Design And Simulated Implementation Of Intelligent Qos Guarantee Mechanism With Abc Supported

NGI (Next Generation Internet) will be more convenient and timely, and anything will possibly become part of networking life when high-speed Internet can be accessed with any devices at anytime anywhere. Therefore, the concept of ABC (Always Best Connected) comes into being with providing more flexible and diverse network services with higher QoS (Quality of Service). However, some characteristics of NGI, such as heterogeneity, mobility and instability, make troubles for providing reliable QoS. As the results, many protocols, network architectures and implementation mechanisms need to be reconsidered and redesigned. In this thesis, an intelligent QoS guarantee mechanism with ABC supported is designed to provide ABC's services and keep user's QoS in the course of communication with the NGI environment.NGI combines many types of wired and wireless networks. Therefore, for the network model design, it is necessary to consider heterogeneous multi-segment multi-provider sub-networks where the user's preference is used for user's flexible and diverse application requirements, and at the same time uncertainty of network information and fairness of decision are also considered to keep the ABC characteristic in the communication process.In this thesis, mechanisms such as resource reservation, rerouting and QoS negotiation are used for ensuring the end-to-end QoS. Firstly, the reservation operation for searching the candidate cells will be started if the necessary condition is met after the user connects with the current cell. Then, resource reservation algorithms will be performed to select the optimal cells, find corresponding reserve strategies and reserve status. Finally, the rerouting paths from the access routers of reserve cells to the destination node will be established, and the resources in the found paths will be reserved. In the above process, QoS negotiation is used if the QoS requirement of user cannot be met.The above mechanism is implemented and the performances are analyzed based on NS2 environment. The simulation results show that the designed mechanism not only can deal with uncertainty of network information and achieve the win-win between user and network providers but also can more effectively ensure user's QoS in the communication process.