LG K10 Android 7.0 - WiFi Calling - Missed Calls when not charging

  • 21 July 2017
  • 4 replies

We started missing calls on both of our LG K10 phones after the Nougat update (firmware K42820f) when on WiFi calling and not plugged in to a charger.  We rely on WiFi calling since the cell service is too weak in our home.  After the Nougat update, both phones often do not ring for incoming calls after 20 minutes or so of sitting idle while not charging.  It seems like doze mode is inhibiting WiFi calling.


I'm an electrical/software engineer and tried all sorts of geeky things with no luck.  We have the T-Mobile Cellspot Wifi router, a strong signal, and fast cable Internet service.  Changing advanced WiFi settings to 100 ms beacon and DTIM 1 did not help (changed it back to the default of DTIM 3).


In the phone's advanced WiFi options, WiFi is set to stay on with the screen off.  I've tried Ignore Battery Optimizations on WiFi Calling, WiFi, and a bunch of other apps.  I am not using Greenify or anything that would make doze mode more aggressive.


I made a Llamalab Automate program to wake the phones up every 5 minutes for 15 seconds, and that seems to help but it doesn't totally solve the problem.


I am pretty sure it is a firmware problem related to doze.  I hope this post gets seen/forwarded to T-Mobile and LG engineering.




Best answer by tmo_chris 27 July 2017, 16:23

Thanks for trying that @chopperc​I am glad that you were able to get a CellSpot device. That is totally gonna help you at your home location. I am going to reach out to out LG content owner on this Wi-Fi sleep thing and see if I can get any further clarification.

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So after unsuccessfully trying alarm clock apps Automate/Tasker programs, and Wake on LAN packets to periodically wake our cell phones to keep them from missing incoming calls when on WiFI calling, I decided to try to get a 4G LTE CellSpot so I wouldn't have to use WiFi calling. 

I found ordering instructions on the T-Mobile Web site...  Order a Personal CellSpot​ .  I called my local Greensburg, PA, store in the afternoon to see if they had them in stock before I drove out.  They said that they definitely did.  I drove out in the evening, and the workers at the store said they never have them in stock.  It was better if I ordered it by calling T-Mobile so I wouldn't have to make the $25 deposit. 

I called T-Mobile support, and they said that there is a known system issue that they cannot enter the order online.  I would have to drive to a store or call back in 72 hours. 

A few months ago, we had to return a ZTE ZMax phone because the WiFi calling kept giving REG99 on ER081 errors.  It took about 5 calls and a few drives to the store  to get the order straightened out so we didn't have to pay for the replacement phone.  Unreal.

Oh my goodness! I am very sorry that you are having such a rough time just trying to get your phone to reliably receive calls through Wi-Fi calling. I don't currently see this specific issue listed as a known issue with the K10. Since it is happening with 2 devices and it started after the OS update, it is safe to say that this is definitely a device issue. I thank you for all the extra troubleshooting you did to try and resolve this issue and I feel silly for even asking this but, did you try deleting and re adding the Wi-Fi network on your phones after the update? Also, it is good to do a system cache wipe on the devices after a large OS wipe just to ensure that the phone is not trying to perform a task the way it would on a previous update due to the way it's reading it from the cached memory.

As for the issue regarding ordering a CellSpot, I sincerely apologize that you were unable to get this device ordered as easily as you should have been able to. The CellSpot would resolve your issues but you should still be able to use Wi-Fi calling when you are not in range of the CellSpot and not have to worry about your phone taking a nap on the job. I know it has been a few days since you posted this but did you ever get the chance to call us back to order it?

Hi tmo_chris,

Thanks for the response.  I did try deleting and re-adding the WiFi network on both phones as well as clearing the application cache.  I don't think there is a way to clear the cache partition on the LG K10.  Nothing worked. 

I would place money that the problem is an incorrect implementation of this to wake the phone from Doze mode for WiFi calling...

Android Developers Blog: How Google Cloud Messaging handles Doze in Android 6.0 Marshmallow

I did call back a few days later and successfully ordered the 4G LTE Cellspot.  It is a shame we have to give up on WiFi calling.  It just seems like it is not adequately tested and supported for a lot of phones and software versions. 


Thanks for trying that @chopperc​I am glad that you were able to get a CellSpot device. That is totally gonna help you at your home location. I am going to reach out to out LG content owner on this Wi-Fi sleep thing and see if I can get any further clarification.