Poor cell reception

[tcuprof]

I recently returned from a trip to Chile. It was my first time out of the country with my iPhone 15 Pro. While in San Pedro and the area, my cell phone reception was terrible. Repeatedly, I would be the only one in the group with no cell signal. I have a picture and a screenshot where we're literally sitting under a cell tower. Everyone in my group has five bars and I have NO signal.

It seems there are two possibilities - the phone has a faulty antenna or my carrier (T-Mobile) is the problem. I don't think it is T-Mobile's fault because they have a partnership with the two major carriers where we were - Claro and Movistar. I know this because when I DID get a cell signal, I would check and it was always one of these two carriers. Even at home, my signal is weak. The nearest T-Mobile cell tower is .9 miles from my house and yet I get 1-2 bars. I couldn't make calls reliably without wi-fi calling.

I suspect if I go to Apple, they will blame T-Mobile and likewise T-Mobile will blame the phone.

Suggestions?

 

[Just_Me_D]

It’s hard to say, but under the circumstances you mentioned, all blame points to the iPhone, especially if others are maintaining a cell signal and you are not. If you have a case on the device, did you try taking it off to see if the reception improved?

 

[EdwinG]

There are two possibilities (for the Chile part of your post). Both having no actionable solutions.

Your iPhone doesn’t support the same frequencies that the mobile phone tower was broadcasting on.
Not all iPhones support the same bands; so if your phone doesn’t support it, it won’t even see the tower.

iPhone - Supported 5G and LTE networks

See the countries and regions that have certified 5G and LTE networks on iPhone including the U.S., Canada, Japan, Germany, China mainland and more.

www.apple.com

Also, another possibility is that you are too close to the tower. This could be overpowering the modem on your phone and causing it to either (a) rejecting the signal, or (b) adjusting the power level to avoid damage. That depends on how it is implemented on the device.

 

[tcuprof]

If you have a case on the device, did you try taking it off to see if the reception improved?

I do. I did. It didn't.

 

[tcuprof]

There are two possibilities (for the Chile part of your post). Both having no actionable solutions.

Your iPhone doesn’t support the same frequencies that the mobile phone tower was broadcasting on.
Not all iPhones support the same bands; so if your phone doesn’t support it, it won’t even see the tower.

iPhone - Supported 5G and LTE networks

See the countries and regions that have certified 5G and LTE networks on iPhone including the U.S., Canada, Japan, Germany, China mainland and more.

www.apple.com

Also, another possibility is that you are too close to the tower. This could be overpowering the modem on your phone and causing it to either (a) rejecting the signal, or (b) adjusting the power level to avoid damage. That depends on how it is implemented on the device.

I was the only one in the group with a 15. Two others in my groups have a 14 and a 13, and they got a 5 bar signal, suggesting the signal wasn't overpowering their phone. Is it possible the 15 would not support frequencies that a 14 and 13 would??? What is possible is that the tower we were near was neither Claro or Movistar (although I'm not aware of any other providers in San Pedro) and so my friends who are on Verizon might have been able to receive that provider.

At this point, I still lean towards subpar cell reception.

 

[EdwinG]

Is it possible the 15 would not support frequencies that a 14 and 13 would???

It is possible.

It depends what sub models of the iPhone they are. For instance, A3101 [iPhone 15 Pro CA] has no support for 5G mmWave frequencies, whereas A2649 [iPhone 14 US] does.

What is possible is that the tower we were near was neither Claro or Movistar (although I'm not aware of any other providers in San Pedro) and so my friends who are on Verizon might have been able to receive that provider.

Maybe T-Mobile has no roaming agreement in place with that carrier, but Verizon does. That’s also possible.

When I travel to the USA, I can only roam on AT&T and T-Mobile. My phone will refuse connecting to Verizon even if they are the only available network.

Keep in mind that different phones have different thresholds for power levels, but it shouldn’t be a big difference. I would put that one aside

 

[doogald]

While I always hate suggesting this unless it's the last straw, one thing to try is Settings / General / Transfer or Reset phone / Reset (at the bottom) and Reset Network Settings.

