Research On Pedestrian-bicycle Ad Hoc Network Based On Multi-technology Communication

With the development of technology and economy,efficient and environmentally friendly communication methods have become the fashion that people pursue.A pedestrian-bicycle ad hoc network built by wireless devices carried by pedestrians and bicycles(cyclists)is an efficient and environmentally friendly communication method.Compared with traditional wireless networks,the pedestrian-bicycle ad hoc network faces problems such as different moving speeds,obstructions,wireless signal interference between devices and communication security.At present,the single wireless technology used in the pedestrian-bicycle ad hoc network cannot fully adapt to all communication scenarios.Therefore,the main research objectives of this paper include: finding problems by evaluating the effect of the single wireless technology in different communication scenarios of pedestrian-bicycle self-organizing network;designing an intelligent selection algorithm based on multi-technology communication according to the deficiencies of single wireless technology in different communication scenarios;proposing a physical layer encryption scheme to protect information security during communication.On the basis of the above research objectives,this paper mainly completes the following three aspects:Firstly,in this paper,Wi-Fi and 802.11 p evaluation systems are established using USRP B210 and GNU radio;Zigbee evaluation system is established using Zigbee nodes.According to the established evaluation systems,this paper evaluates the end-to-end link quality of Wi-Fi,802.11 p and Zigbee in typical communication scenarios of the pedestrian-bicycle self-organizing network such as no obstacle,obstacle occlusion and movement.According to the evaluation results,this paper summarizes the deficiencies of the single wireless technology in different communication scenarios.Secondly,according to the shortcomings of single wireless technology in different communication scenarios,this paper designed an intelligent selection algorithm for different communication scenarios based on multi-technology communication.This paper used the evaluation data in communication scenarios with obstacle obstructions.It also added the obstacle model in the NS2 network simulator to simulate the intelligent selection algorithm based on multi-technology communication.The experimental results show that the intelligent selection algorithm based on multi-technology communication is better than single wireless technology in throughput and frame delivery rate.Thirdly,in order to ensure the information security in the wireless communication process of the pedestrian-bicycle ad hoc network,a dual-protected physical layer encryption scheme was proposed for the Orthogaonal Frequency Division Multiplexing(OFDM)used by Wi-Fi and 802.11 p.First,the data field and signal field of the Physical Protocol Data Unit(PPDU)were iteratively time-domain encrypted to protect the data security.Then,the Long Training Symbol(LTS)after time domain encryption was used to prevent the enemy from performing channel synchronization.Finally,the encryption scheme was carried out through USRP B210 and GNU Radio in this paper.The paper also demonstrated the performance of the encryption scheme through the real hardware experiment and simulation experiment and carried out the security analysis of different attack scenarios.