[Q] Wonky LTE/Call performance on custom roms

[Double_a2013]

Every time I flash a custom ROM based on 4.16.X firmware I either lose LTE (though HSPA+ still works perfectly) or the ability to receive calls. I've tried ARHD, SD, the Stock WWE, and the US DEV edition, and all of them have exactly one of those issues (it's never both). I'm currently back on ATT stock 4.4.4 ROM (3.42.502.1 firmware), rooted, S-Off.

I thought flashing the WWE RUU before flashing a ROM like ARHD would be enough to upgrade the firmware, but maybe I'm missing something.

 

[redpoint73]

Every time I flash a custom ROM based on 4.16.X firmware I either lose LTE (though HSPA+ still works perfectly) or the ability to receive calls. I've tried ARHD, SD, the Stock WWE, and the US DEV edition, and all of them have exactly one of those issues (it's never both). I'm currently back on ATT stock 4.4.4 ROM (3.42.502.1 firmware), rooted, S-Off.

I thought flashing the WWE RUU before flashing a ROM like ARHD would be enough to upgrade the firmware, but maybe I'm missing something.

WWE RUU indeed updates the firmware, however to the WWE radio and other firmware.

I think a couple things are going on here (assuming your are on AT&T's network):

1) A number of folks have reported call issues while on AT&T's LTE network and running WWE based custom ROMs. The suspicion is that the changes being made by AT&T in advance of HD Voice (Voice over LTE) deployment is not playing well with Euro based ROMs. AFAIK, there doesn't seem to be a fix for this, although I think some devs like Team Viper are looking into it.

2) US Dev Edition is intended to be used on AT&T's network. However, its not clear from your description, but it seems you are using the WWE firmware (radio probably most importantly) with the Dev Ed ROM. If you haven't already, try the Dev Edition firmware with the Dev Ed ROM; either by RUU or flashing the firmware separately. That is the configuration I was running until just last week (giving Sense 7 a try) and seemed to have no issues on AT&T, including travel to a couple different locations around the country.

 

[Double_a2013]

WWE RUU indeed updates the firmware, however to the WWE radio and other firmware.

I think a couple things are going on here (assuming your are on AT&T's network):

1) A number of folks have reported call issues while on AT&T's LTE network and running WWE based custom ROMs. The suspicion is that the changes being made by AT&T in advance of HD Voice (Voice over LTE) deployment is not playing well with Euro based ROMs. AFAIK, there doesn't seem to be a fix for this, although I think some devs like Team Viper are looking into it.

2) US Dev Edition is intended to be used on AT&T's network. However, its not clear from your description, but it seems you are using the WWE firmware (radio probably most importantly) with the Dev Ed ROM. If you haven't already, try the Dev Edition firmware with the Dev Ed ROM; either by RUU or flashing the firmware separately. That is the configuration I was running until just last week (giving Sense 7 a try) and seemed to have no issues on AT&T, including travel to a couple different locations around the country.

Yeah, I'm on AT&T's network. So I should just download the dev edition ROM from HTC's website and RUU it?

 

[redpoint73]

Yeah, I'm on AT&T's network. So I should just download the dev edition ROM from HTC's website and RUU it?

If you don't mind wiping the phone (backup any personal data that you want to keep before RUU, obviously), then yes that is probably the easiest way to do it.

 

[Double_a2013]

If you don't mind wiping the phone (backup any personal data that you want to keep before RUU, obviously), then yes that is probably the easiest way to do it.

I just did; LTE is working, but I can't receive calls. When someone calls me, it goes directly to voice mail without ringing

EDIT:

So I actually got a call to come through. When it did, LTE went away and wouldn't comeback, so it definitely seems like an issue of VoLTE compatibility, even on the Dev Edition ROM for me.

 

[redpoint73]

I just did; LTE is working, but I can't receive calls. When someone calls me, it goes directly to voice mail without ringing

EDIT:

So I actually got a call to come through. When it did, LTE went away and wouldn't comeback, so it definitely seems like an issue of VoLTE compatibility, even on the Dev Edition ROM for me.

Weird. I wouldn't think that you would have the issue on Dev Edition ROM, running Dev Edition firmware.

Can you confirm the RUU properly installed the Dev Ed radio, by stating your radio number?

Forgot to mention that turning off LTE is a workaround. But obviously less than ideal.

 

[Double_a2013]

Weird. I wouldn't think that you would have the issue on Dev Edition ROM, running Dev Edition firmware.

Can you confirm the RUU properly installed the Dev Ed radio, by stating your radio number?

Forgot to mention that turning off LTE is a workaround. But obviously less than ideal.

The radio that was installed was 1.24.21331147A1.09G_20.68.4196.01_F

 

[redpoint73]

The radio that was installed was 1.24.21331147A1.09G_20.68.4196.01_F

I confirm that is the correct US Dev Edition radio baseband.

Weird, I've used mine (as mentioned) not only in my home area of Boston (and surrounding areas) but also while travelling to North Texas, and Washington State, and didn't see any issues. But that is by no means exhaustive. We really have little way of knowing what changes AT&T is making to their LTE network and where (in preparation for HD Voice).

You might fall back to the AT&T 4.4.4 ROM (and even the corresponding radio) to see what will happen. But that's of course kind of disappointing to fall back to KitKat from Lollipop.

You can even try the WWE firmware (4.16.401) zip. But I'd be very surprised if you get a better result on the WWE radio versus the Dev Edition.