Can't do Wifi calling. AT&T. Apple Watch 3 LTE

[ZipZap]

I too also thought the watch made the call using wifi through my iPhone, but I always put the phone in Airplane mode. Even calls made Via cellular on the watch, with iPhone in airplane mode, show up on my t-mobile account as being made by the iPhone. I think its really just how T-mobile masks the numbers using Digits, because even calls made from the watch will show up as my iPhone on caller ID.

I turned off my phone. Watch indicated it was on WIFI. Made a call.

That should be a WIFI Call, right?
[doublepost=1507988518][/doublepost]

Update 10/13 5:59PM PDT: At about 4PM I received another call from a senior advisor, they wanted yet more screenshots of some settings. Im not sure if the previous advisor I spoke to earlier today made a mistake or what happened. Anyway, this particular advisor told me that she personally knew the engineer and she spent a good 30-40 minutes testing out various scenarios with me. These involved turning the phone off and making sure watch was on WIFI while she attempted to call me. Not to my surprise I never did receive a call on the watch, but the advisor told me that on her end the phone never rang and it never went to voice mail, it was just dead silent.

She then had me turn the phone off and attempt to make an outbound wifi call from the watch, and as we all know, all calls failed. I appreciated her willingness to try some things our. I think now she had a better understanding of whats going on.

She then proceeded to get screen shots of WiFi calling enabled setting on phone, calling on other devices, iCloud account, faceTim settings, and 2 wifi network settings. She also go a screen shot of the Watch.app phone settings, where the Wifi Calling toggle is. She was surprised it was not showing up and I explained that it will only show up if I remove the cell plan from the watch. She thought that was very peculiar and wrote that down too. I also mentioned that I knew at least 2 people on ATT that are also having the issue, but im not sure if she made a note of it.

She also tried to contact the engineer working on the case so she could get live feedback from them, but was unable to make contact. So she wrote a report and sent it back to engineering. I have a callback scheduled for Monday 2PM PDT.


Update 10:26pm PDT: I removed the cellular plan from my watch again, and as we already knew, in the watch.app phone setting WiFi calling toggle now appeared. So I decided to put my phone in airplane mode and made sure watch was connected to WiFi. I then placed 2 successful WiFi calls that correctly showed up on caller ID as my normal phone number. Things are very strange here.

Update 11:45PM PDT: I re-activated the cellular plan on the phone, and of course now lost the ability to make wifi calls. Tests where done by putting iPhone into airplane modre and turning off cellular on the watch. Watch switched to wifi, all calls failed, nothing new here.
After re-enabling the Cellular toggle on the watch I went into the settings->General->About on the watch. Then I noticed that there was a field titled "Network" at this time it read T-Mobile WiFi. I thought that was interesting, watch was connected to WiFi and the cellular toggle was on. So the watch was correctly recognizing the network as T-Mobile Wifi. So I placed some calls and they went through no problem and I have to wait to see what T-mobile logs them as.

What is peculiar is that i've done this before, i've made calls that seem to be WiFi Calls but are logged as regular cell calls. So i'm interested to see what t-mobile logs these calls as. I have a attached a screenshot below. Another interesting thing is if I turn off the cellular toggle off but still connected to Wifi, the network field reads "Not Available" which reinforces the idea that the eSIM has to be powered on for the watch to connect to T-Mobile for Wifi calling. It will also read "Not Available" when watch is connected to phone by bluetooth. The part that doesn't make sense is why calls are logged as cellular calls. Will update when T-Mobile shows my calls and how they are logged.

Two things:

1) Airplane mode is not enough has there have been reports that the phone does not fully turn of WIFI. Turn off your phone.

2) Have you considered the deactivating and re-activating ATT may cause you to lose the credits later?

 

[sirozha]

I turned off my phone. Watch indicated it was on WIFI. Made a call.

That should be a WIFI Call, right?
[doublepost=1507988518][/doublepost]

Two things:

1) Airplane mode is not enough has there have been reports that the phone does not fully turn of WIFI. Turn off your phone.

2) Have you considered the deactivating and re-activating ATT may cause you to lose the credits later?

Airplane mode turns off any wireless communication. It’s the Wi-Fi and Bluetooth toggles in the iOS’s 11 Control center that do not completely turn off their respective wireless signal.

 

[Smoothie]

After the activation of the LTE plan on the Watch, turn off the iPhone, then reboot the watch, and as it’s rebooting: turn the iPhone back on. The iPhone will come up before the Watch. Once both devices power back on, put the iPhone in airplane mode, wait a minute or two, and test calling from/to your watch. It should work just fine, and in my case it rings together with my Mac, and I can answer the phone call on either device. It certainly behaves as though it were using Wi-Fi Calling in this scenario, but I can’t vouch it is not using its cellular signal.

I've only had my LTE (Verizon) watch for three days, so I'm no expert. But I thought that the watch can only use the cellular network if the phone is connected to the cellular network at the same time. (The phone doesn't need to be in range of the watch.) So if your phone is in airplane mode, the watch must be connecting via WiFi.

 

[dave006]

I never said it appeared on this screen. It appears on a different screen under Settings > Phone > Calls on Other Devices but only when you make the other watch active. It’s obviously a bug that is either cosmetic or it’s a bug that reveals that under the hood there is a toggle for Wi-Fi Calling that Apple initially wanted to expose to the users but later decided to hide.

No the issue is that the Toggle is not shown if the active Watch has a Carrier plan. We have proven the behavior by removing the Carrier plan, the Wi-Fi calling option appears. Re-add the Carrier Plan and the Toggle is gone.

