Network Signal Test GSM Guardian Locations

GSM Signal Testing for GSM Guardian projects


Rainforest Connection GSM Guardians require cell phone connectivity to stream the audio they require.

Therefore, we must make sure every single site where we plan to install a Guardian must have GSM signal test before the Guardians even enter the project country.

It is RFCx’s responsibility to communicate to the partner that they need to check the GSM connectivity of each site they plan to install the Guardians.

This document will demonstrate how to check for GSM connectivity.

Step 1 - Download App ‘Network Cell Info Lite & WIFI’ 

Download the app from the play store for Android. iPhone have a separate app called LTE Cell Info: Network Status 4.

Figure 1. This application has the capability to measure the GSM cell signal strength and give a reading in dBm.

Step 2 - Change Mobile Network connections to 3G only

In order to replicate the connections conditions of the Guardian you need to change your phones mobile network settings to 3G only. This is because the Guardian isn't capable of connecting to 4G / LTE. If you do not change your mobile network settings to 3G only, you will not be replicating the Guardian connection conditions

Figure 1. Settings on an Android phone to access mobile networks

Figure 2. Setting your phone to only access 3G networks, to replicate the Guardian.

Step 3 - Checking Signal Strength 

You will open the app on the ‘Gauge’ tab. This tab will display the GSM cell signal strength. You will see a semi circle measure from -50 (best possible signal) to -120 (no signal at all). Good and bad is also indicated by colour grading from green (good/best) to red (bad/worst).

Figure 3. Example of bad signal

Figure 4. Example of good signal

Figures 3 and 4 provide examples of good and bad signals. You would not install the GSM Guardian under figure 2 measurements.

Figure 3 indicates a dBm level of -87, for the Guardians we want minimum levels of -97, anything lower would seriously jeopardize the Guardians ability to stream audio.

In both figures 3 and 4, you will see ‘LTE virgin’ and ‘EDGE Virgin’. Virgin is the Carrier/provider which is in ‘my’ (the creator of this document’s) phone. Your phone will say something else, like Claro, Vodafone etc. Depending on what company provides your cell service. If you are in an area where your provider does not provide service, the check will show no signal/service. You will need to ensure the sim in your phone is the same sim card carrier provider as is in the Guardian. I.e. if Claro works in the area where we want to install the Guardian, then in order to accurately check if the Guardian works, your phone will need a Claro sim, just as the Guardian will have.

NB. The partner will most likely be checking the signal strength at the bottom of the tree, this is important because when we climb the tree to install the GSM guardian the signal will almost certainly be better.

Step 4 - Checking upload speeds 

Next we should check the upload speeds by the Guardian Install locations. We can do this by switching to the ‘Speed’ tab and starting the test (figure 5.).

Figure 5. Starting the upload test (press the start button)

Figure 6. The upload speed test in operation

Figure 7. The upload speed test finished (with results)

You will not experience upload speeds from figures 6 and 7 in the field. However, the Guardian can stream audio with successfully with xx Kb/s[a]

Step 5 - Recording the information

It is imperative that the partner record the data in a table format (table 1.) below. This will allow RFCx to access each site's suitability for a GSM Guardian Install.

Guardian Site Signal Strength (- dBm)  Upload Speeds (Kb/s) Coordinates Site 1
Site 1
Site 2
Site 3
Site 4
Site 5


Skipping this process risks jeopardizing the success of the GSM Guardian project.