Research Of Services Oriented Next Generation Optical Network Architecture

The emergence of Intelligent Optical Network (ION) has very important influence on the development of services based on optical network. But with the dramatic increase of Internet services, data has been the dominating traffic in optical network. On the other hand, the character of future users' demand becomes more and more diverse and complex. So how to provide services fast and support them strongly has been an urgent problem. ION has conducted some beneficial attempts in this field, but it still has some problems when processing complicated service logic. Under the support of the 863 Program of China and National Nature Science Fund of China, the author has investigated Service Oriented Next Generation Optical Network (SONGON) systematically and detailedly. Our work focuses on the four essential issues: the construction of service plane, the key support technologies of optical network services, the development and convergence of optical switching mechanisms and the building of testbed. Many corresponding schemes and algorithms are provided, which are verified to be feasible and efficient by simulation tests.Today we have many innovative researches of SONGON, which are listed as follows:1. The architecture of Service Oriented Next Generation Optical Network is proposed, which introduces service plane to original ASON (Automatic Switched Optical Networks) framework and can achieve the separation of service switching from service generation and the independence of service generation to service operation environment. It can increase service operation efficiency and realize service customization by the classification and distribution of different granularities of service functions. Service plane can support the access of application to network core resources and the operation of the third part service developer. So the development of new service is quickened. Service plane also helps to coordinate the trust and interconnection of different management domains and optical networks with different switching mechanisms. The application of service plane can realize adaptive service access, adaptive service reconfiguration and adaptive service customization.2. The optical multicast resources optimization method by Genetic Algorithm is proposed. There are some problems about optical resources optimization when multiple multicast traffics coexist, which include multicast routing in sparse splitting optical network, multicast grooming with static state and semi-dynamic multicast setup. In these problems, it can optimize network resources through arranging the calculation order of traffics by Genetic Algorithm. On the other hand, a multicast protocol supporting traffic grooming in ION is provided and the message type, signaling flow and state machine model are given. Simulations show that traffic grooming can decrease the blocking probability greatly.3. A novel multicast switching structure is studied. In this structure, optical splitters and wavelength converters are shared by all input ports and output ports. To accommodate this change, a new multicast routing algorithm is designed and a Link Weight Changing (LWC) policy to balance network traffic is provided. Simulations show when the number of shared splitters and converters changes within a certain degree, the performance of multicast traffic will not change much. So it is reasonable to reduce splitters and converters to a certain extent and at the same time guarantee the traffic performance. Simulations also show LWC policy is of benefit to decreasing blocking probability.4. The application of Advance Reservation Service (ARS) in optical network is studied. In order to achieve ARS in ION, the related protocols of GMPLS (Generalized Multi-Protocol Label Switching) are extended. At the same time, three routing and wavelength assignment algorithms which are Shortest Path (SP), Link Weight Changing (LWC) and Layered Graph (LG), and the mechanism to classify shared wavelengths and dedicated wavelengths for NonAdvance Reservation Services (NARS) are proposed. Simulations show LG is best with low traffic loads.5. A Hybrid Optical Switching (HOS) structure is proposed, in which Optical Circuit Switching (OCS) and Optical Burst Switching (OBS) can be implemented simultaneously. At service access point, different traffics are processed by OCS or OBS according to their characters to make full use of resources and reduce processing overhead, which is also the function of adaptive service access. In HOS, optical buffer and deflection routing mechanisms for OBS are introduced to solve the contention of bursts, and the wavelengths classification mechanism is proposed to make some wavelengths dedicated to OCS and guarantee the performance of OCS. Using Queue Theory, the mutual performance influence between OBS and OCS is analyzed and compared with simulations. The results got by theory analysis are in agreement with simulations. On the other hand, when different OBS network domains are connected by OCS networks, two resources allocation algorithms are provided, which are Time Driven Resources Allocation and Traffic Driven Resources Allocation.An ASON control plane protocol stack is also setup. The service plane is firstly developed on the basis of control plane and some parameters are measured. This work will help much to the design of future real system.