Database Develop

dropped calls

Does anyone have the same problems with the breeze that when you make a call it can drop it with no warning show "No service" and suddenly get it back straight away?
i have radio 1.38 installed, using a ORange UK 3G PAYG sim in a full coverage 2G area and 1-2 bars 3G area.
i have tried to set the thing to GSM only and 3G only but this doesn't solve it. has anyone......anyone out there figured a way to sort this?
or does anyone know of the possibility of getting a replacement from HTC that works?
cheers to anyone who can help
Dan

Same problem here, with Orange also, although on contract with them.
Please let me know if you find a solution. I emailed HTC, which I already know you have done, and you have had a replacement handset. This is not a good start for me
I had the best luck with my Sony Ericsson K610i. It was the best 3G Bluetooth Modem ever.. shame no Exchange ActiveSync/DirectPush

I have exactly same problem. Phone calls are dropped with no services message. And I have to restart phone at least once a week because my phone will fail to find any network. After reboot it works fine for a while. I have latest firmware with 1.38 radio. Phone is from O2 CZ.

Hi guys,
did you try to switch from 2G and 3G connection to 2G only? I assume this problem is caused by the network coverage while the Breeze is switching from 3G to 2G and vice versa. Me and some friends (Vodafone and T-Mobil) didn't discover these kind of problems.....
Cheers
Michael

Yes, I did it. But I still have to restart phone every week because phone lost signal.
I'm thinking about to flashing newer radio.

Hmm, we are using this version: "MTeoR_Upgrade_1.34.251.1_1.38.00.10_EUR_SHIP.exe" and it works well......

Problem with internet Communication

Hello All,
I have a problem with my kaiser, it started i think 2 weeks ago. I have vodafone (netherlands) with a data connection account (hsdpa). Now is the problem that i can't use umts (3g) or hspda. The only thing i can use is gprs. It looks like the modem or something is broken. But that is a kind of weird because (if i understand correctly) its al the same chip (wifi and so on). When i open internet explorer it begins to connect a gprs, 3g data connection. But it can't connect, than you can see a X by the synchronisation arrows (on the top of the screen). And after a few secconds it comes with a message that with the current settings there can't be a data connection. But if seen other messages as well ( the modem on the other side disconnected the connection) The weird thing is that i tried my sim card in my friends kaiser there it works fine, so it have to be my kaiser.
Ok what i tried:
I have a dutch htc kaiser (not vodafone branded or anything)
I use the latest dutty rom, but i tried the orriginal rom and different roms to see if the problem was the rom or something.
When i let the 3g mode on i can see that the phone finds a 3g connection (to call over umts).
Is there any program or tool or something so i can test the modem?
Or does anyone know a sollution for me, i will be very greatfull!!

Ok i tried a other radio to, maybe this was the problem. But it didn't, at this moment i have the default htc dutch rom (who was on the phone when i got it). I searched the net for the same problems, what i found was that this error could be happening when you have your wifi connection open, but i have wifi disabled. The phone is still receiving a 3G connection, but after a few secconds the 3G icon is gone and the failed synchronisation icon (two arrows with an X) is visible. than you can see that the phone is reconnecting. and then if i want to connect to the internet the same story as above is happening.
When i search internet i couldn't find an tool to test the chip/modem.
Because i have it spl unlocked i can't return it for rma, is it posible to restore the default spl?

Hi,
unfortunately I have the same problem with my Kaiser. I have an unbranded German version and it worked fine with all bands (GPRS, EDGE, UMTS(3G) and HSDPA) but since two weeks ago its only working with GPRS and EDGE mode. I have to change band-selection from AUTO to GSM in order to make or receive any calls.
I didn't do any ROM flashing, everything remains the same as the device was shipped.
I assume, that something is damaged but I have no idea how it could happen or how I can find out exactly what is causing the problem.
Since there is still warranty I'll return my Kaiser soon.

seems to be a widening problem
hi,
it seems many have the same issue, see my other posts for linkage to some other threads on it...no solution yet as far as I can tell.
rich
p.s. moderators any chance to link these threads and make a sticky?

ok, thanks for your reply. I've allready found another thread for that issue. But im still uncertain if its a bug in my device or a combination of a bug with a provider specific (Tmob Germany) problem or if its only the provider to blame for??
Chris