Another point is that the assertion that an iOS device must have a SIM to be able to use Wi-Fi Calling is wrong. I have a cellular iPad Air that has no SIM in it (I took it out), and I was just able to activate “Wi-Fi Calling” on it in the FaceTime settings without any issue whatsoever. It worked exactly like it does on the Mac when you activate Wi-Fi Calling in the FaceTime preferences.

You might want to go back and re-read my post. I suggested: remove the SIM from your iPhone and try to make a Wi-Fi call. It will not work! Sorry, your test on a Cellular iPad is a nice random data point but is not relevant to this discussion.

The Cellular iPad is a "Data" only device from the Carrier provisioning standpoint, It does not have Voice / Talk enabled for Cellular calls. Your test using FaceTime Wi-Fi calling is actually exactly how it should perform as documented by Apple, so no issue or positive indication of anything relating to the LTE Watch.

eSIM does not to be powered for a device with cellular capability to make Wi-Fi calls. That assumption is wrong,and I just disproved it by enabling Wi-Fi calling on a cellular iPad with SIM taken out.

Again, you have proven nothing yet about how devices like the LTE Watch and the iPhone with Voice/Data SIM(s) from the Carrier perform Wi-Fi Calling. Let us know how your iPhone works when you remove the SIM Card and try to make a Wi-Fi call.

Please keep us posted as we all want the LTE Watch to perform correctly and use direct Wi-Fi calling from the Carrier before failing over to LTE to save the battery.

Dave

 

[deadworlds]

I turned off my phone. Watch indicated it was on WIFI. Made a call.

That should be a WIFI Call, right?
[doublepost=1507988518][/doublepost]

Two things:

1) Airplane mode is not enough has there have been reports that the phone does not fully turn of WIFI. Turn off your phone.

2) Have you considered the deactivating and re-activating ATT may cause you to lose the credits later?

1) Airplane mode turns off all of the radios, want to check? Put the phone in airplane mode, now to go the settings, Wifi, bluetooth and Cellular all say "OFF" on them. Another way to check is try using the internet, which will fail. Try making a call, will also fail. Try using the watch app to look at the About section, the app will tell you the watch is not connected.

2) No im not worried about loosing my credits because I am not cancelling the line with T-mobile. I am simply removing the plan from the watch, and then adding it back on. Also when I add the plan back onto the watch, the T-mobile portal says "we found a plan on your account that was previously associated with this watch, would you like to add this to the watch, or created a new one?" Clearly I select to add it, not create a new one.
[doublepost=1508000405][/doublepost]

I never said it appeared on this screen. It appears on a different screen under Settings > Phone > Calls on Other Devices but only when you make the other watch active. It’s obviously a bug that is either cosmetic or it’s a bug that reveals that under the hood there is a toggle for Wi-Fi Calling that Apple initially wanted to expose to the users but later decided to hide.

Another point is that the assertion that an iOS device must have a SIM to be able to use Wi-Fi Calling is wrong. I have a cellular iPad Air that has no SIM in it (I took it out), and I was just able to activate “Wi-Fi Calling” on it in the FaceTime settings without any issue whatsoever. It worked exactly like it does on the Mac when you activate Wi-Fi Calling in the FaceTime preferences.
[doublepost=1507980560][/doublepost]
T-Mobile provides no call detail for the fake phone number they assign to the LTE Apple Watch. They only provide the total number of minutes for calls from/to that number. All the call detail is listed under the iPhone number with which the LTE Watch number is pared via DIGITs.
[doublepost=1507980960][/doublepost]

eSIM does not to be powered for a device with cellular capability to make Wi-Fi calls. That assumption is wrong,and I just disproved it by enabling Fi-Fi cCalling on a cellular iPad with SIM taken out.
[doublepost=1507981533][/doublepost]
I’m not having any problems with the watch making or receiving calls while the phone is in Airplane mode and I am on my home Wi-Fi. The only uncertainty for me is if in this scenario the LTE Watch is using my home Wi-Fi or it’s cellular connection. It’s an important thing to figure out and have Apple fix it if in fact the LTE Watch uses its LTE signal for making and receiving calls in this scenario. However, this is a very marginal use case, and at the end of the day what really matters is if the LTE Watch can function as a phone in this scenario, which for me it can.

After the activation of the LTE plan on the Watch, turn off the iPhone, then reboot the watch, and as it’s rebooting: turn the iPhone back on. The iPhone will come up before the Watch. Once both devices power back on, put the iPhone in airplane mode, wait a minute or two, and test calling from/to your watch. It should work just fine, and in my case it rings together with my Mac, and I can answer the phone call on either device. It certainly behaves as though it were using Wi-Fi Calling in this scenario, but I can’t vouch it is not using its cellular signal.

You provide a lot of anecdotal evidence that does too apply to this situation or the apple watch. Also how do you explain the fact that my watch (under the about section) will display No network when the eSIM is disabled, yet will display "T-Mobile Wi-Fi" when the eSIM is enabled and connected to wifi?

You should let the people who are actually testing these things out and are actively trying to come up with some understanding of how the watch works, be the ones to make these statements and post here. You have literally provided nothing useful or beneficial to this thread.

 

[Smoothie]

I'm able to make calls over WiFi on my LTE watch when my phone is in airplane mode. But I'm unable to receive calls on the watch over WiFi in the same situation. All calls go to voicemail. Any ideas about this?

 

[deadworlds]

I'm able to make calls over WiFi on my LTE watch when my phone is in airplane mode. But I'm unable to receive calls on the watch over WiFi in the same situation. All calls go to voicemail. Any ideas about this?

