How to: Conduct a Wireless Site Survey

[wagnerk]

How to: Conduct a Wireless Site Survey

With wireless systems, it’s very difficult to predict the propagation of radio waves and detect the presence of interfering signals without the use of test equipment. Even if the system implements omni-directional antennas, radio waves don’t really travel the same distance in all directions. Instead walls, doors, elevator shafts, people, and other obstacles offer varying degrees of attenuation, causing the RF (radio frequency) radiation pattern to be irregular and unpredictable. As a result, it’s absolutely necessary to perform a wireless site survey to fully understand the behavior of radio waves within the operating environment before installing access points.

Site survey concepts

The ultimate goal of a wireless site survey is to determine the number and placement of access points (or mesh nodes) that provides adequate signal coverage throughout a facility or city area. With most implementations, “adequate coverage” means support of a minimum data rate or throughput. In order to perform a successful survey, you’ll need to relate the required performance to a value that survey tools measure, such as SNR. A wireless site survey also detects the presence of RF interference coming from other sources that could degrade the performance of the wireless LAN.

To read the whole tutorial, see here.

-ken