Research Of Packet Forwarding Technology On Programmable AP

Programmable functions and virtualization features are referred as prospective key techniques for the fifth generation mobile communication network(5G),which can be combined with the existing SDN and NFV technology to abstract and unify network and infrastructure resources,improve the utilization of network resources and simplify the complexity of network,and become one of the research hotspots in the Software Defined Wireless Network(SDWN).However,the implementation of virtualization technology brings additional consumption of I/O,storage and processing resources on wireless devices,resulting in a significant degradation in forwarding performance of AP.Therefore,it is of great significance to improve the packet forwarding performance on programmable AP.Aiming to improve the performance bottleneck of virtualized AP,this thesis mainly studies the fast forwarding technology of packet to improve the forwarding performance on programmable AP device.Firstly,in order to solve the performance loss caused by the packet reception mechanism in monitoring interface,this thesis proposed a wireless frame receiving interface based on DebugFS technology,which can receive virtual BSSID frame through modifying the mask value of wireless network card in real time.Secondly,to solve the problem of forwarding performance degradation caused by the packet processing in user space,a fast forwarding method is proposed to decomposes the processing task of wireless frame.By distinguishing the type of frame,the data frame and the management frame are processed in user space and kernel space disparately,which can realize the separation of the user management and the data forwarding.Finally,in order to improve the forwarding performance of the data frame,this thesis transplantes the functions of hostapd into the agent in C lick to maintain station information at the same time,which can realize seamless handoff and network service quality guarantee.The proposed forwarding technology presented in this thesis are implemented in the " Basic Experimental Facility of Future Network " —SDWN testbed and a series of experiments have been done in the experimental bed.The experimental results show that the method of packet forwarding designed in this thesis can provide reliable communication,low transmission latency and high link bandwidth for mobile terminals.The proposed forwarding technology can improve the forwarding performance of the programmable and virtualized AP effectively,and provide the key technical support for future research in Software Defined Wireless Network.