Welcome to the club.

 

[Smoothie]

Welcome to the club.

It cost me $650 to join the club and there doesn’t seem to be much exclusivity.

 

[dave006]

I'm able to make calls over WiFi on my LTE watch when my phone is in airplane mode. But I'm unable to receive calls on the watch over WiFi in the same situation. All calls go to voicemail. Any ideas about this?

As @deadworlds, indicated this is part of the problem we are trying to get Apple Engineering to look into. Do you have detailed billing with your Carrier so you can verify that your Watch is not actually making these outgoing calls over LTE. I found my Watch doing it even when connected to Wi-Fi by checking my detailed calling history for my Watch's phone number.

The issue with incoming calls going directly to Voicemail is also exactly what we have seen. This indicates that the Watch is not actually active on the Carriers network via Wi-Fi Calling. However if the Watch has LTE enabled yet shows a Wi-Fi connection, it will actually receive incoming calls over Cellular.

Dave

 

[Smoothie]

As @deadworlds, indicated this is part of the problem we are trying to get Apple Engineering to look into. Do you have detailed billing with your Carrier so you can verify that your Watch is not actually making these outgoing calls over LTE. I found my Watch doing it even when connected to Wi-Fi by checking my detailed calling history for my Watch's phone number.

The issue with incoming calls going directly to Voicemail is also exactly what we have seen. This indicates that the Watch is not actually active on the Carriers network via Wi-Fi Calling. However if the Watch has LTE enabled yet shows a Wi-Fi connection, it will actually receive incoming calls over Cellular.

Dave

I just signed up for cellular service on my watch yesterday, and I haven't looked at a detailed Verizon bill in years. I assumed that Verizon doesn't include specific phone calls on the bill anymore since it's unlimited calling. I'll have to check. Before signing up for LTE service on the watch, I could make what I thought were calls over WiFi with the phone in airplane mode, but I couldn't receive any calls on the watch. This is exactly the same behavior since I put the watch on the cellular plan. With the watch connected to WiFi and with LTE enabled, the watch doesn't receive phone calls even if the phone is in airplane mode or off.

This seems to be a problem on Apple's end since this problem exists on more than one carrier.
[doublepost=1508014287][/doublepost]I just checked my Verizon usage online. It does list individual calls. It shows outgoing calls from the watch on my iPhone number while I was testing WiFi calling on the watch before I signed up for an LTE plan. It also shows outgoing calls on the new watch number after I set up LTE when I was away from the house with Bluetooth off on the iPhone. I set up the watch plan yesterday and I haven't had a chance to test incoming calls to the watch over LTE. I'll try that later when I'm out of the house.

I just made a call from the watch while it was connected to my home WiFi with the phone in airplane mode. Nothing showed up on the bill for either the watch number or the phone number. It's possible that the records don't update quickly. I'll check again later.

 

[dave006]

Your last sentence is different from my experience. When you try calling your iPhone while it is in Airplane mode, and your Watch is on Wi-Fi but with LTE enabled and in a location where a Cellular signal is available. Your Watch should receive the inbound call.

Have you tried stepping outside to get an active LTE signal on your Watch and have someone call your iPhone while it is still in Airplane mode? Your Watch should ring and receive the Cellular call if NumberShare is properly setup on Verizon.

Note: Have you updated your Watch to 4.0.1 since you just got it yesterday.

Dave

 

[deadworlds]

I just signed up for cellular service on my watch yesterday, and I haven't looked at a detailed Verizon bill in years. I assumed that Verizon doesn't include specific phone calls on the bill anymore since it's unlimited calling. I'll have to check. Before signing up for LTE service on the watch, I could make what I thought were calls over WiFi with the phone in airplane mode, but I couldn't receive any calls on the watch. This is exactly the same behavior since I put the watch on the cellular plan. With the watch connected to WiFi and with LTE enabled, the watch doesn't receive phone calls even if the phone is in airplane mode or off.

This seems to be a problem on Apple's end since this problem exists on more than one carrier.
[doublepost=1508014287][/doublepost]I just checked my Verizon usage online. It does list individual calls. It shows outgoing calls from the watch on my iPhone number while I was testing WiFi calling on the watch before I signed up for an LTE plan. It also shows outgoing calls on the new watch number after I set up LTE when I was away from the house with Bluetooth off on the iPhone. I set up the watch plan yesterday and I haven't had a chance to test incoming calls to the watch over LTE. I'll try that later when I'm out of the house.

I just made a call from the watch while it was connected to my home WiFi with the phone in airplane mode. Nothing showed up on the bill for either the watch number or the phone number. It's possible that the records don't update quickly. I'll check again later.

For T-mobile, calls take about 30mins to 1hr to show on the call logs. For ATT I believe it’s a few hrs. Not sure about Verizon.

 

[dave006]

Just to clarify on AT&T the calls show up under the iPhone's number for incoming calls and on the Watch's phone number for calls that actually happen directly from the Watch.

On AT&T they distinguish between Cellular Calls and Wi-Fi Calls from the Watch, on the Watch initiated Wi-Fi Calls should be indicated as SPWIFI (NumberSync Wi-Fi). I have not successfully had one of these logged by AT&T.

