Video Transcript:

Hello and welcome to this video where we will show the result of a wireless experiment using the Kvaser Air Bridge Light HS.

The purpose of the experiment is to illustrate the significant reduction in signal strength that happens when you obstruct the line of sight of the two Air Bridge units. We will do this with the help of a metal cage called a Faraday cage.

The metal cage is covered with a copper mesh net, which hinders wireless signals getting through. Inside the cage is a spectrum analyzer that measures signal strengths at different frequencies. The experiment consists of two different scenarios.

In the first case, both Air Bridge units are inside the metal cage.

And in the second case, one of the units is placed outside of the cage. In this case the copper mesh net acts as a barrier between two units.

In both the cases, signal strength between two units are measured with the Spectrum Analyzer.

If we begin to look at the spectrum for the first case, you can see that it contains the frequency range that the Air Bridge operates in, that is 2.4 – 2.48 GHz. The reason why there are several clear peaks is because of the Air Bridge’s own developed protocol. In the first case, when both units are inside the cage, the highest amplitude is -35.6 dBm.

If we now look at the spectrum for the second case, you can see that it contains the same frequency range as in the first case. The reason that the peaks are not in the same place and that there are only two is also because of the Air Bridge’s own developed protocol. When one of the Air Bridge units is outside the cage, the highest amplitude is -40.5 dBm.

We will now look at how to interpret these results…

In this experiment, there is a reduction in the signal strength by 4.9 dBm when the copper mesh net obstructs the line of sight. That reduction in signal strength will reduce the wireless connection range. How much is hard to say since there are several factors that affects the wireless connection range.

To get the most out of your Kvaser Air Bridge Light HS, you’ll want to have clear and unobstructed line of sight in between the two units as much as possible.

The units are sturdy, they are protected by a rugged aluminium housing. Therefore, they do not need to be encapsulated when you install them.

Thank you for watching this video.

Remember, radio is susceptible to interference. We recommend that you have fail-safe systems in place in safety critical environments.

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