Research On Openflow Based Adaptive Dynamic Bandwidth Aggregation Technology

3GPP defines that wireless terminal may simultaneously access multiple wireless networks to achieve the purpose of higher bandwidth with lower cost. This is called multi-access bandwidth aggregation or multipath(otherwise it is singlepath). Traditional research on bandwidth aggregation technology focuses on the data plane which designed to improve the transmission efficiency of bandwidth aggregation. The research work of this thesis focused on control plane of bandwidth aggregation, the purpose is to improve the throughput of the system under the premise to meet the Qos of terminal by configuring a wireless terminal associated mode(single-path or multi-path) with a reasonable way, which can be interpreted as a optimal proble towards to associated, it also can be interpreted as each terminal linked to network by which association way can make the system optimization. This thesis completed the system design with OpenFlow based on the characteristics of OpenFlow separates control and data planes and our work is focused on the control surface. Specifically, the thesis works in the following two aspects:(1) The system design of dynamic bandwidth aggregation based on OpenFlow. Since the changes of the RSSI value and the number of station of the wireless environment cause the changes of network topology frequently, we need to dynamically configure the association mode of terminal so that the wireless networks can get the optimization association at any time. Therefore, the system architecture includes two functions: One is designed the communication protocol to collect and monitor network status based on OpenFlow standard to provide the data for the optimal association model; another is designed the protocol of configurate association based on OpenFlow protocol enables the terminal to change their way of association after obtain the results of optimal decision. Overall, the terminal is connected through a dynamic control approach to achieve the purpose of optimization association of the system.(2) The model of the policy of the optimal association. The decision goal of the traditional association is maximize system benefits and the decision result is single-path. The objective of this study is maximize system throughput under the protection of the terminal Qos and the decision is multipath or single path. The end result is that system can meet terminals’ Qos through different association ways under different network conditions which reflects the adaptive capabilities of the terminal. Our work includes three areas based on these goals: First, the model of the throughput of terminal is proposed for the purpose of providing a theoretical basis for maximizing the throughput of the system, which is by analyzing the influence of the signal strength and the number of the terminals to single terminal’ throughput. The second is construct nonlinear integer programming model which is based on the premise of protecting the terminal Qos demand and maximizing system throughput. The third is to use interactive tool Lingo to s implement this model.The proposed system architecture and the model is able to change the association way of the terminal by the network topology and guarantee the Qos of the terminal to adapt the network conditions. Finally, we configured simulation scenarios to verify the results of adaptive and dynamic decision algorithm of bandwidth-aggregation clearly superior to other conventional algorithms, and study a variety of factors which affect the algorithm.