Research Of Mobile Handover Optimization And Secure Communication Of 6LoWPAN

With the popularity of the Internet of Things(IoT) technology,the topology dynamic characteristics led to unprecedented mobility problems. How to make the node carry on efficient handoff in movement or data transmission become the urgent problem to be solved. There will be more accessing and handoff operations in the mobile network, meanwhile, data security issue become an important factor need to consider.Combined the mobility of next generation network with neighbor discovery mechanism of IoT, we propose a mobile accessing method using neighbor node discovery auxiliary mechanism, and then implemented local IoT communicating in IPv6 and meet the demand of mobile handoff. On this basis, we designed access control for nodes, which is the implementation of access authentication, and encrypted the data transmission using advanced encryption standard. The scheme secured mobile communication scheme while ensuring the transmission efficiency. The contributions of this paper are listed as follows:(1) Implementation of 6LoWPAN discovery auxiliary mobile handoffThe implementation scheme of the new generation IoT protocol(6LoWPAN) was proposed, which combined 6LoWPAN mobile nodes, access nodes and gateway etc. Based on the Contiki system, we designed a lightweight and efficient mobile handoff scheme, and improved establishment and maintenance of topology in RPL protocol of 6LoWPAN. In the construction and maintenance process of the RPL directed acyclic graph topology, the real-time received signal strength would be analyzed, prejudge the dynamic trend of the network. Combined the received signal strength with time delay and other parameters, we implemented pre handoff mechanism using event-driven programming method of Contiki system. After the test of hardware experiment, we tested and analyzed the network performance in Cooja simulator based on Contiki system. The results showed that this method improved mobile accessing efficiency and packet loss rate when compared with the original 6LoWPAN method.(2) Access authentication and encryption based on 6LoWPANBased on IoT platform and Contiki system, we contrasted and tested a variety of typical encryption algorithms, realized the advanced encryption standard on CC2530 nodes, which encrypted the payload of the network packets and combining the access authentication of wireless node to implement the secure mobile communication in IoT.(3) Integration test and analysis of security mobile schemeWe built a platform with SM2530 which based on CC2530, and completed the test and analysis for improved Contiki system with security mobile scheme in real environment, then carried out a simulation experiment with large scale nodes network in the simulator, and finally tested the performance of the system. Combined with previous mobile handoff scheme, we tested and evaluated the feasibility and efficiency of integrated solutions, perfected the IoT terminal communication process.In the last, we summarized the research of this paper, and analyzed deficiency. Then we pointed out the issues to be solved.