Database Users

[Q] Nexus 4 loses network connection when enabling data over mobile network

Hi there,
my new Nexus 4 loses its network connection every time I enable data over mobile network. It's like a loop - I have to enter the PIN, then it searches for the network - some times it finds one and connects and then it loses it again. I tested this with two different micro sims from Hutchinson 3G Austria.
I also looked at the logcat output:
01-04 06:51:04.315 E/QMI_FW (173): QMUXD: Service_id=24 not found over conn_id=0
01-04 06:50:54.775 W/Netd (159): No subsystem found in netlink event
01-04 06:50:54.775 D/NetlinkEvent(159): Unexpected netlink message. type=0x11
01-04 06:50:55.305 E/kickstart-efsks(8496): File '/dev/ttyUSB0' was not found
01-04 06:50:55.305 E/kickstart-efsks(8496): /dev/ttyUSB0 does not exist.
01-04 06:50:53.283 E/kickstart(8706): ERROR: function: connect_and_configure_device:332 Not Connected to the device: /dev/ttyUSB0, Linux System Error:No such file or directory
Should I return it, or do you think that this is a software issue?
You can also find a full logcat dump attached!
Thanks for your help,
Roman

I am having this issue also. I am on T-mobile network in US and 3G,4G data was working fine when I got the phone end of Nov and after a little over a week, there was data connectivity issues and it wouldn't have data connection at all but I can still make calls and text. I am testing now and when I turn on 2G only, there is reliable data connectivity and internet is back on but of course slow 2G speed and when I turn off 2G and go back to 3G,4G connection, data connection fails. I have tried everything from restarting phone, turning mobile data on/off, resetting APN to default and restarting phone but 3G/4G data is not working fine at all but if I switch on 2G, it works fine and I don't even need to restart phone. Now, when I test it with another service carrier micro sim from AT&T, it works flawlessly and fast on it's 4G speed without any disruption. Conclusion I have come up with is, there is definitely a 3G/4G data connectivity problem with T-mobile and my Nexus 4. Maybe T-mobile is updating 4G networks and there's connectivity issues with our devices and they don't even know it. Please let me know if anyone else is having this problem. Thanks

I have a similar issue. On screen wake up my device asks for SIM PIN code as if the device was either restarted or the sim card was unplugged/removed and reinserted again. This has happend five-seven times the last seven days.
I dont think the device has been restarting it self. I think that it loses signal and the device some how thinks that the sim pin is then required agian when it find the signal...
Verry strange.
Service provider; Halebop/TeliaSonera (SWEDEN)
Deivec: Nexus 4
ROM: CM 10.1

So you have signal issue and do you lose data? Today I did some more testing. I was at a another city about 70 miles from where I live and voila, I got 3G/4G data connection again, where as I wasn't getting at all where I live and I have switch to 2G data to even get data connection. So, there has to be 3G/4G network connectivity issues in certain places due to settings from carriers with our Nexus 4. I'm using T-mobile in the US. I called T-mobile and reported the issue and it will take about 3 days for their engineers to look into it. Are others having this issue?
Kaherdin said:
I have a similar issue. On screen wake up my device asks for SIM PIN code as if the device was either restarted or the sim card was unplugged/removed and reinserted again. This has happend five-seven times the last seven days.
I dont think the device has been restarting it self. I think that it loses signal and the device some how thinks that the sim pin is then required agian when it find the signal...
Verry strange.
Service provider; Halebop/TeliaSonera (SWEDEN)
Deivec: Nexus 4
ROM: CM 10.1
Click to expand...
Click to collapse

Sorry to resurrect an old thread -- OP, if you're reading, did you ever figure out what the issue was? I'm having this exact issue as of a day or two ago.
It used to be my Nexus 4 would ask me to "sign into T-Mobile" every so often. Now it asks me constantly and when I do, it goes to a T-Mobile web page saying, "according to our records, you do not have data service." I called T-Mobile and they said everything looks OK on their end.
All I can do is phone and texts. No Google services (I needed the GPS this morning -- that was fun).
Reset from 10.1CM to default factory image, same thing.

