Develop Bugs

[Q] Galaxy S3 Reception issues. (Rogers/Telus)

hey guys
im in the pickering-scarborough area and my reception sucks. my wifi drops a lot and my signal is weak
i would have returned it but i got this phone second hand and it was originally telus but i unlocked it
when im downtown i get pretty good reception but it still depends on the area that im in.
when i had my iphone 3g i had good reception at home but now i dont
does anyone have any suggestions on apps to help with signal reception. i dont care about wifi, just reception.
I have fresh network but its not that great.
also, are other galaxy s3 users in the gta experiencing reception issues?

bengali548 said:
hey guys
im in the pickering-scarborough area and my reception sucks. my wifi drops a lot and my signal is weak
i would have returned it but i got this phone second hand and it was originally telus but i unlocked it
when im downtown i get pretty good reception but it still depends on the area that im in.
when i had my iphone 3g i had good reception at home but now i dont
does anyone have any suggestions on apps to help with signal reception. i dont care about wifi, just reception.
I have fresh network but its not that great.
also, are other galaxy s3 users in the gta experiencing reception issues?
Click to expand...
Click to collapse
try factory default might help

totti107 said:
try factory default might help
Click to expand...
Click to collapse
factory default what?
im currently running cm10 nightlies (also any suggestions on better roms are appreciated)
i just updated my modem to the rogers basband one. i dont know which one it was before but im testing it out now.

So are you on Rogers or Telus? Because with Rogers, running stock LH1, inside my house I get 3bars on 4G if lucky, my room is the only place at home where I get LTE if at all.
Sent from my SGH-I747M using xda premium

LH1 for Telus is your best bet... Others modems don't connect... Well it depends.. Won't connect with the I747 without the LH1 modem here in Quebec.
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

howlingmoon12 said:
So are you on Rogers or Telus? Because with Rogers, running stock LH1, inside my house I get 3bars on 4G if lucky, my room is the only place at home where I get LTE if at all.
Sent from my SGH-I747M using xda premium
Click to expand...
Click to collapse
im on a rogers plan with a telus phone but i unlocked the phone which is why i can use it on my rogers plan
right now im on the mvllh1 modem. do you guys have suggestions of a different modem to use given my area?

You checked "Yes this is a question"
Guess where it belongs?
Moved to Q&A
FNM

http://forum.xda-developers.com/showthread.php?t=1794927
Oddly enough, he's in the Scarborough area too. Could be a combination of phone + network.

Look into changing your settings under Mobile Network. Network Mode should be LTE/GSM/WCDMA. Also check your APN's for Rogers LTE. Lastly check your Phone Information by dialing *#*#4636#*#*, select Phone Information and change the setting to LTE/GSM auto (PRL).
I was having similar issues when i first installed CM10. It seemed to work after i played around with these settings. I also live in Scarborough and almost always have LTE.
Cheers

XyrusX said:
Look into changing your settings under Mobile Network. Network Mode should be LTE/GSM/WCDMA. Also check your APN's for Rogers LTE. Lastly check your Phone Information by dialing *#*#4636#*#*, select Phone Information and change the setting to LTE/GSM auto (PRL).
I was having similar issues when i first installed CM10. It seemed to work after i played around with these settings. I also live in Scarborough and almost always have LTE.
Cheers
Click to expand...
Click to collapse
Thanks. This did help a little bit. I get 3 bars in my room now but when im at my friends house it still struggles between 0 and 3 bars but majority of time it sits at 2 bars
How do i thank?

Werid 4g speeds, need help ruling out phone or network

I bought a Tmobile Galaxy S3 on new years from staples, and since ive got the phone ive been experiencing strange 4g speeds. While im in my house, I always have full signal strength, and it always says 4G. I live in the Bronx in New York City, and when the 4g is working properly, I get upwards of 20 megabits down, and 1-2 up. Now I could literally be sitting in the exact same spot, and later ill test the phone and it says 0.2 - 0.3 megabits, and like over 1000 ping and the up is so slow it doesnt even measure it. It usually comes back after waiting, turning airplane mode off and on multiple times or doing a battery pull. I find it strange that I can get either 21 mbps or 0.3 in the same house, while always having full bars. In the phone status sometimes it would say UTMS or HSPA, so it does switch from 3g to 4g sometimes. The thing is my previous phone was Nexus S with 3g and im pretty sure I never had a problem loading a simple image in my house because the internet was so slow. I consistently pulled 3-6 mbps on that phone. I tried calling t-mobile 3 times and they give me the same basic crap, like clear your cache, make sure airplane mode is off (really?) make sure youre network mode is on auto (i tried auto and wcdma only and it still gets slow) and all that other stuff. Is there anything else I could try to see if its a network or phone issue?

