Research Onservice Adaptation Technology Under Ubiquitous Network Environment

Along with the growing number of intelligent equipment appeared in the network edge and customers all around through the cable or wireless access way, the Ubiquitous Networks is evolving towards a direction that featured with variety of terminals, high-bandwidth of information transmission, diversity of content elements and intelligent of service provided ways. This brought a higher demand on the terminal and network capabilities. On the one hand, it needs to achieve efficient control of the heterogeneous integration of network resources, and build more powerful smart interoperability terminal equipment system, breaking the single network capacity, to achieve a more efficient service transfer scheme and to provide users with best and seamless service experience; on the other hand, in order to achieve heterogeneous nodes dynamic self-organizing, it needs to solve the context-aware, the heterogeneous network/terminal cooperative transmission, mobility management, service adaptation and synthesis as well as security and other key issues.This paper focus on service adaptation under ubiquitous networks environment. The service adaptation here refers to that the service provider can perceive the changes of network and terminal capacity, and then appropriately adjusts the resources offered to the service to adapt to different network. At the same time it adjusts the service content according to different user preferences, to maintain service continuity, guarantee service quality and user satisfaction during users roaming and moving process.In this paper, first it describes the IMS control-based service adaptation framework and its advantages. Then combined with context-aware service selection technology, it proposes context-aware service selection framework based on adaptive genetic algorithm (GA). After designing the process of service selection using GA, we analyze the performance of GA by simulation to prove it is a good solution to solve the multi-objective decision service selection problem with the load balancing performance and better convergence. Next, we study the transmission adaptation scheme under ubiquitous networks. It is proposed an adaptive vertical handover scheme based on mSCTP-CMTPP path-measurement during WLAN and UMTS. By measuring the two-path bandwidth and receiving end blocking rate, it can adaptively select the more optimal transmition mechanism. Through modeling analysis and simulation, it proves mSCTP-CMTPP can bring good handover performance. Finally, against the existing transport layer VHO technology, it is proposed the cross-layer handover prediction method based on context-aware, which uses the context-aware information as the basis of the judgment. The mechanism is verified by simulation can effectively reduce the handover delay and increase the throughput during handover, which has a certain significance on cross-layer handover research.