ALERT !!! Serious problem with 4G/LTE to 3G/GSM switching.

[stefan_c]

It must be a serius bug !!!!

I have made an very deep investigation on this problem and it seems that the new software (Oreo Android 😎 has messed up the 4G/LTE to 3G handling/switching quite a bit.

When 4G or 4G+ with weak signal is locked to the phone and you start a call, the mobile network in our country at least (Tele2) reroute the call to a 3G/GSM system, and it fails every time. But if I disable the 4G to 3G,GSM the call works EVERY TIME. Note, you cannot even be reach as the network just drops the call, doesn't find the phone, but on 3G/GSM it works flawlessly.

I'ved put the simcard in my Lumia 900, no problem at all, put it in a Samsung , same here no problem at all. But my Wifes XZP with same software has the same problem, her work phone (Samsung)  with the same operator on the same test location (spot) doesn't.

The testing is with all the phones is done att the same spot, at different spot / locations with same result specially on weak 4G signals. I use the app Network Cell info to actually see the problem with 4G to 3G switchover, so the problem is definitly here.

So.   SONY YOU HAVE TO FIX THIS NOW, NOT IN ABOUT 2 WEEKS OR NEXT PATCH,  JUST RIGHT NOW.

This is really, really bad engineering, and yes I'm a software programmer / tech on transmission systems with over 30 years of exp.  So Sony here me out , the Android 8 has serious problem with XZP and 4G/3G handling.

// Stefan

[Lennyxz]

Thanks Stefan, seems to be major problems in the Oreo code. That problem you describe is very worrying. I have just posted about a very closely related wifi / mobile data handover bug which I have been working on since the upgrade to Oreo.

SONY YOU NEED TO GET ON THIS QUICKLY. 

[stefan_c]

Thanks for your reply, your described problem feels like it narrows the 4G, 3G problem as the handover to 3G is made by tcp/ip. 

[Lennyxz]

Thanks Stefan, yeah there is some glitch in the networking handovers between wifi and mobile data and possibly within mobile data too. I have logged with Sony in detail, been through about 5/6 emails of the usual frontline support 'turn it on turn it off' 'blame third party apps' 'blame google' 'reboot' 'software repair' etc etc and no joy. This is a software bug which Sony have to fix.  I have now escalated and waiting on a manager to call me which they say will happen in 2 - 3 days. Rapid support eh!!

[stanlykubrick]

If you Google the issue(s) with WiFi and 4G on Oreo you will find too many pages to list here. This is a Google problem! Now, whether Sony has the ability to fix this issue remains to be seen. But it is certainly an issue with Oreo. I personally do not have the problem. That is what makes Android BUGS so troublesome. Why do some people have all these issues while the majority do not? The only possible explanation to me is one of two things....either the hardware on these phones is not all the same leading to a possible driver issue, or there is a third party app installed on the phones that is causing the issue.

If we have two phones with the EXACT same hardware AND the exact same software...top-to-bottom-start-to-finish...then both should work exactly the same way. There has to be "something" different from one phone to the other to causer these issue for some and not others.

I just wish that Google would STOP making new versions of Android every year and FIX the ones we are already using so that these expensive tools, that we rely on every day, work as advertised/expected!

[stefan_c]

Yepp, my wifes XZP is from the same "batch", we have the same problem. 

I seriously doubt that a third party app has the rights to fiddle with 4G,3G routing as this function is a system/core function. Yes,  I know that Sony is not to blame here, BUT if your car have bad brakes, do you complain to the car manufacturer, reseller  or the company that makes the brakesystem.....

/S

[NEsan]

I have the same! 

[Andyben]

No, not an Oreo problem, its a XZP problem.

Since i bought mine I've been unable to use 4G for any length of tme as as soon as the signal weakens it drops out to zero bars and won't switch to 3G without prompting.

I think that Sony put 4G performance/speed  over reliability as the gigabit LTE modem is a bit of a waste.

Would rather have had a slower max speed (which is unacheivable in most instances) but with a more reliable signal

Saying that, 3G is fine in most instances even streaming Amazon/Netflix with no issues and i would rarely need the additional speed while not at home or in the office - which i guess proves my point further

[RuneJ]

4G works fine on XZP. 

VoLTE supported by carrier and enabled, XZP switches nicely to 3G when 4G drops off during a call.

[stanlykubrick]

First of all...it IS an Oreo problem...do some research...Google it. (Ironic no?)

The bars in the notification area mean nothing, they can be manipulated easily by the OEM.

What is the SIgnal strength...the dBm?

In a tall building in Houston I can have zero bars and my 4G still functions just fine at 111 dBm.

Now 111 dBm smells up the room but that has nothing to do with Sony....maybe T-Mobile can be faulted and that is why they are trying to get their new 600 MHz spectrum rolled out as it will penetrate better into buildings and your brain! LOL

When I make or receive a call my signal drops to 3G as expected and returns to 4G when I hang up.

Have you tried a software repair using the Xperia Companion on your PC?

It will factory reset your phone but with ALL NEW software which is better than doing a standard factory reset from within the phone itself. Maybe this will help???

Other than that we will have to get on Google to FIX their buggy OS and get it out to us as soon as possible.