Monitor radio parameters in real time using Wavemon, a text-based tool for Linux.
When using Linux, the Wireless Tools provide a wealth of status information. These tools get their information from the standard kernel interface /proc/net/wireless. While ideal for providing accuracy in measuring signal strength and noise data, these tools are not designed to give an indication of performance over time.
Wavemon (http://freshmeat.net/projects/wavemon) is a terrific little tool that does precisely this. It polls /proc/net/wireless many times each second to give you a rolling report of how your wireless connection is performing. Its simple curses interface keeps the code quite small and is ideal for including in embedded distributions (such as Pebble [Hack #70]) to get real-time link data from remote access points.
Ubuntu users can install the package with an apt-get install wavemon command. Contributed RPM packages appear to be available at http://rpm.pbone.net for distributions such as Fedora and RedHat. Alternatively, compiling from source is straightforward. Unpack the source code, and use standard compile commands:
./configure make make install
The main interface provides a nice graphical representation of the current link state, as shown in Figure 2-31.
All of the statistics are updated in real time, making it ideal for monitoring point-to-point links and fine-tuning antennas on long distance shots. For an even easier to read display, press F2 to bring up the Level Histogram shown in Figure 2-32.
Figure 2-31. Wavemon in action
Figure 2-32. Scrolling histogram
This display is easy to read on a laptop, even in bright sunshine, making it an ideal tool for outdoor work. The histogram sweeps to the left, giving you a history of the last few moments of wireless connectivity. Since Wavemon runs in a terminal, you can easily run more than one instance to monitor multiple radio links simultaneously.
When you need a high-performance signal and noise meter for Linux, Wavemon is hard to beat.
Bluetooth, Mobile Phones, and GPS
Network Discovery and Monitoring
Wireless Network Design
Appendix A. Wireless Standards
Appendix B. Wireless Hardware Guide