OnePlus Two - HSPA+ and 3G Data Connection Problem

Hi Everyone,
I'm usually just a reader on XDA, but I have found a problem that appears not to have been solved and wondered if anyone had any insight.
Problem Summary
When in an area (or network) with only HSPA and UMTS (strong HSPA/UMTS signal, but with no LTE or 2G available), the phone will drop from H+ to 3G erratically, always dropping the data connection. Traditional phone calls are not affected.
Detailed Description
I have a OnePlus Two and have 2 SIM cards. My first SIM Card is with Bell Canada (Virgin), and the second SIM Card is with WIND Mobile Canada.
Neither Bell nor WIND operate a 2G network, so the lowest the service can fall to is UMTS/3G.
Initially, I didn't notice the problem because Bell also operates an LTE network, and there is no problem with dropping the data connections when on LTE.
When I switched to the WIND SIM card (which only operates HSPA and UMTS), I noticed a problem where the phone would initially connect to H+, begin downloading whatever is needed (say, streaming music), but then part way through the download, the connection would switch to 3G, and the data would effectively stop. Within a minute, the service would jump back to H+ and download some more, but this cycle would continue (H+ --> 3G --> H+ --> 3G... ), with no way of knowing 1) how long the H+ connection would last before dropping to 3G (usually less than 30 seconds), and 2) after dropping to 3G, how long before going back to H+. This problem makes the phone almost useless when there is no LTE.
The most obvious troubleshooting I did was move to locations of better signal but I quickly ruled that out, as nothing seems to remove this problem. Other things I tried was to: move locations in the city, reboot phone, hard reset phone, flash most updated version of Oxygen, unlock bootloader, root, try the HSPA Keepalive app, swap SIM1 to SIM2, and many other things.
I originally thought this was a network issue, but I put this WIND SIM in another phone and there was no problem in any way that resembled this problem.
I also ruled out this being a network-specific problem, as I have taken a trip with the Bell SIM to an area where Bell does not have any LTE coverage (only HSPA and UMTS) and the same problem occurs on Bell as with the WIND SIM.
I have found people who had this problem on the OnePlus One tend to recommend using 2G to stabilize the connection, but this is not possible on Bell or WIND. That solution also would not provide adequate data speeds.
Remember this problem only affects data connectivity, as 3G traditional phone calls have no problems.
Question
Does anyone know if there is a way to adjust the conditions when the OnePlus Two will choose to switch from H+ to 3G?
Does anyone have any easier suggestions?
Thank you all in advance, because this rendering this phone almost useless when there is no LTE coverage.

I believe your problem is that phone it's dualsim standby, that means only one modem that alternates signal for both sims, I think normal would be alternating from faster network to slower network on sim without data.
Having to change to g3 between sims theres something stoped in the modem and data connection is also stopped.
You have no problem with voice calls because other sim is automatically turned off and unreachable.
There's nothing you can do if you're forced to only 3g on both sims
By 3g I mean 3g or h+ which to my knowledge are the same
Hope I was helpful and not wrong or more confusing
Sent from my ONE A2005 using Tapatalk

fburgos said:
I believe your problem is that phone it's dualsim standby, that means only one modem that alternates signal for both sims, I think normal would be alternating from faster network to slower network on sim without data.
Having to change to g3 between sims theres something stoped in the modem and data connection is also stopped.
You have no problem with voice calls because other sim is automatically turned off and unreachable.
There's nothing you can do if you're forced to only 3g on both sims
By 3g I mean 3g or h+ which to my knowledge are the same
Hope I was helpful and not wrong or more confusing
Sent from my ONE A2005 using Tapatalk
Click to expand...
Click to collapse
Thanks, I will try disabling the second SIM to see if there is a bug with the dual-sim...
What it currently does with the second SIM is it either shows "R" for roaming or just emergency only, but perhaps there is a software issue so I'll see if disabling the second SIM makes a difference.

biomedeng said:
Thanks, I will try disabling the second SIM to see if there is a bug with the dual-sim...
What it currently does with the second SIM is it either shows "R" for roaming or just emergency only, but perhaps there is a software issue so I'll see if disabling the second SIM makes a difference.
Click to expand...
Click to collapse
Though strange, this workaround fixes the issue. Thank you to fburgos for the suggestion!
So just in case anyone ever finds this issue creeps up on them, the solution is to DISABLE the SIM you are not using. It's not the most convenient workaround to swap SIMs, but the other SIM will be in Emergency Mode, so it really makes no functional difference.
On the technical side, it does appear that there is actually a bug in Android for a very uncommon network configuration. It will only appear in this exact configuration:
SIM1: Network has HSPA/3G only, no LTE or 2G to move to
SIM2: Network also only has HSPA/3G with no LTE or 2G
The non-data SIM does NOT connect to a roaming network (connects with "Emergency Only") - if it connects to a roaming 2G network, this problem does not happen.
The data SIM connects to HSPA/3G
Both SIMs are active
I'm not sure if this will happen anywhere else in the world other than having a WIND Mobile Canada SIM and Bell or TELUS Canada SIM
If anyone has insight on how to report this to Google, or someone else who can confirm my theory, that would be great!

