When installing Wi-Fi connected devices in buildings, Wi-Fi signal strength is the first and most basic question which comes to mind – can my device even connect to the AP (Access Point) and stay connected reliably? There are several other considerations which would also come up, but let’s start with the real basic stuff and cover the more advanced later.
network stumbling is referred to the discovery of wireless network access points using a laptop or handheld device such as your smart phone.
RF surveying aka wireless site surveying is the term used for planning and installing a building wireless network or analyzing an existing network and ensuring that the wireless coverage, data rates, and network capacity satisfy the application requirements. The actual survey process would involve a site visit, possibly some building floor plans if there are obstructions to consider, as well as identifying RF interference in order to determine optimum installation locations for Wi-Fi access points.
Using your laptop or smart phone allows for mobility, so you can walk and survey the site. There are several FREE tools out there which can really help you when commissioning Wi-Fi devices. These tools will give you the basic Wi-Fi details such as SSIDs, signal strength, operating frequency band, channels, MAC addresses and encryption method/security status which is plenty of information to ensure connectivity of your device.
These tools use the built-in Wi-Fi adapter of your laptop or smart phone and give you live updates on several Wi-Fi network parameters.
My personal favorite free tool for Windows laptops is Vistumbler, even though it is not too fancy, it is easy to use, supports several nice features, and it is Open Source. Vistumbler uses the Windows native Wi-Fi API or netsh to find access points and get wireless information. It is a stumbling and surveying software tool which automatically scans for and logs access points, along with their signal strength, MAC address, channel, encryption method, etc. It supports GPS serial input for pinning AP locations, automatically shows them live in Google Earth and exports the access point GPS locations to a google earth kml file or GPX (GPS eXchange format) for near optimum site survey.
Another decent tool to use on your smart phone is WiFi Analyzer available as a free app.
There are several other free tools which are worth a try as well and may give you features lacking in Vistumbler:
Acrylic Wi-Fi Home – recognizes larger bandwidths, it can name the 802.11 standard (including ac)
HeatMapper – offers attractive colorful, graphical view of the airwaves around you and some security features
Homedale – simple and offers optional command line interface
LizardSystems – offers some nice analytics and reporting features
WirelessDiagnostics – for Apple users – MAC OS X Mountain Lion v10.8.4 and later
NetSpot – only tool for both Windows and MAC OS
For best results with these Wi-Fi analytic tools, disconnect your device from all access points while scanning for networks. If no access points show, make sure the right network adapter is selected in the Interface menu.
Some of these tools can be paid for or plug-in-enhanced from the community or on your own! This really opens up the door to a ton of possibilities. It is possible to uncover “hidden” (non-broadcasted) SSIDs, display noise levels in real time, display statistics on successful and/or failed packets on the network, and even password cracking tools useful for penetration testing purposes of your network – if a free tool can easily crack your password, then it is not much of a password.
There are computer guys who stumble and survey as a hobby – called warwalking or the more efficient wardriving, so make sure your network APs are secure by giving them nice, long and hard-to-crack passwords and always use the latest encryption methods (more on wireless security in part 2). In addition, you may want to check your Wi-Fi router’s firmware, research some of its known vulnerabilities, and upgrade it!
Having your network in the air certainly makes things interesting and there is a lot more to talk about. Feel free to leave your comments or questions below, and look for the more advanced Part2 of this thread coming soon!