Dave

 

[Smoothie]

An update. I put my iPhone in airplane mode and went outside beyond WiFi range but close enough for me to be within range of my cordless landline phone (remember them?). The watch switched to LTE. I called myself by dialing my iPhone number and the watch rang. So far so good. Then I went back inside with the iPhone still in airplane mode, and the watch dropped LTE and connected to WiFi as it should (although it took a few minutes and finally connected when I tried accessing weather data). I then called my iPhone number again using my landline. This time -- for the first time -- the watch rang. Unfortunately, I didn't answer the phone in each case so it won't show up on the billing records to see which number the WiFi incoming call got assigned to. In any case, I hope these settings hold and I'm still able to receive calls over WiFi when the phone isn't connected to the cellular network or the watch.
[doublepost=1508019546][/doublepost]Crap. It just occurred to me that the first test of the incoming call on the LTE network shouldn't have worked since I think the phone has to be connected to the LTE network for the watch to use LTE. So it's possible that I was still marginally connected to WiFi even though the watch was showing the LTE signal. I'll be far from my house tonight so I'll try again then. But the issue for me was WiFi calling, so that seems to be working both inbound and outbound at the moment. This watch is giving me a headache.

 

[dave006]

Good input. Is it possible that this was the first time your Watch actually had a LTE signal? On a Carrier network, they can't route calls to a device that has not already registered to the network.

One quick test, could you disable your LTE using the Cellular Toggle on your Watch while having your iPhone in Airplane mode and see if your Watch does actually receive in inbound Wi-Fi Call. In my case it does not work.

Dave

 

[deadworlds]

An update. I put my iPhone in airplane mode and went outside beyond WiFi range but close enough for me to be within range of my cordless landline phone (remember them?). The watch switched to LTE. I called myself by dialing my iPhone number and the watch rang. So far so good. Then I went back inside with the iPhone still in airplane mode, and the watch dropped LTE and connected to WiFi as it should (although it took a few minutes and finally connected when I tried accessing weather data). I then called my iPhone number again using my landline. This time -- for the first time -- the watch rang. Unfortunately, I didn't answer the phone in each case so it won't show up on the billing records to see which number the WiFi incoming call got assigned to. In any case, I hope these settings hold and I'm still able to receive calls over WiFi when the phone isn't connected to the cellular network or the watch.
[doublepost=1508019546][/doublepost]Crap. It just occurred to me that the first test of the incoming call on the LTE network shouldn't have worked since I think the phone has to be connected to the LTE network for the watch to use LTE. So it's possible that I was still marginally connected to WiFi even though the watch was showing the LTE signal. I'll be far from my house tonight so I'll try again then. But the issue for me was WiFi calling, so that seems to be working both inbound and outbound at the moment. This watch is giving me a headache.

Phone does not have to be on LTE for the watch to work LTE. Your phone can even be off and the watch would use it’s own LTE to receive and make calls. You just won’t get SMS texts or notifications when phone is off. iMessage will work though.

 

[ZipZap]

Just to clarify on AT&T the calls show up under the iPhone's number for incoming calls and on the Watch's phone number for calls that actually happen directly from the Watch.

On AT&T they distinguish between Cellular Calls and Wi-Fi Calls from the Watch, on the Watch initiated Wi-Fi Calls should be indicated as SPWIFI (NumberSync Wi-Fi). I have not successfully had one of these logged by AT&T.

Dave

I concur. I shut my phone this morning. I saw on the watch the WIFI indicator. I made a call on the watch. It went through. I just checked a minute ago and that call was logged on the watch account as a NW call. So it was not a WIFI call, even though the WIFI indicator was clearly visible on the watch. If I shut off the cell service on the watch, no "so called" WIFI calls go through. Clearly and issue with AT&T Number Sync.

 

[deadworlds]

I concur. I shut my phone this morning. I saw on the watch the WIFI indicator. I made a call on the watch. It went through. I just checked a minute ago and that call was logged on the watch account as a NW call. So it was not a WIFI call, even though the WIFI indicator was clearly visible on the watch. If I shut off the cell service on the watch, no "so called" WIFI calls go through. Clearly and issue with AT&T Number Sync.

This is the same issue we are all experiencing. Do me a favor, put your iPhone in airplane mode, alternatively turn off the WiFi and Bluetooth radios. Wait for your watch to switch to WiFi and make sure the cellular toggle is in the ON position.

Now, on the watch, go to settings -> General -> About. Scroll down to where it says “Network” what does it say?

Second, on the watch, now turn the cellular toggle to OFF. Go watch into the watch settings->General -> about. Now what does it say under network?

 

[dave006]

... Clearly and issue with AT&T Number Sync.

The real issue is how Apple is managing the Wi-Fi Calling on the LTE Watches. It appears that Apple disables Wi-Fi calling for the Watch.

Sorry but not an issue with AT&T NumberSync. It is an issue for Apple and controlling Wi-Fi calling when the Watch is provisioned with a Carrier Plan.

Last week, I spent many hours with AT&T Tech support and we completely removed everything about my Watch and I went back through the normal iPhone Watch app to setup the Watch, provision the eSIM and complete NumberSync. NumberSync works correctly for all aspects that we can control beyond Apple.

Dave

 

[sirozha]

No the issue is that the Toggle is not shown if the active Watch has a Carrier plan. We have proven the behavior by removing the Carrier plan, the Wi-Fi calling option appears. Re-add the Carrier Plan and the Toggle is gone.

You might want to go back and re-read my post. I suggested: remove the SIM from your iPhone and try to make a Wi-Fi call. It will not work! Sorry, your test on a Cellular iPad is a nice random data point but is not relevant to this discussion.

The Cellular iPad is a "Data" only device from the Carrier provisioning standpoint, It does not have Voice / Talk enabled for Cellular calls. Your test using FaceTime Wi-Fi calling is actually exactly how it should perform as documented by Apple, so no issue or positive indication of anything relating to the LTE Watch.