Try this:
1. You need to make sure you have the correct LTE APN selected in mobile networks and LTE as preferred type.
2. Go to dialer and type in this: *#*#4636#*#*
3. Phone Information
4. Set Preferred Network Type to: LTE/GSM (PRL) - you an play with which one you wanna use but the one I said works for sure. on other roms I have" TD-SCDMA, GSM/WCDMA and LTE"
5. Now click TURN OFF RADIO and wait WAIT few secs. will that button turns to Turn Radio ON
6. Now TURN ON RADIO and wait
7. when u see the triangle for the signal is back, at least black , go down and lick SMSC REFRESH then UPDATE.
8. now just go back to APN settings and go into your LTE APN
9. Change Bearer to LTE

biomedeng said:
Hi Everyone,
I'm usually just a reader on XDA, but I have found a problem that appears not to have been solved and wondered if anyone had any insight.
Problem Summary
When in an area (or network) with only HSPA and UMTS (strong HSPA/UMTS signal, but with no LTE or 2G available), the phone will drop from H+ to 3G erratically, always dropping the data connection. Traditional phone calls are not affected.
Detailed Description
I have a OnePlus Two and have 2 SIM cards. My first SIM Card is with Bell Canada (Virgin), and the second SIM Card is with WIND Mobile Canada.
Neither Bell nor WIND operate a 2G network, so the lowest the service can fall to is UMTS/3G.
Initially, I didn't notice the problem because Bell also operates an LTE network, and there is no problem with dropping the data connections when on LTE.
When I switched to the WIND SIM card (which only operates HSPA and UMTS), I noticed a problem where the phone would initially connect to H+, begin downloading whatever is needed (say, streaming music), but then part way through the download, the connection would switch to 3G, and the data would effectively stop. Within a minute, the service would jump back to H+ and download some more, but this cycle would continue (H+ --> 3G --> H+ --> 3G... ), with no way of knowing 1) how long the H+ connection would last before dropping to 3G (usually less than 30 seconds), and 2) after dropping to 3G, how long before going back to H+. This problem makes the phone almost useless when there is no LTE.
The most obvious troubleshooting I did was move to locations of better signal but I quickly ruled that out, as nothing seems to remove this problem. Other things I tried was to: move locations in the city, reboot phone, hard reset phone, flash most updated version of Oxygen, unlock bootloader, root, try the HSPA Keepalive app, swap SIM1 to SIM2, and many other things.
I originally thought this was a network issue, but I put this WIND SIM in another phone and there was no problem in any way that resembled this problem.
I also ruled out this being a network-specific problem, as I have taken a trip with the Bell SIM to an area where Bell does not have any LTE coverage (only HSPA and UMTS) and the same problem occurs on Bell as with the WIND SIM.
I have found people who had this problem on the OnePlus One tend to recommend using 2G to stabilize the connection, but this is not possible on Bell or WIND. That solution also would not provide adequate data speeds.
Remember this problem only affects data connectivity, as 3G traditional phone calls have no problems.
Question
Does anyone know if there is a way to adjust the conditions when the OnePlus Two will choose to switch from H+ to 3G?
Does anyone have any easier suggestions?
Thank you all in advance, because this rendering this phone almost useless when there is no LTE coverage.
Click to expand...
Click to collapse
I have the same problem. Do you already have solved it?
I use only one SIM card so it is not a problem two cards.

really you do not have this problem? if no one knows the solution?

compared with my htc butterfly 2 and another low-end android, one plus 2 running latest Oxygen OS has serious connectivity issues. I compared the signals strength using same sim card in same location (including being connected to the same tower) and One Plus 2 keeps dropping the connection and has really poor signal strength. I have tried the *#*#4636#*#* and tried different network modes, but none of them are helping. Its a real disappointment that the basic feature of this phone is screwed up.
I have tried with CM13 as well. Any ideas if this is a modem version issue?

odeccacccp said:
Try this:
1. You need to make sure you have the correct LTE APN selected in mobile networks and LTE as preferred type.
2. Go to dialer and type in this: *#*#4636#*#*
3. Phone Information
4. Set Preferred Network Type to: LTE/GSM (PRL) - you an play with which one you wanna use but the one I said works for sure. on other roms I have" TD-SCDMA, GSM/WCDMA and LTE"
5. Now click TURN OFF RADIO and wait WAIT few secs. will that button turns to Turn Radio ON
6. Now TURN ON RADIO and wait
7. when u see the triangle for the signal is back, at least black , go down and lick SMSC REFRESH then UPDATE.
8. now just go back to APN settings and go into your LTE APN
9. Change Bearer to LTE
Click to expand...
Click to collapse
Did It.. But it seems like it didn't solve my problem..