I have a slightly different problem. I don't have 3G in my area but only EDGE. Now the problem is that I cannot get speeds higher than about 80 kbs with EDGE.
Now when I put the same SIM in my Touch I can get speeds upto 200 kbs. So obviously this is not a problem of my service provider but rather something wrong with the device.
I have repeated the trial by swapping SIMs a number of times but with similar results all the time. Really don't know of a solution. Will appreciate any help.

haven't seen the edge problem
hi,
my edge speeds seem to vary more by location...I measure up to 200+kbs but have seen it go much lower too. there is a location where I can still get 3G working and i measured up to 1.7mbs for downloading! At my home location it is sporadic edge only and I can't even always get to speakeasy.com to test it, sometimes the speedtest says its not licensed..switching to wifi and it works. My guess is some needed ports are getting blocked by at&t at times..because sometimes it works. I brought all this up with at&t..they are taking some charges off this month and switched me to a cheaper plan too...so they at least seem to care even if they can't quite fix things yet.
rich

my Kaiser do not work with 3G only works on GSM

Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!

nunu said:
Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!
Click to expand...
Click to collapse
Might kinda help to tell folks where you live. Country? State/province?

UK,London
thnx for your reply i live in London,United Kingdom

Signal lost, this might help...
nunu said:
Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!
Click to expand...
Click to collapse
Hi there nunu,
I had the same problem, went back to the store and nope not a known problem.... So I started to troubleshoot this
1. normal G connection
2. 3G appears or even H
3. signal lost and after 30 sec. the cycle starts again.
what worked for me was the changing the of the radio version. I am currently in the Netherlands and here the NEON_Radinly_1.65.24.36 works fine, I confirmed it by loading a rom with a different radio in it and the result was again the same.
hope this helped in any way...
Let me (us) know.
-------------------------------------------------------------------
life is good, but life get's much better with a Kaiser

are you trying to connect with [email protected] / cingular1 ?
this is the kinda information you should have put in your first post
I use the above and have zero problems in Philadelphia

My 3G went out for like a day here (Phone only worked on Edge), then it started working again. Cellular carriers do have outages from time to time. Has it been a long while since it stopped working?

nunu said:
Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!
Click to expand...
Click to collapse
Flash to a different compatible radio. If you do not get 3G/H service back, then you have a hardware issue with your radio, and will need to have the phone serviced.

what newtwork are you on?
have you tried your sim in a different handset?
what happens when running in gsm only mode?
in settings phone network change selection to manual and tap find networks and reselect network (this is known as a manual roam) does this make a difference?

Same here!, im in montreal, canada with Rogers, and in 3g doesnt work, it detects the 3G network, but as soon as i try to make a call or go on the internet it looses the signal and i have to go on GSM mode.
and i'm using LKDV12 but i still had the same problem on AT&T Original rom, and Dual V2.
Anyone?

Major problem --
I have been travelling round the world for a year and have the same problem, Have tried many radios, if I use 3G( wscdma) or auto band then the signal drops everytime i try to make a call, and no data is possible however if I use gsm only data and voice work fine, thease symptoms are on many networks, Chile, Easter Island,Tahiti, NZ, Fiji, Optus ( OZ ), and m1 ( singapore ),
Radios tried
EMO 1.71.09.01
Neon 1.65.24.36
1.65.21.18 ( att )
I even loaded the generic dopod rom + radio and it didnt seem to help.
Is it possible something low level has changed whilst doing all this flashing ?
Or could the Hard SPL affect something.
I always try to buy a 3G USIM in each country and test the sim in a backup G800 to ensure the carrier has enabled 3g data okay.
Phone is Kaiser ( HTC TytnII )
ROM is varied but and usually lorentis series roms -- L26 12 light atm
Symptoms, 3G icon shows but data wont connect, if you try to call radio strength bar drops to zero and cell communications are lost , sometimes reestablishes comms but often needs soft reset to band switch to work.
If 3G icon not showing all calls and GPRS data works Okay.
Personally I would not expect this to be a hardware failiure as many others are experiencing teh same fault and for working hardware to fail in use is more erratic in the failiure mode, but a low level register, or some other type of protocol corruption could easiliy be the cause......
The proven "high GPS current consumption in standby" issue is also present as it seems to be on all Kaisers but afaik the root cause of this was never resolved either .....

