Research On Several Key Technologies Of Virtual Terminal System In Wireless Ubiquitous Networks

Wireless ubiquitous networks, form with the development of wireless technologies, provideconvenience for data and services, but bring great challenge to the cooperation of different networksand devices. As a new technology, virtual terminal solves the problem efficiently. Virtual terminalmeans devices in different networks become one big terminal through cooperative communicationin wireless ubiquitous networks environment, so as to provide various services and high QoE forusers. In this dissertation, the system architecture, device discovery mechanism and resourceoptimization strategy of virtual terminal system in wireless ubiquitous networks are researched, andsome related problems are discussed. The major works are as follows.Firstly, the basic concept of virtual terminal system is introduced and researches of keytechniques are summarized. Then the problems and future research direction are proposed.Secondly, a system logic architecture based on the layered cooperation is proposed. The virtualterminal environment is divided into four layers and they are defined detailed. Then the logicrelationships between them and the service procedure are described. Analysis shows that theproposed architecture can schedule resource in service oriented manner.Thirdly, a device discovery mechanism of virtual terminal system based on Bluetoothtechnology is proposed. Based on Bluetooth technology, the device connection delay is optimizedadopting back off algorithm and the BTCP scatternet formation algorithm is improved. At last thedevice discovery strategy based on dynamic topology is given. The simulation results show that theproposed algorithms can reduce the connection delay effectively and adapt to the actual networkenvironment.Finally, a joint optimization algorithm of resource and power based on multiple-flow mode isproposed. The joint optimization model of network load and power control based on servicemultiple-flow is established and then divided into two sub-problems. The optimization of serviceand power allocation is solved and the simulation results show that the proposed algorithm isefficient in network resource optimization on the basis of ensuring network load balance.