Signal loss

Hi everyone,
I already looked for an answer in the forum but nothing conclusive.
My moto g4 play loses signal during calls. The sim card is 3G and so I changed the network manually to 3g on the phone. However the problem continues and I think it even got worse. It happens especially when I'm moving, in the car, etc.
Is there any real solution for this problem? I have seen many users complaining but I did not realize if there was a solution or not.
Can you help me?
Thank you

Since the SIM is 3G, I'm going to assume the network you're using is GSM (ATT/Tmo). It is possible that the cell towers in your area operate on a specific type of GSM frequency, and your signal loss is due to the phone trying to connect to towers not supported by your carrier. If a call drops again, check the Roaming status of your phone in Settings and see what turns up.
Also, it seems odd that you would have to change the network settings at all. Even if the phone is set to prioritize LTE, it should automatically detect the 3G signal and adjust accordingly.

weak signal strength

my mi a1 signal strength is very low.drop frequently from 4g network to 3g or even in 3g network have low strength and voice call doesn't have proper quality.i compare a1 with my other phone in the same room and the other phone doesn't have this problem for example if a1 have 10-11 asu signal in 3g network the other phone have 15 16 asu signal strength.so my questions:
1-anybody else have the same problem and if there is a solution for that
2-this kind of problems can be fix by software update or is hardware problem and something related to design and material of the phone and can't be fix by update?

My problem is Same

Same problem in my phone after december update no improvment

mine never have any network 4G or 3G issue.. it's working fine indoor an outdoor

m.i.89 said:
my mi a1 signal strength is very low.drop frequently from 4g network to 3g or even in 3g network have low strength and voice call doesn't have proper quality.i compare a1 with my other phone in the same room and the other phone doesn't have this problem for example if a1 have 10-11 asu signal in 3g network the other phone have 15 16 asu signal strength.so my questions:
1-anybody else have the same problem and if there is a solution for that
2-this kind of problems can be fix by software update or is hardware problem and something related to design and material of the phone and can't be fix by update?
Click to expand...
Click to collapse
Try putting the SIM in the second slot.
Worked for me....

I got a network issue too and 2nd sim doesn't stay to 2g only if 1st is selected as data. Consuming most of battery due to this. This happened after the first update. Please check of anyone else too has this :/

yanleites said:
Try putting the SIM in the second slot.
Worked for me....
Click to expand...
Click to collapse
i think maybe a little bit better but the problem didn't go away.i compare every network,in 4g and 2g network a1 behind other phones but in 3g network has good signal
does anyone know if this kind of problem can be fix by software update or it's a problem with hardware or design (maybe unibody design blocking signal)of the phone?

prannoytambe said:
I got a network issue too and 2nd sim doesn't stay to 2g only if 1st is selected as data. Consuming most of battery due to this. This happened after the first update. Please check of anyone else too has this :/
Click to expand...
Click to collapse
i didn't understand what was the problem exactly but in my phone you can select one of two sim for data and the sim select for data automatically change to 4g/3g and the other sim will go to 2g only. if you have two sim active it's normal to drain battery a little more but i can't complain about the battery i think it's good overall

m.i.89 said:
i didn't understand what was the problem exactly but in my phone you can select one of two sim for data and the sim select for data automatically change to 4g/3g and the other sim will go to 2g only. if you have two sim active it's normal to drain battery a little more but i can't complain about the battery i think it's good overall
Click to expand...
Click to collapse
My secondary sim finds 3g or 4g signal even it should stay on 2g only

prannoytambe said:
My secondary sim finds 3g or 4g signal even it should stay on 2g only
Click to expand...
Click to collapse
my secondary sim can find 2g or 3g network but no 4g.4g only available to data sim.maybe VoLTE call can be the reason?(my carrier doesn't support VoLTE call)
try this:data sim in 4g ok.the other sim is for call only.dial *#*#4636#*#* then go to phone information set preferred network type to GSM only