Again, you have proven nothing yet about how devices like the LTE Watch and the iPhone with Voice/Data SIM(s) from the Carrier perform Wi-Fi Calling. Let us know how your iPhone works when you remove the SIM Card and try to make a Wi-Fi call.

Please keep us posted as we all want the LTE Watch to perform correctly and use direct Wi-Fi calling from the Carrier before failing over to LTE to save the battery.

Dave

The bottom line here is that once an LTE plan is activated on the LTE Apple Watch Series 3, the Wi-Fi calling method is no longer based on the iCloud account with which the Apple Watch is associated. Instead, the service-provoder based Wi-Fi calling is used for this. With the Series 2 Apple Watch and with the Series 3 Apple watch (without LTE or with LTE plan removed), the Wi-Fi calling method is based on the iCloud account. So, whereas the device-to-main number association in the latter case is done by iCloud, the device-to-main number associate in the former case is done by the service provider's systems such as NumberSync or DIGITS.

So, we are talking here about two different methods of Wi-Fi calling. iPad, Mac, and Apple Watch 2 (as well as Apple Watch 3 without LTE or with LTE plan removed) use iCloud-based device association with the main number. Apple Watch 3 with LTE activated uses the Service-Provider method of associating a device with the main number. When the Apple Watch Series 3 with LTE activated makes a Wi-Fi call, the call arrives in the Service Provider's network with the calling device being identified by a fake number that carriers assign to the LTE Apple Watch. This fake number is then mapped by the service provider's system to the main number.

 

[dave006]

....Now, on the watch, go to settings -> General -> About. Scroll down to where it says “Network” what does it say? ?

On the iPhone it shows correctly: AT&T Wi-Fi

Second, on the watch, now turn the cellular toggle to OFF. Go watch into the watch settings->General -> about. Now what does it say under network?

On the Watch it shows: Not available, under both conditions.

Dave

 

[deadworlds]

On the iPhone it shows correctly: AT&T Wi-Fi



On the Watch it shows: Not available, under both conditions.

Dave

Even when the watch is on WiFi and cellular is on? On mine, when on WiFi with cellular on it will say, in the watch settings “t-mobile WiFi”

When I turn the cellular toggle off on the watch, but still on WiFi, it reads “not available”.

 

[dave006]

For the first time I am able to now get the AT&T Wi-Fi to show on the Watch.

Here is the rest of the story: While looking at a problem in another thread, I saw that my Watch's line had and odd Feature set for it's Data. It was set to Stream Saver Mode; an AT&T setting that limits the speed of Data when it senses Video streaming. I disabled it and then restarted my Watch yet again, and I now see the correct setting.

As usual, I made what should be a Wi-Fi Call from the Watch while my iPhone is in Airplane mode, now I wait to check the call detail in about 3 hours.

Dave

 

[sirozha]

I'm not going to dignify with a response the petty and ignorant attacks and will move on to the bottom line.

I have three active iPhones, an iPad, two Macs, and four Apple watches (two Series 2 and two Series 3 with LTE activated through T-Mobile). I have conducted exhaustive tests with all of my devices vis-a-vis all sorts of different calling modes on all of my devices and I have arrived at the following conclusions.

First I want to lay out the different calling modes:
Mode 0 - Purely cellular-based calling. This mode can be used by mobile phones (iPhones, Android phones, etc.), Series 3 Apple Watches with LTE activated (while out of range of iPhone and out of range of a known Wi-Fi), and some Android watches.
Mode 1 - Bluetooth calling. This mode is automatic for all Apple Watches paired with an iPhone. It probably works in the same way between Samsung phones and Samsung watches, but this fact is irrelevant to this topic.
Mode 2 - Wi-Fi calling while on the same Wi-Fi as the iPhone. This mode works exclusively with Apple devices and requires that another device be logged in to the same iCloud account as the iPhone that has the SIM with an active cellular service installed in it. The Apple devices that work with this mode are: Macs, iPads, other iPhones, and probably iPod Touch. Apple Watches can use this mode as well because they are logged in to the same iCloud account as the iPhone with an active cellular service during the Apple Watch pairing with iPhone procedure.
Mode 3 - Wi-Fi calling while on any Wi-Fi (doesn't have to be the same Wi-Fi as iPhone). This mode is now called by apple Wi-Fi Calls on Other Devices. This mode can be used by Macs, iPads, non-LTE Apple Watches as well as LTE-capable Apple Watches that are not activated on LTE, and probably by the iPod Touch. In my test, another iPhone logged in to the same iCloud account did not ring in this scenario; hence, from my testing, it does not appear that other iPhones are capable of Mode 3 calling. The differentiator between Mode 3 and Mode 2 is the enablement of Wi-Fi Calling on the iPhone that has the SIM with the number to be shared with other devices. The enablement of Wi-Fi Calling on such a phone allows it to make Wi-Fi calls, but it also allows other devices listed above to make Wi-Fi calls even when not in proximity to the iPhone (e.g. from other Wi-Fi networks). In fact, the main iPhone does not even have to be turned on. This feature is proprietary to Apple, but it requires assistance by the carrier, and not all carriers support this feature.
Mode 4 - Carrier-proprietary Wi-Fi calling (equipment agnostic). This mode works for any computer (Apple or Wintel), any phone (Apple or Android), any tablet (Apple, Windows, or Android), and LTE Series 3 Apple Watch with LTE activated through a carrier. This mode does not require that the device be logged in to the same iCloud account as the main iPhone. Every carrier has its own proprietary system that enables Mode 4. For example, T-Mobile makes this happen on computers, tablets, other phones (both iPhones and Android phones) via the DIGITS application that must run on each such device. On the LTE Series 3 Apple Watch, this mode is enabled via the Watch app when the cellular plan is activated there. For this mode to work, the non-mobile phone device must be on a Wi-Fi network, but the mobile phone itself does not have to be on the same Wi-Fi; in fact, the mobile phone can even be turned off.