my Kaiser do not work with 3G only works on GSM NEED HELP
HI I´m from mexico telcel gsm band and the same problm works on my kaiser tried changing the rom put the htc rom again the radio too
settingsROM 1.62.502.0 WINDOWS MOBILE 6 BUILD 1828.0.4.4
RADIO 1.27.14.09
PROTOCOL 22.45.88.07H
by the way how can i make it work on gsm only or edge or other than 3g that doesn't work
tks for your assistance iñm getting frustrated
edge

nunu said:
Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!
Click to expand...
Click to collapse
i have the same problem did you make it work how you set a gsm band instead of the 3g on the phone tks for your assis
dr.vogel

I have the same problem. Already had it with WM6.0 original HTC ROM (Finnish ROM, but language set to English). Then sent it to service. It came back, they said they "reapplied software or smth" and it worked after that. Then after 6.1 update again, the same problem (even with the latest updated Radio ROM).
When I set band selection to auto, it picks up 3G or even H but tends to loose it and definetly looses connection to network if I try to make a call. Can't take any incoming calls either.
It works ok when I force it to use GSM (EDGE for data) on Band selection tab, in phone properties.
I probably won't bother taking it to service anymore cause there is no local service here in Estonia, they ship it to Finland and it will take a minimum of 3 weeks...
... so I'm waiting for Xperia X1 and hope it's not as much HTC.

nunu said:
Suddenly it had happened; NO 3G nor GPRS data transmission. I can see the 3G sign , but when I make calls the phone disconnects; when somebody call me, he received a message that my phone is off line. Only when 3G signal is on. But when normal GSM is on, everything will be OK. My phone can not get data from the internet, even though it shows that is is connected. I tried all of the above solutions to fix this problem but no helpand sometimes it shows 3g sign but as soon as i try to call some1 all the signals are gone.. I tried to hard reset and try it before installing any software, no help. I tried mostly all available ROMs and Radio ROMs; even the original, but not fixed. I do not what to do. Now, I am using the phone with GSM only, NO 3G. Please help!!!
Click to expand...
Click to collapse
Read this: http://forum.xda-developers.com/showthread.php?t=335074
Hardware problem, repair needed and unavoidable to get 3G functionality back.

I have the same problem.
I bought an O2 Stellar (Kaiser) from a work colleague and it worked fine on 3G/Auto on the day I bought it.
The next morning, when I switched on the phone, it had exactly the symptoms described (i.e. it would only work if forced into GSM mode).
My colleague took it back to O2 under warranty.
1 week later, it was returned as 'fixed', but it actually still had the problem, so my colleague returned it again to O2.
Another week later, O2 provided a replacement unit under warranty.
The replacement worked fine, until the next morning when I turned on the phone and had to force it into GSM mode again because it wouldn't work in 3G/Auto mode.
I'm on 3 in the UK and I suspect the problem is something to do with the roaming onto Orange GSM which happens when there is no 3G signal from 3UK. However, on the day each of the units worked, it was switching between 3G and GSM repeatedly because the 3G signal is fairly poor in my office.
I'm now waiting for my colleague to return from his holiday so that he can return this unit to O2 and we'll see if we get another replacement. If we do, I'm very reluctant to actually use it - I think I'll probably just sell it on and get something different. Shame because I really like the Kaiser.

as mentioned before, another thing that you should've tried is to call the helpline and see if there's an outage in your area. I've been experiencing the same problem in a very particular area (3G hand-off to EDGE problem only happens on campus). Tried different radios and problem still exist, so I gave them a call today and turned out that there is an outage here.

In my case, it's not caused by a network outage - 3G works fine on my Hermes in the same locations.
Good thought though.

