Design And Implementation Of Mobile Data Offloading Scheme Based On Femtocell

Mobile data offloading is a new technology emerging to deal with the explosive growth of mobile data recently, which is a research focus of computer network nowadays. Mobile data offloading makes use of complementary network technology to offload the data flow of cellular networks so as to migrate the network load, improve the experience of users and reduce the cost. This thesis design and implement a mobile data offloading scheme by analyzing the network architecture and existing function module of the developing Femtocell equipment. After that, we analyze the actual effect, total system bandwidth and average network delay of the scheme.First, we present the basics of Femtocell technology, including the motivation, developing status and standardization. Then we make a brief introduction of mobile data offloading, including research background, state of the ant and the significance and then analyze the characteristic of the popular network technologies that are used in mobile data offloading.The existing research of mobile data offloading mostly focus on network switching when comes to the availability of cellular network and complementary network, that is to develop strategies of choosing and switching between different networks according to the evaluation of network status, characteristic of data packages and preference of operators and users. This thesis designed and implemented a mobile data offloading scheme which made use of 3G and Wi-Fi interface in parrel considering the characteristic of Android system and Femtocell so as to improve the system bandwidth while reducing the load of the cellular network at the same time. This thesis mainly includes handling of physical communication interface, capture of application data packages from upper layer, definition of control protocol, implementation of function module and interface selection and data amount allocation strategy.To deal with the network selection problem of mobile data offloading scheme making parrel use of multi communication interface, we adopt the idea of multi-objective decision. By take overall consideration of the influence of different network parameter, we choose the better communication interface using TOPSIS; for the allocation of data flow between different physical communication interface, we refer to the thought of optimum seeking method and decide the ratio of data that allocated between physical communication interfaces by experiments, in which we set maximizing the bandwidth as the main target and considering the interface utilization ratio and network delay as well. While transferring the data packages, we propose a scheduling algorithm to distribute data packages through different interfaces by taking into account the bandwidth utilization and load balance.The experiment results shows that the scheme designed and implemented in this thesis enhances the total bandwidth while offloading the data flow in the cellular network so as to mitigate its load. It also optimizes the average network delay compared with the offloading method using single physical communication interface.