QoS Mechanism And Realization In 3G MSC

With rapid development in 3G evolution, and convenience,flexibility,larger capacity,coverage ability in Mobile Communication, 3G Mobile Communication will not only substitute a lot of fixed network speech services, but also evolve into a colorful radio world. All those enhancement services with voice,images and words greatly increase amount of service and data stream in the network, and interaction among subscribers grows more and more real-time and lively. Therefore, it is highly requested that network have higher quality. For those applications which have special demands for bandwidth,delay and jitter, it's obvious that the current"DO BEST"service is not enough. QoS (Quality of Service) appears under such background. The aim of this thesis is to study and realize QoS handling mechanism used by 3G SGSN in UMTS network, some control policy and related arithmetic are taken to reach to such purpose. All these strategies can efficiently provide ent-to-end service quality control and ensure the subscribers'applications according to subscribers'service need and network bandwidth. Furthermore, they make service can be satisfied to reach to resource guarantee need provided by network.Firstly, this thesis introduces the basic concept of QoS and requirement in 3G network under the background in Mobile Communication System, and gives a description of the QoS models used widely now. Considering all these models, Alcatel brings forward its solution. Then according to the UMTS network characteristic, it depicts application of QoS in UMTS network, including service level definition,DifferServ Model explanation used by UMTS network,DifferServ service type definition, etc.Next this thesis describes the QoS architecture in UMTS network, which puts forward a standard to all equipment manufacturers, it will make all manufacturers realize QoS concept and control strategies normatively. Above all, it will ensure higher quality of end-to-end network QoS.Finally, it puts more emphasis on the study and discussion on control plane and user plane QoS handling mechanism in Alcatel SGSN. How does control plane handle QoS? How to solve QoS parameter negotiation problem when QoS parameters are transferred among all network elements(such as RNC,SGSN,GGSN, etc)? All these questions are important and difficult issues. In order to guarantee QoS in user plane, network elements in UMTS make use of arithmetic and handling strategies, traffic management,congestion management and so on. In addition, it also gives some research about how to get rid of SGSN compatibility problem from 3G to 2.5G., because 3G SGSN is developed based on 2.5G SGSN, it's demanded that 3G SGSN not only recognize 3G subscribers service, but also handle 2.5 application service. This also makes protocol conversion,parameters recognization,consistence check are key issues during research and design process. These good solutions and implementation for all key issues provide the high quality of QoS software design in...