Relax boys...I have'd the same problem... The only solution is to go with your phone for warranty return. There they will change your TyTN II mother board and all will be ok. IT IS THE ONLY WAY.
PS do the same thing I did http://forum.xda-developers.com/showthread.php?t=418375

i post this thead and the solution
i post this tread an the solution came on tha answer of various of you great ideas i get the solution changing the rom and the wm to 6.1 and the rom is the dutty's it has worked almost perfectly in any wy itested only some install on the gps progrms but no mayor problem tks all you friens for a great support

The same thing has happened to me as well (Orange UK).
Initially I thought that it was an outage in my area as my friends had problems connecting to 3G as well, but their problem has been fixed but I still cannot.
I'll be contacting their tech support dept. later today and I'll post back.

[Q] 3G- no data, but GPRS, Edge & HSDPA ok?

I've had this problem with my Nexus One for as long as I could remember, but kinda ignored it - thought perhaps a new radio would fix it, or a new ROM...
But no, it still bugs me.
Basically, if the phone is on 'normal' 3G, I cannot receive any data. It just gets no connection. If I have HSDPA, or GPRS or EDGE - it all works fine.
But 3G? Nothing. And its EVERY time.
Travelling on the train every day, HSDPA isn't stable, so it often drops to 3G, but then it drops dead. I have to restrict the phone to 2G if I want to check things reliably.
I've tried every radio from every country from the original to the latest 5.12 leak.. yes, speeds increase, HSDPA engages more often, but as soon as I'm on normal 3G: Dead.
And I've tried all ROMs (original, MCR, Cyanogen, Desire, MIUI) - same.
Any build.prop tweaks I could find... same.
Now, I remember talks about this when the Nexus came out originally - but there doesn't seem to be any threads about it now, so do I just have a faulty Nexus One that I've put up with since Christmas last year?
Or have I missed something blatantly obvious that every else did to fix this problem?
Any help gratefully received

Pardon my grammar and spelling I'm typing from my phone without swype and its annoying. I had a similar problem. When on 3g I'd miss calls texts, etc...I had my boss call in my face and my phone didn't ring. It got so frustrating I turned off 3g for several months. Too make a long story short ....all those 3g problems went away when I 2.2 came out on xda I put a new radio and rom on. I can't tell u if it was the radio, 2.2, or if tmo had simply added new towers or improved signals from tmobile.
I'd call tmo see how your area looks and if there's any new towers.

I've been on 2.2.1, and 2.1, 2.2, and used all the radios that have been released.
All the same.
I'm in the UK and on Orange, and I have spoken, well, tried to speak to my network about it a couple of times, saying the fact that I've had this issue in the past with my HTC Hero, and I've tried every software update, radio, etc, but because the Nexus One isn't an Orange handset they blame that, Android, or the signal in my area. Yet, I can't believe its just 'Android', and it can't be all signal where-ever I go, so perhaps my phone does have a fault? I don't know!!
The common denominator between this and my Hero is the SIM card.. but convincing them the SIM is faulty is nigh impossible. I'm receiving calls and texts on 3G, and get data all the other times, so it can't be... can it?
Argh, as you can see, this is slowly driving me mad..!!!

Yours sound worst than mine. I used to have very reliable 3G data until upto mid October. After that period, there were numerous reports of Orange UK users struggling with data blaming (with high possibility) on merge plan with T-Mobile.
I tried SIM with my Hero and Nokia N82. All 3 phones suffer the same poor 3G connection and in places I spend my time mostly, all struggle to get any form of internet. Few months back on same places, all my mates were impressed by Orange's coverage.
Yesterday, out of nowhere I received a sms from Orange confirming that merged plan went well and customers are to benefit from all cell towers of both network. Couldn't stop smiling then tried to access XDA on N1's browser. Safeguard was ON and access denied. Tried to open few more, all same. Frustrated almost dialed 150 but couple hours later, all started as normal with H signal. No interruptions, no waitings and no error msg. Tested for almost 8 hours. Though still to confirm the reliability.
One more thing I noticed is that before I was using WM's AVS kernel. Almost always once in every 4 attempts, a msg would pop up on error connecting. Changed to SVS kernel and msg still would appear but very very rare. BTW, on latest Nightly.
Coming to end with orange contract and if problem continues, I'm moving to O2.
Try your SIM on other phones to see whether it's the issue with N1.