Unfortunately this clears all WiFi access point stored passphrase (which is why I hate suggesting it). But it also resets the cellular/mobile network settings and I've seem similar cellular issues (with older iPhones) that were fixed by doing this.

 

[EdwinG]

Unfortunately this clears all WiFi access point stored passphrase (which is why I hate suggesting it)

A little precision: it no longer clears the stored WiFi network list, if they are stored in iCloud Keychain (or provisioned by a entreprise mobile device management service).

More specifically, it does, but it gets reconfigured immediately, so it is almost unnoticeable.

 

[o4liberty]

I am getting great cell service with mine so far no complaints.

 

[tcuprof]

I’m currently on an Australia/New Zealand cruise, and I am increasingly convinced my 15 pro has cell and wifi reception problems. The wifi signal is very strong and there is nowhere on this ship that I don‘t get a full-strength signal. And yet, it drops the connection frequently. As in, it connects, shows a strong connection, and then moments later, from the same location, it loses the signal. Worse, it doesn’t just reconnect later as is typical with a dropped cell signal. It disconnects and has to be logged on again from scratch. I do not believe this is the fault of the ship’s wifi, because my wife’s 13-mini has never once dropped the signal. I’d like to have my 14 Pro back!

 

[EdwinG]

I’m currently on an Australia/New Zealand cruise, and I am increasingly convinced my 15 pro has cell and wifi reception problems. The wifi signal is very strong and there is nowhere on this ship that I don‘t get a full-strength signal. And yet, it drops the connection frequently. As in, it connects, shows a strong connection, and then moments later, from the same location, it loses the signal. Worse, it doesn’t just reconnect later as is typical with a dropped cell signal. It disconnects and has to be logged on again from scratch. I do not believe this is the fault of the ship’s wifi, because my wife’s 13-mini has never once dropped the signal. I’d like to have my 14 Pro back!

At this point, I would bring it to your local Apple Store (not Australian, New Zealand) to have it looked at.

 

[Trees]

You've done a great job trying to figure this out. As EdwinG suggests, getting Apple Support to take a look is a good next step.

For consideration, the other potential variables at play could be iOS version, cellular modem, Wi-Fi chip (assuming it is separate from the modem), and wireless network settings.

Hope this helps, and understand firsthand having to worry about connectivity while traveling away from home.

• iOS versions
  • If iPhone 13 and 15 have different versions.
• iPhone 15 modem
  • Appears to be a Qualcomm Snapdragon X70
    • https://www.theverge.com/2023/9/15/23875787/iphone-15-pro-better-5g-connectivity
• iPhone 13 modem
  • Appears to be a Qualcom X60
    • https://www.pcmag.com/news/teardown-confirms-qualcomm-modems-in-the-iphone-13-pro
• Wi-Fi chip
  • iPhone 15
    • May be Apple according to https://www.ifixit.com/Guide/iPhone+15+Pro+Max+Chip+ID/165320
      • "Possibly Apple 339S01232 WiFi & Bluetooth module"
  • iPhone 13
    • May be various vendors according to
      • https://appleinsider.com/articles/21/07/15/iphone-13-to-use-wi-fi-6e-technology
• Wireless network settings
  • Wi-Fi Assist
    • Settings/Cellular (you may have to scroll "way down" to see it beneath the "Cellular Data" section
      • "Automatically use cellular data when Wi-Fi connectivity is poor."
        • Although this does not seem to the case onboard the ship.
  • DNS, VPN or Wi-Fi 6
    • The article below lists changing settings for these areas may help.
      • https://discussions.apple.com/thread/255148144?sortBy=best

 

[doogald]

A little precision: it no longer clears the stored WiFi network list, if they are stored in iCloud Keychain (or provisioned by a entreprise mobile device management service).

More specifically, it does, but it gets reconfigured immediately, so it is almost unnoticeable.

