Hi everyone,
I hope you can help me.
As of today, my FP4 has an icon as if the device is making a Wi-Fi call with arrows (receive and transmit) flashing.
This probably consumes data because mobile networks are constantly cutting out.
I tried rebooting, updating the device but no change. Any idea?
Wifi calling never consumes mobile data. It is accounted as a local call (i.e. call from your SIM’s home country).
Mine uses Wi-Fi Data when out of my homes internets range. It keeps the connection stable in the US to avoid dropped calls. If you do have a pre-paid plan like I do where you get a set amount of data like 5GB like most Carriers in the US charge for. And your using a lot of data. You might have to switch to a unlimited plan for your company to charge you for the amount of data you use each month. It will cost more for more data you use. This is a scummy business practice when in the EU. There is no data caps for Wi-Fi usage. Its just another way to nickel and dime you out of your hard earned money. They even like throttling your speeds from the advertised speeds here in the US because our consumer protection laws plus the removal of net neutrality in my area are basically non existent. Unless things change everywhere in the world except the EU in terms of the internet. We are most likely going to continue to have these issues.
However. If you set your sim in settings for Wi-Fi Calling to only use when connected to a Wi-Fi connection and not use mobile Data. That should solve your issue in regards it wasting all of your airtime data. Hope this info is useful for you.
Once again. Calling never consumes your mobile data. Not with 2G calls, not with 4G calls, not with VoLTE, not with VoWiFi. Never. Period.
Welcome to the forum.
The 
symbol represents 4G Calling, not Wi-Fi Calling, whose symbol is similar but completely round (no 90° angle top right).
Not sure what you mean. You don’t show the complete status bar so we don’t know whether you’re connected to Wi-Fi as well, nor the quality of the cellular connection, but “5G” would normally mean that your cellular / mobile data connection is OK.
I disagree. Mobile data is used. I have mine set to use all gens up to 5G. And it clearly uses wifi to connect to T-Mobile. Its a setting in settings period. Here is definitive proof that he has it set wrong in settings. Please get your facts straight before saying otherwise thanks.
Mobile Network is not mobile data. And as long as Wifi Calling is used def. no mobile data for calls are used.
Edit the settings just show under which condition Wifi Calling is used. Always when wifi is connected, only when no mobile network
Wi-Fi Calling means using “Voice over IP”, through the Wi-Fi WLAN connection. It’s useful if the normal cellular connection is weak or absent - for example if you’re in the country far from a mast but you have a cabled Internet connection.
If you disable Wi-Fi Calling, you can only be called over the standard cellular mobile network (voice calls), which may offer VoLTE or “4G Calling”, but these do not use what you think of and pay for, as “mobile data”, with so many GB per month, that allows you to use your phone as a computer connected to the Internet.
If you enable Wi-Fi Calling, then you can choose how that is implemented:
None of these options has anything to do with mobile data.
@OldRoutard got it right. Please correct your facts before asking others to correct their facts 
I’ll just add the last technical bit that might confuse some people.
When the 4G/5G SIM card connects to the mobile network, it creates several “tunnels” via which it can communicate with the network. These “tunnels” are named, and their name is called APN. For most providers, mobile internet is routed through the APN called simply “internet”. And this is the “data” you pay for. This is the GB/month limit on your monthly invoice.
If you have VoLTE/4G Calling enabled, a second “tunnel” is created, this time named “ims” (standing for IP Multimedia Subsystem). This is where voice and video calls via the provider (not Skype/Messenger/etc) are routed through. Of course, your phone is still sending IP packets to the mobile network (which can be seen as data), but the “ims” APN is accounted not data-wise but minute-wise - the same way as if you make a normal call. This is the minutes/month limit for calls on your monthly invoice. The fact that IMS packets are accounted minute-wise is just a decision of the mobile providers, but all of them (AFAIK) agree on this.
When you set up Wifi calling, it just means your phone does not necessarily need to use the mobile network to connect to the other end the the “ims” “tunnel”, but it may find a different way via the wifi connection. But it still connects to the “ims” tunnel. So also all calls made via wifi calling are accounted as called minutes (and not as data). Of course, somebody has to pay for the internet on the wifi, but that’s a different story, and most wifis are connected to a data-unlimited internet connection It is important to see the difference here in the sense that your phone sends packets to the “ims” “tunnel”, so it accounts called minutes, but the wifi router on the way does not look into the packets and so it cannot know that they are “ims” packets. So the wifi router sees them as generic data and also accounts them so.
Theoretically, if you e.g. contract a private 5G Network, you can open multiple other “tunnels” from your SIM card, each with a little bit different behavior (QoS, accounting, bandwidth limits etc). It is then on the agreement between you and the private 5G provider how is each of these “tunnels” accounted. I can imagine you could e.g. get one tunnel for IoT devices sending a few bytes per day - this would be accounted with a fixed monthly payment and it would have strict limits on consumed amount of data. And then you could have some “tunnel” with higher throughput (e.g. for distributing updates), which would be accounted per transmitted MB. Technically, this wouldn’t be that simple, because currently there aren’t any off-the-shelf 5G modems that would be able to connect to more than the two APNs “internet” and “ims”. But it seems their time is almost coming
Please stop deleting posts, just beause there is different opinion, deletin posts destroys the conversation. No need to emphasize you were not lying and wanted to help. We all know that your intention is always good and we all make errors from time to time.
Please, do not feel insulted. I did not mean it like that. I only wanted to correct some of your statements so that later readers do not make wrong conclusions.
If you have problems with something eating your data, search for “app data usage” in settings and find the rogue app.
I didn’t think I would start such a strong debate, sorry…
However, thank you for your various responses.
I don’t understand everything, but from your point of view, is it normal to have this signal which represents 4G calling (thanks Oldroutard) permanently on on an FP4, with the up and down arrows flashing?
If the device is constantly accessing the 4G calling in the background, this may have an impact on the data (or not, I didn’t understand everything), and on the battery life.
Thanks.
Yes.
It just means that
A) the 4G function has been enabled by the user;
B) it is actively provided by the network operator for that phone and is therefore operational.
The same applies to the “Wi-Fi Calling” signal 
which signifies that
A) the function has been enabled by the user;
B) it is actively provided by the network operator, the phone has a viable Wi-Fi connection and a data link has been successfully established over the Internet so that the function is operational.
N.B. - not all subscribers are eligible for Wi-Fi Calling. It’s only available if the phone is compatible, and the operator recognizes the phone, and provides the service.
The up/down arrows usually just indicate network activity, whether mobile data or Wi-Fi. When the phone has a viable Internet connection there will constantly be some traffic, however minimal, so these will be shown much of the time. Some versions of Fairphone OS don’t show them at all as some users find them distracting.
As stated above, the 4G Calling icon just shows that the service is available.
As explained by peci1, 4G Calling does not use “mobile data” as counted by your operator in GB (so no impact on mobile data consumption).
Having 4G Calling active may slightly increase power consumption but I think not much.
Having Wi-Fi connected, and / or mobile data, does increase power consumption.
Okay, many thanks for all this useful informations.