-----------------
Prior to the release of LTE-capable Series 3 Apple Watch, Apple Watches were capable of the following calling modes:
Mode 1 - Bluetooth Calling. For this mode to work, the Apple Watch must be paired with the iPhone
Mode 2 - Wi-Fi Calling while on the same Wi-Fi as the iPhone. For this mode to work on the Apple Watch, Calls on Other Devices must be enabled in iPhone Settings > Phone. Additionally, Wi-Fi Calling must be enabled in the Watch App > My Watch (tab) > Phone and the iPhone must be powered on.
Mode 3 - Wi-Fi Calling while on any Wi-Fi. For this mode to work on the Apple Watch, Wi-Fi Calling AND Calls on Other Devices must be enabled in iPhone Settings > Phone. Additionally, Wi-Fi Calling must be enabled in the Watch App > My Watch (tab) > Phone. The iPhone does not have to be powered on, and the Apple Watch can be on any Wi-Fi known to it so that it can join that Wi-Fi automatically.

With the LTE Series 3 Apple watch, things got even more complicated. If the LTE feature is not activated through the carrier, then the LTE Series 3 Apple watch functions the same as a non-LTE Series 3 Apple Watch and the same as a Series 2 Apple watch (and earlier Series Apple Watch). That is, as long as LTE is not activated through the carrier in the Series 3 Apple Watch, it is capable of Mode 1, Mode 2, and Mode 3.

As soon as LTE is activated through the carrier on the Series 3 Apple Watch, its capabilities change, and the Series 3 Apple Watch with LTE activated is capable of the following calling modes:
Mode 0 - Pure cellular calls when the Apple Watch is not in proximity to the iPhone or to a known Wi-Fi network that it can join.
Mode 1 - Bluetooth Calling. For this mode to work, the Apple Watch must be paired with the iPhone
Mode 2 - Wi-Fi Calling while on the same Wi-Fi as the iPhone. For this mode to work on the Series 3 Apple Watch with LTE activated, Calls on Other Devices must be enabled in iPhone Settings > Phone. Note that the Wi-Fi Calling toggle disappears from the Watch App > My Watch (tab) > Phone, so there is no way to turn off this mode, but this mode is enabled by default. The iPhone must be powered on.
Mode 4 - Carrier-propietary Wi-Fi Calling (equipment agnostic). This mode is automatically enabled when the LTE Series 3 Apple Watch is activated on LTE through the carrier. This mode kicks in when the LTE Series 3 Apple watch cannot communicate with the iPhone (via Bluetooth or Wi-Fi), but when the Watch can join a known Wi-Fi. There is no toggle to turn off this mode, but when the "Antenna" toggle is switched off in the Watch's Control Center, both Mode 0 and Mode 4 are turned off.

----------------------------------
There is one cosmetic issue remaining with a toggle for the non-active Apple Watches (Series 2 and Series 3) showing up in IOS 11 in iPhone Settings > Phone > Calls on Other Devices. After extensive testing, I believe this toggle is cosmetic when it comes to controlling Wi-Fi calling (of any nature) on the LTE Series 3 Apple Watch with LTE activated through the carrier. I do not believe this toggle does anything, and this is most likely a bug. There are two very vocal users here who just HATE any mention of this toggle, and I won't name any names here lest they should launch their hateful tirades once again. But I digress.
----------------------------------

As for the functionality of the LTE Series 3 Watch with LTE activated though T-Mobile, my findings are as follows:
Mode 0: Works flawlessly
Mode 1: Works flawlessly
Mode 2: Works flawlessly
Mode 3: This mode does not apply to the LTE Series 3 Watch with LTE activated through a carrier.
Mode 4: This mode works well, but I think Apple can improve it. The issues that I've run into are:
a. After LTE is activated through a carrier (in my case T-Mobile), this mode does not appear to work. The test that I made was to place the iPhone in Airplane Mode and call my iPhone number from a landline. The phone call rang on my Mac (in Mode 3), my iPad (in Mode 3), but it did not ring on my LTE Series 3 Apple Watch. Neither could I make a call from my LTE Series 3 Apple Watch. There is a very simple fix for this, and I have tried this fix three times now. All you have to do is take your iPhone out of the Airplane Mode, reboot your Watch and while it's rebooting, reboot your iPhone. The iPhone will come back on first, followed by the Watch. At this point, log in to the iPhone and put it in Airplane mode. Now wait for 2-3 minutes, and then place a call to your iPhone number (or make a call from your Watch). The calls should be working fine from now on - until you decide to remove the cellular plan from your Watch in the Watch App. If you remove the cellular plan, and then re-enable the cellular plan through the Watch app, you would have to follow this procedure again.
b. When you turn off your iPhone or put it in Airplane Mode, there is a 2-3 minute delay in the ability of the Watch to make or receive calls. This convergence period is too long in my opinion, as it should be measured in seconds rather than in minutes. However, even with the Series 2 Apple watch, the transition to Wi-Fi calling (in the case of Series 2 it's Mode 3) also takes the same 2-3 minutes in my testing.