I might have the same problem. but this just came up 2 nights ago. while connected on data network, all is fine until it drops to 3G, app (opera mini) freezes and you will have to force close. restricted my network to 2G and all was fine. then a while ago i enabled again on 3G and all was fine again.
is this a sign that i may get your same problem soon?

[Q] Help! D5803 on AT&T - not receiving text messages or calls

My new xperia z3 compact (D5803) receives text messages and calls very intermittently. I'm on AT&T US, stock firmware.
- If I am using the phone (or have very recently used the phone, say within 30 seconds) then most calls and text messages come through fine (though not always).
- If I leave the phone alone for more than a few minutes, text messages or calls almost never come through - though occasionally I get a text message many hours after it was sent.
- If someone leaves a voicemail (because I didn't answer the phone, because the phone didn't ring!), I don't get a notification until I open the voicemail app and manually sync.
- I can make a phone call or send a text message with no problems (texts arrive immediately).
I don't have any of these problems when I put my SIM back into my HTC One M8.
I've tried the following to fix this:
- I went to the AT&T store and had them give me a new nano SIM. It made no difference; same issues.
- I factory reset my phone. It made no difference; same issues.
- I updated to the US version of the firmware. It made no difference; same issues.
- I put the SIM into a second, until that point unused, xperia z3. It made no difference; same issues.
Given that I have exactly the same issues after changing both the SIM and the phone, I can only think it must be some kind of compatibility issue with using AT&T on this phone - except I see that many other users of this forum are on AT&T and aren't having the same problems.
I do notice that I don't have the best signal in my house (usually 1-2 bars) so I'm wondering if maybe that could be related? As I say though, my HTC One works fine, as do all of the other AT&T phones in my house.
I think my next step will be to go and buy a T-Mobile prepaid SIM, just to see if that works, but does anyone have any thoughts or suggestions? All in all this is getting pretty frustrating, because I LOVE the phone, but right now it's unusable for me.

I would suggest reading this thread below. It should give you some tips on how to resolve your issue.
http://forum.xda-developers.com/z3-compact/help/att-apn-settings-lte-t2888644

Thank you for trying to help!
I probably should have added that link as one of the things I had already tried. To be specific, my APN settings are:
Name ATT Phone
APN phone
Proxy Not set
Port Not set
Username Not set
Password Not set
Server Not set
MMSC http: //mmsc.mobile.att.net
MMS proxy proxy.mobile.att.net
MMS port 80
MCC 310
MNC 410
Authentication Type None
APN type default,mms,supl,hipri
APN protocol IPv4
Bearer Unspecified
---------------------------------
I'm beginning to think it *must* be a signal issue, even though all the other phones in my house are fine. I have the "Advanced Signal Status" app installed, but I'm not sure what I should be looking for to see if there's anything fishy

Don't forget to download the Internet and MMS settings for your phone. You go into Settings > Wireless & Networks > More > Internet settings and download settings for Internet and MMS

Thanks again for the suggestions.
Sadly, it's still not working. I'm pretty sure I had already downloaded those settings, but I did it again anyway (seems you can just download over and over). I even reset the phone after that just to be sure, but the problem persists.

I have the same issue and I live in Sweden....

Im having the same issues. I restart the device and then come all the missed calls and missed txt messages.. i really hope theres a easy fix to this soon.

So, I switched my SIM from AT&T to T-Mobile and it fixed my issues. It seems that the either the poor AT&T reception in my house or some other strange incompatibility between the phone and AT&T was the problem.
Either way there's obviously some kind of issue with this phone - my guess is that when connectivity with the network is poor, the phone maybe times-out and gives up. Perhaps Sony will fix this with a firmware update at some point. In the mean time I would suggest that other folks having this issue maybe go to a part of town where they know reception is very good and see if the problems happen there.

So after 2 days of of testing, a new nano sim card and several phone calls to ATT I found temporary fix. Change your Network mode to WCDMA (preffered)/GSM. While this wont give you LTE it will prevent the missed phone calls and txt messages and at least you have HSPA+ . The problem is the LTE connection to ATT. The connection either drops and or prevents phone calls /texts from coming through the lower HSPA + or 2g bands... Not sure why this is. Hoping that when the Sony Store models start shipping on Nov 2nd they have the same issue and Sony will send out an update to fix the connection issue.