It sounds like it might be something with your local tower. I would call Tmobile and put in a repair ticket.
Sent from my SGH-T999 using Tapatalk 2

Thanks, I just did that. Called t-mobile and just directly asked them to check for tower issues, and they filed a complaint. They said to check back in 3 days, hopefully this gets fixed, or else it might be the phone. Do you think flashing different modems would change anything?

tigim101 said:
Thanks, I just did that. Called t-mobile and just directly asked them to check for tower issues, and they filed a complaint. They said to check back in 3 days, hopefully this gets fixed, or else it might be the phone. Do you think flashing different modems would change anything?
Click to expand...
Click to collapse
It wouldn't hurt to try. What are you currently running? (rom/kernel/modem)
Sent from my SGH-T999 using Tapatalk 2

Completely stock 4.1.1, with UVDLJA modem, which is the latest I believe. The phone is relatively new so I wanted to try touchwiz before I rooted. Does installing something like cm10 change the modem? Or is it independent of rom/kernel. I saw an application for tmo that can change between multiple modems pretty quickly, I might give it a try.
Sent from my SGH-T999 using xda app-developers app

My opinion
tigim101 said:
Thanks, I just did that. Called t-mobile and just directly asked them to check for tower issues, and they filed a complaint. They said to check back in 3 days, hopefully this gets fixed, or else it might be the phone. Do you think flashing different modems would change anything?
Click to expand...
Click to collapse
I work for T-Mo,
If I may lend my opinion,
To me, it definitely sounds like the tower. If you go from 20Mbit down to 0.2, and with 1000ms latency, it's super obvious there is something
wrong with the tower, or there is significant demand on the tower from other users, hey its NYC population density is insane.
Something to note as well, New York City is "in progress" for "network modernization" where they are switching to 1900Mhz.
This is why some people who have iPhones are now getting 3G in certain areas, unlocked devices, as well as AT&T phones can have 3G down there.
Due to this, since there is quite a lot of switching around going on down there, that's probably what's going on.
Example:
http://www.tmonews.com/2013/01/t-mobiles-network-modernization-what-is-it-where-can-i-get-coverage/
Hope it helps.

I see, well that makes sense. I dont really mind if its a tower issue because thatll be fixed eventually, I just would of hated if I had to replace the phone, it would of been such a hassle because I didnt buy it direct from t-mo. Thanks to both of you!
Also, since t-mobile seems to be using multiple bands for 4g, I guess it would be better to leave it on auto in network settings?
Sent from my SGH-T999 using xda app-developers app

tigim101 said:
I see, well that makes sense. I dont really mind if its a tower issue because thatll be fixed eventually, I just would of hated if I had to replace the phone, it would of been such a hassle because I didnt buy it direct from t-mo. Thanks to both of you!
Also, since t-mobile seems to be using multiple bands for 4g, I guess it would be better to leave it on auto in network settings?
Sent from my SGH-T999 using xda app-developers app
Click to expand...
Click to collapse
If it helps you at all to see if you are on a different band than 1700/2100mhz
You can go into the dialer and do:
*#0011#
Up top mine says band 4
Which is for 1700mhz AWS
BAND 2
which is for 1900mhz PCS.
You might be on band 4 or 2 on a tower by tower basis, or if they are making adjustments
You might be switched but that is above my pay grade lol

Tmobile note 3 slow lte on att

Just made the switch over to att and I am getting really slow lte speeds. Can anybody help?

Fix your APN?
sent from my sm-9005.

@rbiter said:
Fix your APN?
sent from my sm-9005.
Click to expand...
Click to collapse
Tried every APN setting possible already. Searched all the threads and still no help.

