Mapping the location of 2.4 GHz transmitters to achieve optimal usage of an IEEE 802.11 network

This paper describes the use of a low cost 2.4 GHz spectrum analyser, the MetaGeek WiSpy device, in conjunction with custom developed client-server software for the accurate identification of 2.4 GHz transmitters within a given area. The WiSpy dongle together with the custom developed software allow for determination of the positions of Wi-Fi transmitters to within a few meters, which can be helpful in reducing the work load for physical searches in the process of surveying the Wi-Fi network and geographical area. This paper describes the tool and methodology for a site survey as a component that can be used in organisations wishing to audit their environments for Wi-Fi networks. The tool produced from this project, the WiSpy Signal Source Mapping Tool, is a three part application based on a clientserver architecture. One part interfaces with a low cost 2.4 GHz spectrum analyser, another stores the data collected from all the spectrum analysers and the third part interprets the data to provide a graphical overview of the Wi-Fi network being analysed. The location of the spectrum analysers are entered as GPS points, and the tool can interface with a GPS device to automatically update its geographical location. The graphical representation of the 2.4 GHz spectrum populated with Wi-Fi devices (Wi-Fi network) provided a fairly accurate method in locating and tracking 2.4 GHz devices. Accuracy of the WiSpy Signal Source Mapping Tool is hindered by obstructions, interferences within the area or non line of sight.