I'm on the US ATT network with the same problem as well. After trouble shooting I have come to agree with you. I'm really hoping Sony sends out an update.

Is this a problem on Tmobile USA with Z3 Compact also?

same issues!
I have two Z3 compacts (US version purchased direct from Sony) on my family plan with the same issues of not receiving SMS or calls when connected to wi-fi, and occasionally cannot receive SMS or calls when not connected to wi-fi either. I am always able to send texts and calls, and MMS/LTE always work (I am usually e-mailed when my phone isn't working and I get that right away). Whenever the phones aren't receiving calls, it rings once and goes to voicemail, which tips us off that the phones aren't working.
If you are also getting this problem, please get on AT&T chat and ask them to escalate/forward to their manager. We've got to get their attention. Additionally, I was told that "Okay so since the phone is unlocked our service is not guaranteed to work at full capacity, also I can not submit a case due to it is not an at&t phone. "

Yep - Same problem over here. AT&T in Northeast USA.
AT&T tried everything they could (resettings connection, etc) but again also said that it isn't guaranteed to work because it's an unlocked device.
I'm doing a system repair on the phone from the sony desktop application. Hoping it will fix, but not hopeful. Now sony says they want to have my phone in for testing. :/
I'm hoping they realize soon that this is a bug, and not a case of a broken phone.

Same problem here on cricket (AT&T) in Houston. Just disabled LTE. We'll see if that fixes it like it did for the other guy. Sony needs to get on this.
Sent from my Nexus 5

Not working MMS
Yep I have tried all of the above solutions and nothing is working. Changed APN multiple times, factory reset, switched SIM, called att, went into the store.
Like above, ATT came to the conclusion that unlocked phones are sometimes not compatible with their service and there's only so much trouble shooting they can do.
I have ATT in san francisco, and it's looking like I'm going to return the Xperia z3c. Shame it's a great phone besides the MMS issue.

aaronv20 said:
So after 2 days of of testing, a new nano sim card and several phone calls to ATT I found temporary fix. Change your Network mode to WCDMA (preffered)/GSM. While this wont give you LTE it will prevent the missed phone calls and txt messages and at least you have HSPA+ . The problem is the LTE connection to ATT. The connection either drops and or prevents phone calls /texts from coming through the lower HSPA + or 2g bands... Not sure why this is. Hoping that when the Sony Store models start shipping on Nov 2nd they have the same issue and Sony will send out an update to fix the connection issue.
Click to expand...
Click to collapse
Confirmed that this worked on my wife's z3c. She wont miss the LTE anyway since she is always near wifi and when she isn't 3G is definitely good enough. We streamed spotify for an hour today on country roads on her phone on 3G. No issues.
Sent from my Nexus 5

sorry to hear you guys are having such issues...
My z3 compact on att works flawlessly. I swapped my nano sim from a iphone 6 i was trying out straight into this.
Att did mention something about some settings they had to flip in the back end when i switched over to a nano sim from the sim i was using in my lg g3. If you guys loose all hope have a buddy with an iphone on att and use his imei and let att configure the sim for that phone then swap the sim into the z3...could work because i know it does for me

Same issues here. I have a new D5803 on Straight Talk (AT&T). I live in the mid Atlantic. It seems I don't receive calls/texts when I have 2 bars or less. Not sure about LTE vs. HSPA. I always have Wifi on so not sure if turning it off would make a difference. THIS IS A HUGE ISSUE! Hopefully a firmware update will save us. Has anyone contacted Sony?

mtilson said:
Same issues here. I have a new D5803 on Straight Talk (AT&T). I live in the mid Atlantic. It seems I don't receive calls/texts when I have 2 bars or less. Not sure about LTE vs. HSPA. I always have Wifi on so not sure if turning it off would make a difference. THIS IS A HUGE ISSUE! Hopefully a firmware update will save us. Has anyone contacted Sony?
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Yes it does make a difference. Turn it off and everything should work.
Sent from my Nexus 5

sublimnl said:
Yes it does make a difference. Turn it off and everything should work.
Sent from my Nexus 5
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Thanks for the info, but this isn't a viable solution! I shouldn't have to keep Wifi off to ensure I receive my calls/texts!