Research And Implementation Of Key Technologies For Handover In Heterogeneous Wireless Networks Based On SDN

In recent years,with the rapid development of wireless communication network technology,different wireless access technologies have emerged and more complex heterogeneous wireless networks have been formed.In order to ensure that mobile nodes can access different wireless communication networks in time to enjoy diversified services,mobile nodes must be able to seamlessly and efficiently conduct handover in complex environments of heterogeneous wireless communication network.Therefore,high demands have been raised for handover in heterogeneous wireless networks.Handover in traditional heterogeneous wireless network relies mainly on mobility management protocols such as MIPv6.Multiple signaling must be exchanged between different devices,which results in network resources waste and inefficient handover.Because SDN(Software Defined Network)can have a global view of the topology through acquiring information of network devices and conduct flexible network control and management.Executing handover in heterogeneous wireless network based on SDN can solve the problems of traditional handover and turn into an alternative.So research and implementation on key technologies of SDN-based heterogeneous wireless network handover are of great value theoretically and practically.Handover in heterogeneous wireless network based on SDN is essentially the dynamic matching of a wireless network for mobile nodes.Therefore,this paper divides the entire handover process into three phases: information gathering,which collects the location information of mobile nodes and calculates network status in heterogeneous environments;handover decision making,determines whether to perform network re-matching based on the information of the mobile node,or formulates a re-matching decision based on the heterogeneous network status;the handover execution is based on the handover trigger and the decision making procedure.The controller executes and completes the handover operation by sending flow table.On the basis of in-depth research on heterogeneous wireless network handover and around the above key technologies for handover,the main contents of this paper are as follows:1)Design and implement a SDN-based information collection approach,including obtaining the location of mobile nodes,topology,and network status information such as bandwidth,delay,and packet loss rate of the heterogeneous wireless network.2)Further,a mobile node location management scheme is designed and implemented for handover triggering,and a responsive handover approach to perform handover.Simulation experiments show that compared with the baseline handover scheme SSF(Signal Strength First),the handover delay,packet loss rate and signaling cost of the proposed proactive handover scheme are improved in the case of the network re-matching decision making with the simple linear mobility mode.3)Design and implement a handover scheme based on SDN and multi-attribute decision making to optimize and replace the network re-matching scheme in simple linear mobility mode.The experimental results show that the handover delay,packet loss rate and signaling cost of this solution are improved.In addition,the proposed approach can also select the best candidate network for the mobile node according to different communication business types.