How to fix WIFI interference? Part 2

Are you observing interference with your WIFI network? Are you wondering what the source of the problem is: Unfortunate placement of access points, uneven traffic between the 2.4 GHz and 5 GHz bands, or other sources of radio frequency signals? How about other devices? Check.

See the first part of this post for information on signal-to-noise ratio.

Testing interference in your own WIFI network

This can be done in a variety of ways, each of which involves surveying areas of network coverage. Spot checks are carried out, actively monitoring interference levels with the appropriate apps and wireless adapters. It is best to use professional measurement software, such as AirMagnet or Ekahau, and then analyze the data. The results will create heat maps of signal, noise and SNR superimposed on floor plans of the coverage area.

When using professional measurement software, it is best to use both passive and active modes simultaneously. Passive mode captures signal and noise data of all access points or channels. This allows you to detect general signal and interference problems. Active mode connects the client to the WIFi access point and shows only the details of that connection, which helps, for example, to assess roaming.

Interference from proprietary access points

The key problem with network interference, is actually the networks themselves. Pay attention to whether the wireless network has been properly designed and configured, otherwise AP signals may interfere with each other. AP cells should have an overlap of 15% to 20%. If there is less or no overlap between AP cells, there may be areas of poor signal in the network. If there is too much overlap between AP cells in any band, it can cause cross-channel interference and other problems. The idea is to locate APs so that customers can go to the best AP for the location and so that they don’t interfere with each other’s signals.

Interference from other wireless devices. Spectrum analyzer

Most WIFI measurement tools and software only recognize signals from WIFI devices. However, obstructions in WIFI bands can come from other wireless devices, such as electronic nannies, security cameras, microwave ovens and radar. If you see interference or noise that you can’t identify with WIFI measurement equipment, try an RF spectrum analyzer. Tools such as the Chanalyzer from Wi – Spy DBx can provide a visual picture of the signal or noise, and help you detect the source. Some professional WIFI measurement software is also integrated with spectrum analyzers, so you can collect both WIFI and general RF data as you walk around the heat map.

Direct more customers to the 5 GHz band

The 2.4 GHz band can generate more interference and congestion. Using the 5 GHz band helps clients avoid interference, thereby increasing overall network performance. In addition to simply making sure access points and clients support both bands, consider using any band control feature provided by access points.

This feature can encourage or force dual-band devices to connect to the 5 GHz band of access points instead of leaving it up to the user or the client itself.

Beam shaping function to minimize interference

Check if your AP supports beamforming, and if it doesn’t, make sure to upgrade.

Dynamic beamforming focuses WIFI signals only where they are needed, while automatically “directing” them around emerging interference.

Such systems use different antenna patterns for each customer, changing them as problems arise. For example, when there is interference, a smart antenna can select a signal pattern with attenuation in the direction of the interference, thus increasing SNR and eliminating the need to lower the physical data rate.

Take care of speeding up your WIFI connection

Indirectly, increasing the transmission speed of WIFI can help minimize interference. The faster communications are sent and received, the less interference can affect them.