol. This research will help us understand the working principles, protection schemes, and recovery mechanisms of ASON, which are fundamental knowledge in ASON applications.This thesis reviews the standards and developments of the current ASON equipment. All domestic communication carriers have already announced their ASON equipment based on SDH together with their demo optical network. This thesis researches construction plans of ASON, and proposes a solution to smoothly transition from current network to ASON by maximizing the use of current available equipment and introducing ASON equipment. This thesis also conducts a analysis of feasibility of integrating Metropolitan Area Network (MAN) with an ASON with two layers of switching functions.Finally, this thesis researches future directions of ASON development, and concludes that ASON is an inevitable future of communication network. As its maturation of equipment, standards, and software, ASON will be adopted commercially at a broad scale.