-------------------------------------
There has been an extensive discussion in this thread whether the LTE Series 3 Apple Watch with LTE activated though a carrier is actually performing Mode 4 or if it is performing Mode 0 when the iPhone is in Airplane Mode (or powered down), but the Watch is joined to a known to it Wi-Fi. There is no 100% certainty in this, but from my tests, I am 99% sure that it is Mode 4 that is used in this scenario. I use the Explorer watch face to monitor for the active LTE connection on the watch, and in this use case, the LTE signal strength indicator never shows up on the Explorer watch face. Conversely, when I walk on a forest trail while having left my iPhone in the car and with no Wi-Fi available to the Apple Watch, the Explorer watch face shows LTE signal strength indicator, which correlates with the fact that the Watch makes and receives calls using Mode 0 in that scenario.

As for how each carrier characterizes calls made from (or received on) the LTE Series 3 Apple watch with LTE activated while the iPhone is powered down (or in Airplane mode), the information displayed in the user portal is specific to each carrier and does not necessarily reflect the true nature of the Apple Watch call: Mode 0 or Mode 4.
--------------------------------------

I have tested two LTE Series 3 Apple Watches with LTE activated through T-Mobile (each paired to a separate iPhone on the T-Mobile One Plus plans), and I am not experiencing ANY issues whatsoever other than a 2-3 minute delay when transitioning to Mode 4 after I put the iPhones in Airplane Mode (or turn them off).

 

[deadworlds]

I'm not going to dignify with a response the petty and ignorant attacks and will move on to the bottom line.

I have three active iPhones, an iPad, two Macs, and four Apple watches (two Series 2 and two Series 3 with LTE activated through T-Mobile). I have conducted exhaustive tests with all of my devices vis-a-vis all sorts of different calling modes on all of my devices and I have arrived at the following conclusions.

First I want to lay out the different calling modes:
Mode 0 - Purely cellular-based calling. This mode can be used by mobile phones (iPhones, Android phones, etc.), Series 3 Apple Watches with LTE activated (while out of range of iPhone and out of range of a known Wi-Fi), and some Android watches.
Mode 1 - Bluetooth calling. This mode is automatic for all Apple Watches paired with an iPhone. It probably works in the same way between Samsung phones and Samsung watches, but this fact is irrelevant to this topic.
Mode 2 - Wi-Fi calling while on the same Wi-Fi as the iPhone. This mode works exclusively with Apple devices and requires that another device be logged in to the same iCloud account as the iPhone that has the SIM with an active cellular service installed in it. The Apple devices that work with this mode are: Macs, iPads, other iPhones, and probably iPod Touch. Apple Watches can use this mode as well because they are logged in to the same iCloud account as the iPhone with an active cellular service during the Apple Watch activation procedure.
Mode 3 - Wi-Fi calling while on any Wi-Fi (doesn't have to be the same Wi-Fi as iPhone). This mode is now called by apple Wi-Fi Calls on Other Devices. This mode can be used by Macs, iPads, non-LTE Apple Watches as well as LTE-capable Apple Watches that are not activated on LTE, and probably by the iPod Touch. In my test, another iPhone logged in to the same iCloud account did not ring in this scenario; hence, from my testing, it does not appear that other iPhones are capable of Mode 3 calling. The differentiator between Mode 3 and Mode 2 is the enablement of Wi-Fi Calling on the iPhone that has the SIM with the number to be shared with other devices. The enablement of Wi-Fi Calling on such a phone allows it to make Wi-Fi calls, but it also allows other devices listed above to make Wi-Fi calls even when not in proximity to the iPhone (e.g. from other Wi-Fi networks). In fact, the main iPhone does not even have to be turned on. This feature is proprietary to Apple, but it requires assistance by the carrier, and not all carriers support this feature.
Mode 4 - Carrier-proprietary Wi-Fi calling (equipment agnostic). This mode works for any computer (Apple or Wintel), any phone (Apple or Android), any tablet (Apple, Windows, or Android), and LTE Series 3 Apple Watch with LTE activated through a carrier. This mode does not require that the device be logged in to the same iCloud account as the main iPhone. Every carrier has its own proprietary system that enables Mode 4. For example, T-Mobile makes this happen on computers, tablets, other phones (both iPhones and Android phones) via the DIGITS application that must run on each such device. On the LTE Series 3 Apple Watch, this mode is enabled via the Watch app when the cellular plan is activated there. For this mode to work, the non-mobile phone device must be on a Wi-Fi network, but the mobile phone itself does not have to be on the same Wi-Fi; in fact, the mobile phone can even be turned off.

-----------------
Prior to the release of LTE-capable Series 3 Apple Watch, Apple Watches were capable of the following calling modes:
Mode 1 - Bluetooth Calling. For this mode to work, the Apple Watch must be paired with the iPhone
Mode 2 - Wi-Fi Calling while on the same Wi-Fi as the iPhone. For this mode to work on the Apple Watch, Calls on Other Devices must be enabled in iPhone Settings > Phone. Additionally, Wi-Fi Calling must be enabled in the Watch App > My Watch (tab) > Phone and the iPhone must be powered on.
Mode 3 - Wi-Fi Calling while on any Wi-Fi. For this mode to work on the Apple Watch, Wi-Fi Calling AND Calls on Other Devices must be enabled in iPhone Settings > Phone. Additionally, Wi-Fi Calling must be enabled in the Watch App > My Watch (tab) > Phone. The iPhone does not have to be powered on, and the Apple Watch can be on any Wi-Fi known to it so that it can join that Wi-Fi automatically.

