Introduction to NetSurveyor 802.11 Network Discovery Tool

NetSurveyor is an 802.11 (Wi-Fi) network discovery tool and, as such, its goal in life is to gather information about nearby wireless access points in real time and display it in a useful way. The data is displayed using a variety of different diagnostic views and charts. Data can be recorded for extended periods and played-back at a later date/time. Also, reports can be generated in Adobe PDF format. Applications for NetSurveyor include the following:

During the installation of a wireless network, as an aid in verifying the network is properly configured and antennas are positioned at locations to achieve efficient transmission / reception -- that is, for use in verifying Wi-Fi coverage and maximizing beacon signal strength
Trouble-shooting an existing network or wireless environment that is performing poorly
Reporting the presence of Wi-Fi networks and local access points and the signal strengths of their beacons
Conducting wireless site surveys where the installer is interested in learning about the coverage of a new or existing access point, roaming capability, presence of RF interference or “dead spots”, and optimum location of access points, their antennas and client stations
In a secure business environment, for use in detecting the presence of rogue access points
As a learning tool to help understand the relationship between access points (BSSIDs), wireless networks (SSIDs), and client stations (STAs)

NetSurveyor is distributed freely by Nuts About Nets LLC both as a convenience to network engineers, IT administrators, wireless technicians and WiFi users and, also, as a way of drawing attention to and generating interest in our other diagnostic products and RF analyzers. NetSurveyor can be downloaded from www.NutsAboutNets.com and www.PerformanceWifi.net. You may also distribute NetSurveyor as long as that is done without charge and you agree to the terms of the License Agreement.

NetSurveyor is a diagnostic tool that falls under the category of WiFi Scanners or 802.11 Network Discovery Tools. The best known in this category is NetStumbler (www.NetStumbler.com). A discovery tool reports the Service Set Identifier (SSID) for each access point (AP) it detects, along with the channel used by the AP. The way this works is that roughly every 100 mSec an AP sends an “I’m here” beacon – and the discovery tool (running on your laptop and using its 802.11 wireless adapter, also known as a station or STA) picks-up that beacon and adds the SSID to its list of known access points. In addition, the discovery tool reports the RSSI (Received Signal Strength Indication) for each AP, which is roughly an indication of how close the AP is to your current location (i.e. how close it is to the client STA). Just to be clear, the RSSI reflects the strength of the beacon as received by the STA – it is not an indication of performance.

We know there are other choices and discovery tools available – so, we appreciate your interest in NetSurveyor and the time you’ve taken to check it out. And we’re sure you won’t be disappointed. NetSurveyor distinguishes itself from other tools in its category in the following ways:

It’s free.
In addition to the grid that repeatedly updates information about each access point, there are 6 graphical, diagnostic views (discussed elsewhere in this document): (1) Timecourse of Beacon Qualities For Each Access Point, (2) Differential Display of Beacon Qualities for Each Access Point , (3) Usage of Each of the 802.11 b/g Channels, (4) Timecourse of the Usage of Each of the 802.11 b/g Channels, (5) Heatmap / Waterfall Chart of the 802.11 b/g Channels and (6) Channel Spectrogram of the 802.11 b/g Channels. The more (and different) ways you have at looking at the data then the greater the chance will be that something will catch your eye that you might otherwise miss if only a single type of chart were used.
Generates reports in Adobe PDF format that include the list of access points and their properties along with images of each of the 6 diagnostic charts.
Powerful and innovative logging and recording capability. Other products, if they even offer a recording/playback feature, usually follow the “tape recorder” paradigm. NetSurveyor is integrated with NetPlayer (an application we use for displaying recorded data files). NetPlayer is unique in that it shows you all the recorded data – that is, you do not press a ‘play’ button and then forced to watch minutes or hours of data scroll by in the hope that some unusual event will catch your eye. NetPlayer’s unique approach makes reviewing recorded data a snap.
If your laptop or PC has multiple wireless adapters installed – not a problem. When NetSurveyor launches it detects each of these and asks you to choose which one to use for that session.
Supports most all wireless adapters – that is, those that are installed with an NDIS 5.x driver (or later). This would include wireless adapters running on Windows 2000, XP and Vista.
Can be run in ‘Demo’ mode – so, even if you don’t have a wireless adapter attached to your desktop or laptop machine you can still experiment with the application to see whether it suits your needs.

Below are sample screenshots taken of the various diagnostic views. Each of these are discussed in greater detail elsewhere in this document.

1. Timecourse of Beacon Qualities for each access point (AP).

2. Differential display of Beacon Qualities for each access point (AP).

3. Usage of each of the 802.11 b/g channels.

4. Timecourse of the usage of each of the 802.11 b/g channels.

5. Heatmap / waterfall chart of the 802.11 b/g channels.

6. Channel Spectrogram chart of the 802.11 b/g channels.