Cellular and sending texts

[PCtoMAC1]

My second AW, though my first with LTE. I have AT&T and noticed today that I wasn’t able to send a text message to a person that is on Verizon and uses an Android (so no iMessage) while I was without my iPhone.

Is that usual?

 

[jaytv111]

You can send SMS, but your phone needs to be on and connected to a data network (either wifi or cellular) while you're out on your Watch. If your phone is off, or it's not connected to data, then SMS won't work (I think they require a data connection to the phone for syncing purposes). On the other hand, calls will work even if the phone is off, same for iMessages and Facetime.

 

[Banglazed]

https://support.apple.com/en-us/HT205547

 

[Luba]

You can send SMS, but your phone needs to be on and connected to a data network (either wifi or cellular) while you're out on your Watch. If your phone is off, or it's not connected to data, then SMS won't work (I think they require a data connection to the phone for syncing purposes). On the other hand, calls will work even if the phone is off, same for iMessages and Facetime.

Trying to figure out why that is. What is not happening when iPhone is off? iMessages uses data (WiFi) or cell (LTE) so even if iPhone off. Calls use LTE and can use WiFi because we are required to turn WiFi Calling on. But why sending SMS need iPhone to be on?? I think you can get SMS if iPhone off.

 

[KarimLeVallois]

Trying to figure out why that is. What is not happening when iPhone is off? iMessages uses data (WiFi) or cell (LTE) so even if iPhone off. Calls use LTE and can use WiFi because we are required to turn WiFi Calling on. But why sending SMS need iPhone to be on?? I think you can get SMS if iPhone off.

Your phone forwards the SMS from your phone to watch, so that's why it needs to be on. iMessage is slightly different, so that's why you can receive them directly.

 

[tromboneaholic]

Trying to figure out why that is. What is not happening when iPhone is off? iMessages uses data (WiFi) or cell (LTE) so even if iPhone off. Calls use LTE and can use WiFi because we are required to turn WiFi Calling on. But why sending SMS need iPhone to be on?? I think you can get SMS if iPhone off.

It's due to a limitation of text messaging. SMS messages are transmitted in an empty space in the signal that your phone uses to negotiate a connection with the cell tower. That's why it's limited in length. SMS is an antiquated hack that has hung on for way too long.

 

[Cervontez]

I had an issue like this when I got my XS Max. What worked for me is logging out of iCloud on my phone, turning it off, restarting, then logging back into iCloud.

Edit. Just reread the tread. This fixed my issue with SMS not going to or out my watch. This is a bug in iOS 12. Phone still needs to be connected to data of some sort. Follow the steps I listed If you’re having problems with receiving SMS on your watch (whether it’s connected to the phone or cellular).