In addition to connecting computers to the Internet, professional users are increasingly using wireless local area networks (WLAN) for business-critical applications. Examples include accessing of patient files, online monitoring of production facilities, and the transmission of video and audio data (ideally without any time lags). The reliability and performance of WLAN systems are thus increasingly important.
The rising significance and usage of WLAN for data transmission is resulting in more and more scenarios where the equipment and systems of various users are crowding the WLAN frequency ranges. These may include, for example, microwave ovens, cordless telephones, Bluetooth devices and video transmitters, with their signals occurring on a continual or intermittent basis. The simultaneous usage of a frequency band or frequency range gives rise to interference that can disrupt or negatively impact the reliability and performance of a WLAN. This type of interference can result in data packets or connections being lost. If the interference is too strong, the complete failure of the WLAN may result.
It is therefore becoming increasingly important to use targeted analysis to check the frequency ranges. These checks should identify the interference or other interference factors, and introduce countermeasures as required. It can also be used to ensure that the WLAN is working properly and operating interference free.
Targeted analysis can also clarify or identify the following:
- Proper, fault-free operation of the WLAN
- Existence of interference or noise
- Display or identify the bands with interference
- Strength of the interference signal
- Regularity or frequency of the interference signal
- Type, and possibly source, of the interference signal
The WLAN-related frequency ranges are subject to spectral analysis. Results are displayed graphically, i.e. in the form of real-time diagrams or real-time overviews of frequencies and interference. However, graphical analyses of a spectral range are open to some freedom of interpretation. Therefore, the following scenario should be fairly commonplace: You ascertain that the frequency currently being used is being subjected to interference that is continual and of constant signal strength. However, you cannot unequivocally ascertain or even "read-out" which room or building the signal is coming from, nor the type of equipment which is transmitting the interfering signal.