m.i.89 said:
my secondary sim can find 2g or 3g network but no 4g.4g only available to data sim.maybe VoLTE call can be the reason?(my carrier doesn't support VoLTE call)
try this:data sim in 4g ok.the other sim is for call only.dial *#*#4636#*#* then go to phone information set preferred network type to GSM only
Click to expand...
Click to collapse
This changed the primary sim to 2g and for 5 min secondary sim found 2g and again it was on 3g. I have weak network for 3g 4g at my place, due to phone switching to 3g 4g I get higher battery drain. My old phone kept my secondary sim to 2g only. I think A1 has issue keeping phone to 2g only

prannoytambe said:
This changed the primary sim to 2g and for 5 min secondary sim found 2g and again it was on 3g. I have weak network for 3g 4g at my place, due to phone switching to 3g 4g I get higher battery drain. My old phone kept my secondary sim to 2g only. I think A1 has issue keeping phone to 2g only
Click to expand...
Click to collapse
for me working.this 4636 menu will change the sim selected for call and SMS (you can select sim one or two for call and SMS) to 2g and the other sim(data sim) will not show in menu. I select that GSM option and several hours later still on GSM.but after that don't go in cellular network-->network operators and search for network maybe that can change setting to defualt.you can check if you are still in 2g mode in 4636 menu or in setting-->about phone-->Status-->SIM status

m.i.89 said:
for me working.this 4636 menu will change the sim selected for call and SMS (you can select sim one or two for call and SMS) to 2g and the other sim(data sim) will not show in menu. I select that GSM option and several hours later still on GSM.but after that don't go in cellular network-->network operators and search for network maybe that can change setting to defualt.you can check if you are still in 2g mode in 4636 menu or in setting-->about phone-->Status-->SIM status
Click to expand...
Click to collapse
Ok I got it , I don't use secondary sim for anything else then receiving the call. So i didn't make it default anywhere. After making it default to calls I could see the option in 4636 for secondary sim. So this solution doesn't work in my condition, I don't know why the just keep the secondary sim to 2g only . I have reported this couple of time but no changes. Hope they find this issue in Oreo update

Solution for Signal Problem

Problem background: I was having problems when phone was getting stuck at WCDMA (found out using network cell info app), losing sms and calls function, and not switching to other network types, requiring a restart or a toggle of the 2nd sim to off and on (I had my sim 2 off most of the time).
Solution: enter *#*#4636#*#* in the phone dialer, phone information, set preferred network type, NR/LTE/TDSCDMA/GSM.
Phone will not connect to WCDMA but for me, this is the better option since LTE signals are stronger in my area.
One benefit was also an improvement to my battery life, I guess because phone will not search for the weaker WCDMA signal anymore.
I hope you find this useful and you also resolve your problem.

rjaygalvez said:
Problem background: I was having problems when phone was getting stuck at WCDMA (found out using network cell info app), losing sms and calls function, and not switching to other network types, requiring a restart or a toggle of the 2nd sim to off and on (I had my sim 2 off most of the time).
Solution: enter *#*#4636#*#* in the phone dialer, phone information, set preferred network type, NR/LTE/TDSCDMA/GSM.
Phone will not connect to WCDMA but for me, this is the better option since LTE signals are stronger in my area.
One benefit was also an improvement to my battery life, I guess because phone will not search for the weaker WCDMA signal anymore.
I hope you find this useful and you also resolve your indigocard problem.
Click to expand...
Click to collapse
Sounds to be connectivity. They should have gave you a new sim, unplug modem, repulug modem. Clear cache, reset phone, this looks for best tower signal. Make sure your on the latest update. These are basic troubleshooting. If nothing call one plus technical support number. They will ask if you've done these steps. They talk you through More steps. Get it fixed!! Do not Hard reset unless instructed to. Get back.

Hodges59 said:
Sounds to be connectivity. They should have gave you a new sim, unplug modem, repulug modem. Clear cache, reset phone, this looks for best tower signal. Make sure your on the latest update. These are basic troubleshooting. If nothing call one plus technical support number. They will ask if you've done these steps. They talk you through More steps. Get it fixed!! Do not Hard reset unless instructed to. Get back.
Click to expand...
Click to collapse
Pretty sure this is not a sim or network problem. used the same sim on an iphone and samsung and never had this issue.

I had signal issues a found turning off smart 5g in settings yielded better LTE and 5g connection there is a reddit post about it even maybe try it if you haven't already worked for me and my device is 8t global on T-Mobile by the way.

eddro22 said:
I had signal issues a found turning off smart 5g in settings yielded better LTE and 5g connection there is a reddit post about it even maybe try it if you haven't already worked for me and my device is 8t global on T-Mobile by the way.
Click to expand...
Click to collapse
Tried this also before but still experienced network getting stuck to hspa+