With the LTE Series 3 Apple watch, things got even more complicated. If the LTE feature is not activated through the carrier, then the LTE Series 3 Apple watch functions the same as a non-LTE Series 3 Apple Watch and the same as a Series 2 Apple watch (and earlier Series Apple Watch). That is, as long as LTE is not activated through the carrier in the Series 3 Apple Watch, it is capable of Mode 1, Mode 2, and Mode 3.

As soon as LTE is activated through the carrier on the Series 3 Apple Watch, its capabilities change, and the Series 3 Apple Watch with LTE activated is capable of the following calling modes:
Mode 0 - Pure cellular calls when the Apple Watch is not in proximity to the iPhone or to a known Wi-Fi network that it can join.
Mode 1 - Bluetooth Calling. For this mode to work, the Apple Watch must be paired with the iPhone
Mode 2 - Wi-Fi Calling while on the same Wi-Fi as the iPhone. For this mode to work on the Series 3 Apple Watch with LTE activated, Calls on Other Devices must be enabled in iPhone Settings > Phone. Note that the Wi-Fi Calling toggle disappears from the Watch App > My Watch (tab) > Phone, so there is no way to turn off this mode, but this mode is enabled by default. The iPhone must be powered on.
Mode 4 - Carrier-propietary Wi-Fi Calling (equipment agnostic). This mode is automatically enabled when the LTE Series 3 Apple Watch is activated on LTE through the carrier. This mode kicks in when the LTE Series 3 Apple watch cannot communicate with the iPhone (via Bluetooth or Wi-Fi), but when the Watch can join a known Wi-Fi. There is no toggle to turn off this mode, but when the "Antenna" toggle is switched off in the Watch's Control Center, both Mode 0 and Mode 4 are turned off.

----------------------------------
There is one cosmetic issue remaining with a toggle for the non-active Apple Watches (Series 2 and Series 3) showing up in IOS 11 in iPhone Settings > Phone > Calls on Other Devices. After extensive testing, I believe this toggle is cosmetic when it comes to controlling Wi-Fi calling (of any nature) on the LTE Series 3 Apple Watch with LTE activated through the carrier. I do not believe this toggle does anything, and this is most likely a bug. There are two very vocal users here who just HATE any mention of this toggle, and I won't name any names here lest they should launch their hateful tirades once again. But I digress.
----------------------------------

As for the functionality of the LTE Series 3 Watch with LTE activated though T-Mobile, my findings are as follows:
Mode 0: Works flawlessly
Mode 1: Works flawlessly
Mode 2: Works flawlessly
Mode 3: This mode does not apply to the LTE Series 3 Watch with LTE activated through a carrier.
Mode 4: This mode works well, but I think Apple can improve it. The issues that I've run into are:
a. After LTE is activated through a carrier (in my case T-Mobile), this mode does not appear to work. The test that I made was to place the iPhone in Airplane Mode and call my iPhone number from a landline. The phone call rang on my Mac (in Mode 3), my iPad (in Mode 3), but it did not ring on my LTE Series 3 Apple Watch. Neither could I make a call from my LTE Series 3 Apple Watch. There is a very simple fix for this, and I have tried this fix three times now. All you have to do is take your iPhone out of the Airplane Mode, reboot your Watch and while it's rebooting, reboot your iPhone. The iPhone will come back on first, followed by the Watch. At this point, log in to the iPhone and put it in Airplane mode. Now wait for 2-3 minutes, and then place a call to your iPhone number (or make a call from your Watch). The calls should be working fine from now on - until you decide to remove the cellular plan from your Watch in the Watch App. If you remove the cellular plan, and then re-enable the cellular plan through the Watch app, you would have to follow this procedure again.
b. When you turn off your iPhone or put it in Airplane Mode, there is a 2-3 minute delay in the ability of the Watch to make or receive calls. This conversion period is too long in my opinion, as it should be measured in seconds rather than in minutes. However, even with the Series 2 Apple watch, the transition to Wi-Fi calling (in the case of Series 2 it's Mode 3) also takes the same 2-3 minutes in my testing.

-------------------------------------
There has been an extensive discussion in this thread whether the LTE Series 3 Apple Watch with LTE activated though a carrier is actually performing Mode 4 or if it is performing Mode 0 when the iPhone is in Airplane Mode (or powered down), but the Watch is joined to a known to it Wi-Fi. There is no 100% certainty in this, but from my tests, I am 99% sure that it is Mode 4 that is used in this scenario. I use the Explorer watch face to monitor for the active LTE connection on the watch, and in this use case, the LTE signal strength indicate never shows up on the Explorer watch face. Conversely, when I walk on a forest trail while having left my iPhone in the car and with no Wi-Fi available to the Apple Watch, the Explorer watch face shows LTE signal strength indicator, which correlates with the fact that the Watch makes and receives calls using Mode 0 in that scenario.

As for how each carrier characterizes calls made from (or received on) the LTE Series 3 Apple watch with LTE activated while the iPhone is powered down (or in Airplane mode), the information displayed in the user portal is specific to each carrier and does not necessarily reflect the true nature of the Apple Watch call: Mode 0 or Mode 4.
--------------------------------------

I have tested two LTE Series 3 Apple Watches with LTE activated through T-Mobile (each paired to a separate iPhone on the T-Mobile One Plus plans), and I am not experiencing ANY issues whatsoever other than a 2-3 minute delay when transitioning to Mode 4 after I put the iPhones in Airplane Mode (or turn them off).

Your post is very detailed and provided a lot of information. I think mode 4 is where we are experiencing some weird behavior.

On my watch, if connected to WiFi, while phone is in airplane mode, and I turn off the cellular toggle on the watch, it will refuse to place a call over WiFi. Do you experiencing the same? If so, what do you attribute this behavior to?