The Research About Wi-Fi Network Monitoring And Wireless Terminal Positioning System

WLAN provides a convenient way for us to access to the Internet meanwhile theWLAN users suffer from security pressure because the transmission medium of WLANis open and it is vulnerable to be attacked for802.11protocol weakness. Handhelddevices with Wi-Fi access capability become an unsafe factor themself when they arebrought into important areas such as the database of a bank. One of the chief problemsWLAN faces is how to detect and discover those devices and monitor the networkenvironment and the actions of attacks. So it is necessary to own a monitoring systemfor wireless local area network which can provide guidance for network planning,management, deployment and detect unsafe factors in the network in order to maintainthe network running safely and effectively; On the basis of the existing WLANresources it is possible to provide an indoor location service without adding otherhardware. Wi-Fi fingerprint positioning can be realized on the existing hardware andprovide high precision locating. Main contributions of this paper are as follow:1. Wi-Fi network monitoring system is designed by wireless network technologyand embedded technology. It includes hand-held tester and PC monitoring server. Whenauthorized the user can get real-time information such as network bandwidth、wirelesstopology、traffic information as so on.2. The software of Hand-held tester is realized by embedded QT technology. basedon802.11protocol standard we extract Radiotap header、management frame and dataframe to analysis wireless network running status information. Meanwhile thehand-held tester can upload test information to server for fusion data analysis and thatcan give us a wider range、higher levels of overall network status information..3. The software of PC is based on WPF and communicates with handled testerusing C/S mode. This paper designed the communication protocol for both sides and didthe detailed functional test and analysis for Handled tester and server.4. In order to enhance the positioning accuracy an improved matching algorithmwhich is called SSOI is proposed in this paper. The algorithm is based on fingerprintlocalization but combined with the reference of AP’s intensity sequence information in order to improve the positioning effect. Compared with other algorithms, SSOImatching algorithm can improve the positioning precision without increasing calculatedamount, and the algorithm shows good effect in the simulation and the actual demoapplication.