Thank you! This ended up solving a problem I was having (not on a 15 model, bit a 13 Pro, and I just read this message, so I'm just now learning why). If I was away from a wifi access point for a long period of time (generally a week), when I returned my phone would not reconnect, and I would be required to re-enter the passphrase. Resetting network settings didn't solve it; factory reset and restore didn't solve it; factory reset and rebuild from scratch also didn't solve it.

Finally hitting Settings / WiFi, Edit, and deleting the items one at a time ended up fixing it - though it took a long time to test each one, as I had to go up to my summer house and see if I reconnected when I got there.

Such a PITA.

 

[tcuprof]

While I always hate suggesting this unless it's the last straw, one thing to try is Settings / General / Transfer or Reset phone / Reset (at the bottom) and Reset Network Settings.

Unfortunately this clears all WiFi access point stored passphrase (which is why I hate suggesting it). But it also resets the cellular/mobile network settings and I've seem similar cellular issues (with older iPhones) that were fixed by doing this.

I was aware of the possible benefits of resetting network settings, but really hated to for the reasons doogald stated. However, after reading EdwinG’s clarification, I did that yesterday. It may have helped. The wifi signal has only dropped once since then. Fingers crossed. And thanks to everyone for the helpful suggestions.

In other news, I cannot get my mail/calendar/contact apps to work. Every time I try to get mail, it sends me to my Exchange server host to log in. When I do, I get the dreaded “Unable to verify login information.” I worked on that for a couple of days before I finally gave up and downloaded Outlook. Fortunately, Outlook works perfectly and, BONUS, so far I like it better than the Apple apps.

Maybe I should start a thread: “Problems you may have with Apple devices when you travel abroad.”

 

[EdwinG]

In other news, I cannot get my mail/calendar/contact apps to work. Every time I try to get mail, it sends me to my Exchange server host to log in. When I do, I get the dreaded “Unable to verify login information.”

For the Exchange account, you might need to delete and recreate the account. It is particularly true if you’re required to use federated (understand, web page) or multifactor authentication.

 

[tcuprof]

For the Exchange account, you might need to delete and recreate the account. It is particularly true if you’re required to use federated (understand, web page) or multifactor authentication.

Good morning Edwin! You’re quite the early riser. Your suggestion is a good one. I tried it and it didn’t work. Even using MFA, it still says it is “Unable to verify login information.” What’s worse is that deleting the account also deleted all my contacts since they were on the exchange server. Fortunately, with the Outlook app, they’re all retrieved. I obviously don’t know why Mail is borked, but I’m guessing the MS Exchange server is not recognizing the ship’s wifi, or vice versa. No matter. The Outlook app is working just fine.

 

[Wotchered]

Why not make friends with the Wireless room guys ?

 

[tcuprof]

Why not make friends with the Wireless room guys ?

I’m afraid I don’t know to whom you are referring?

 

[Wotchered]

A vessel's communications centre is known as the wireless room. Those guys will know all there is to know about electromagnetic behaviour on the vessel.

 

[tcuprof]

I finally had a chance to go to Apple and get my phone checked. And, sure enough, I'm even more baffled now.

The "genius" ran diagnostics and showed me where all the communication components (cell modem, wifi, etc.) are working perfectly. Here's where it gets weird. As is protocol, she checked to make sure the phone is running the latest software, and promptly announced, "Here is the problem - at some point you have been running beta software. We find that 99% of the time there is a cell or wifi problem, it is due to either beta software or a VPN."

I swear I have NEVER installed beta software. EVER! How could that happen?!? So, I said, can I just wipe the phone and restore from my iCloud backup. Her answer, "No, because whatever is causing the problem will be in the backup. Your only solution is to erase all content and settings and set up the phone from scratch." I.E., re-download every app, put them where I want them, reprogram any customizations (e.g., Focus), etc. Needless to say, that is a LONG task I DO not look forward to!!! Unless someone here is another idea, I guess that is what I'll be doing tomorrow.