Calls not received. Texts delayed.

[justinleon2113]

Hello. Just upgraded to the ZenFone 6 (Edition 30) over the new year and notice that many calls from family and friends are going straight to voicemail. I tested this with a friend in the room, and out of 5 attempts, only 3 made the phone ring. Many important calls for business do not ring at all. I am using Ultra Mobile (T-Mobile MVNO) and have done the usual run-around (reset phone, empty cache, check all settings for fowarding, DND, and such). Even on a fresh install, it is experiencing the same phenomenon. I tried a different phone and it seemed to consistently work...I'll keep testing.
I wanted to see if anyone else had issues with not getting calls or texts (irrespective of carrier) or if it could be just carrier issues for me. I have great coverage in my area, thus it is not like I am roaming or disconnected. Thank you for the help.

[jeff_carlile]

After a long visit with a T-Mobile mobile tech, it seems to me a core problem is that neither Zenfone 5 nor 6 have LTE bands 66 and 71 which the network relies on. Primarily 71. As the tech said "they drummed it into us in training that LTE 71 is the bread and butter of the T-Mobile network.
This is a software and not a hardware problem. It can be fixed with a firmware update ( or root).
@LP_ASUS is this too much to ask?

[skylerwolfe]

jeff.carlile

After a long visit with a T-Mobile mobile tech, it seems to me a core problem is that neither Zenfone 5 nor 6 have LTE bands 66 and 71 which the network relies on. Primarily 71. As the text said "they drummed it into us in training that LTE 71 is the bread and butter of the T-Mobile network.

This is a software and not a hardware problem. It can be fixed with a firmware update ( or root).

@LP_ASUS is this too much to ask?

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You can't add bands with a firmware update as that is hardware dependent. A software update absolutely could allow VoLTE as has been shown on XDA, but with any help from Asus it requires unlocking the bootloader and having root access to change the mbn on the device. Bands 66 and 71 aren't necessary for functionality on T-mobile, but would be necessary to have access to their entire coverage area. Without VoLTE, though, NO bands will be allowed access in the near future. Asus could do that, but if they decline to do so, it will unfortunately be up to the user to either move to another device or go through the steps to enable it on their own.

[petteyg359]

Radio bands are not hardware dependent, and have not been for a very long time. Qualcomm doesn't manufacture hundreds of variants of their chipsets with different bands enabled ({number of possible bands} !factorial). Just like your desktop or laptop Wi-Fi card, if you load the Japanese regulatory files, you can use channel 13 even though it is illegal in the U.S.

[skylerwolfe]

petteyg359

Radio bands are not hardware dependent, and have not been for a very long time. Qualcomm doesn't manufacture hundreds of variants of their chipsets with different bands enabled ({number of possible bands} !factorial). Just like your desktop or laptop Wi-Fi card, if you load the Japanese regulatory files, you can use channel 13 even though it is illegal in the U.S.

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Good to know. Not sure where I got that info. Thanks for the correction. It raises the obvious question as to why all legal bands (for a given region) would not be enabled by default for phones sold in that region. Stupid.

[esther_lee_1971]

Have there been any updates on this, Asus? It's really hard to try to log when there's not really consistency in when texts and calls are missed or delayed - I can't predict when my phone will decide it doesn't want to receive a call or not. Please advise as this issue has been going on for far too long!