Simulation & Wall
Wi-Fi simulations basically offer many advantages over APoS measurements. A simulation offers a higher flexibility, changes are possible and the effort on site is lower.
Especially for small objects Wi-Fi simulations are a great solution to save costs. Which customer wants to fly an engineer from Germany for a 3 hour job for a small site in the USA?
Here the cost-benefit ratio is out of proportion.
Therefore, a simulation offers a very good possibility to carry out an optimal planning.
However, as with everything, it’s “garbage in garbage out”!
Today’s WLAN tools offer a large selection of different walls. But where does the data come from and is it accurate for my property?
Does a drywall in the USA have the same attenuation as a drywall in Europe?
These are all questions we have to ask and answer for an optimal result. Therefore, there is often no way around a wall measurement.
For a corresponding measurement, however, someone must again be active on site. This does not necessarily have to be the experienced engineer. Actually, an employee on site is also sufficient.
The measurement is very simple and almost everybody has what he needs for it:
- Two end devices with WLAN
This can be an access point and a smartphone or two smartphone. The important thing is that one device “sends” Wi-Fi and the other “searches” for it.
Thus, a wide variety of tools are often used.
On the Mac, for example, there is the Wi-Fi Explorer or simply the status bar. iPhone or iPad can only use the Airport App from Apple. On Android and Windows, there are a high number of tools, e.g. WinFi.
However, these are all tools whose function is to display data about the WLAN. And there the tools show a lot of data.
This screenshot is from a Mac Mini that is not moving. Nevertheless, we can see a certain swaying. This can also not be prevented. However, we should not simply use “the value”. This RSSI value fluctuates, on the screenshot from -51dBm to -54 dBm, excluding the short-term -67.
When determining the attenuation of a wall, measurements are taken from both sides. For a 3 dB wall, the difference on both sides must be 3 dB accordingly.
On one side the value might be -60 dBm, on the other side it should be -63dBm. If now the 3-4 dB fluctuation of the Mac Mini, on the above example, is included, -57 dBm could be measured on one side and -66 dBm on the other side. Already a 3dB wall becomes a 9 dB wall. This falsifies the result massively.
Is a little more experience needed on site after all?
Wi-Fi Wall Measurement - The App
The answer is “not mandatory”. Personally, we have always been annoyed by this topic, because you are also on site and think about which value is now “the right one”. But you still don’t really calculate and qualify this.
Therefore, we have commissioned a developer for a very simple Android app, our “Wi-Fi wall measurement” app.
This is probably the simplest app. At the same time, it is also very efficient. Any customer can download this app on an Android smartphone or tablet and measure the attenuation of the wall.
We measure on the first side and then go to the other side. Press one button each time and wait 10 seconds. Already we have the result.
During these 10 seconds, several measurements are made to the connected access point and an average value is output.
International customers use their own device. Within Germany, we also like to send a device with associated access point around. The case consists of the following content:
- Aruba Wall Access Point – we still had lying around and is designed for wall mounting. So the case can be opened easily.
- AccelTex Accelerator – a very good battery with PoE output that we use regularly and therefore also have available.
- Adhesive pad – attaching the smartphone to the wall. This prevents unnecessary movement or a person standing between the access point and the smartphone.
- Documentation – How to use the app (1 page) and where to place the case for measurement.
Especially the location of the case / access point is important for the measurement. We lose considerable signal strength in the first few meters due to the FSPL (Free Space Path Loss).
Therefore, the access point should be at least 4-5 meters away from the smartphone.
For us, the app offers good added value in weekly use. Together with our customers, we can save a lot of effort, improve the quality of the results, and still offer attractive prices.
The conclusion of the customers is consistently positive, as the app is very simple and shipping in the PeliCase is also a safe and efficient option.
We have more features that we would like to include. Feel free to test the app and give us your feedback.