There's a thread on here about flashing the AT&T modem and it solving the problem. Plz search and find it...
Here I found it for you..
http://forum.xda-developers.com/showthread.php?t=2522282
Sent from my SM-N900T using XDA Premium 4 mobile app

AdmiralCF420 said:
There's a thread on here about flashing the AT&T modem and it solving the problem. Plz search and find it...
Here I found it for you..
http://forum.xda-developers.com/showthread.php?t=2522282
Sent from my SM-N900T using XDA Premium 4 mobile app
Click to expand...
Click to collapse
Thanks for the advice but I read through the thread already and it doesn't seem like it will improve drastically. So I rather not attempt to flash a modem that may cause a soft brick. My brother has a N900a and gets almost triple the speed of my lte. What gives?

I dont always get fast speeds. I'm guessing at&t phones get higher priority than other phones. There is a build.prop that you can flash/edit that may or may not work. I, myself, haven't made any mods because I get higher speeds usually. Not always. I am on a 900T but using an international 9005 rom with T-Mobile modem still. It really boils down to is the risk flashing a modem or build.prop worth it. In downtown houston I rarely dip below 10mb/s on LTE and occasionally see over 20mb/s. The congestion is real bad here so it is very often I get bumped back down to hspa. Like I said, you have to weigh the risks. I am fine with how it is working now. My post probably hasn't helped you get you where you want to go but it may help you to be content with what you have or may consider flashing an international rom minus modem and see if that helps.
sent from my sm-9005.

I'm on straight talk att sim and it's ridiculous on an att phone I get att quality signal. But with this tmobile phone when home I can only get signal in my bed room by the window . From I walk into building calls and signal dropped dead . It truly sucks. I'm switching back to tmobile as soon as this month is over . I hate paying that extra 30 dollars but a phone is no good in one room .
Sent from my SM-N900T using XDA Premium 4 mobile app

diamantericos said:
I'm on straight talk att sim and it's ridiculous on an att phone I get att quality signal. But with this tmobile phone when home I can only get signal in my bed room by the window . From I walk into building calls and signal dropped dead . It truly sucks. I'm switching back to tmobile as soon as this month is over . I hate paying that extra 30 dollars but a phone is no good in one room .
Sent from my SM-N900T using XDA Premium 4 mobile app
Click to expand...
Click to collapse
I as well am on Straight Talk At&t micro sim and I get pretty decent speeds I believe Straight Talk cap's their LTE speeds at 15 down and I think around 8-9 up which ain't bad for the Chicago area. But there are times where I barely get 2 down and 4 up. I also have a Tmobile Note 3 stock/rooted using a ST sim.

nynexelf said:
I as well am on Straight Talk At&t micro sim and I get pretty decent speeds I believe Straight Talk cap's their LTE speeds at 15 down and I think around 8-9 up which ain't bad for the Chicago area. But there are times where I barely get 2 down and 4 up. I also have a Tmobile Note 3 stock/rooted using a ST sim.
Click to expand...
Click to collapse
The speeds are fine when I actually get a signal . Its the fact that I have dead spots in almost my whole apartment except the rooms located to front of building . It was never like this before .
Sent from my SM-N900T using XDA Premium 4 mobile app

Tmobile Note 3 on ATT Network
I have a Tmobile unlocked phone on ATT and I can't find out anyway to speed up the LTE. I get LTE it seems, but it cuts the speed in half compared to my girlfriend ATT variant Note 3. I tried to flash an AT&T modem to it, but then it would soft brick the device and wouldn't boot. I have tried every APN I can think of, but still no success. I have tried the build.prop, like adding the lines for faster data tweak, but still nothing is getting better. I have full bars, but speed is slow. Do you have any suggestions on what to do, b/c I am out of options. Thanks.

Add me to the list. Just switched over to AT&T from T-mobile, but get very bad speeds. The only reason why I switched over was because with T-mobile, I was getting poor quality signal almost EVERYWHERE, so I had no choice.
I'm curious; if the bands in our phones support the proper AT&T bands and we actually get LTE, it's gotta be a software issue. Modem most likely.

Yeah im sure it has to do with the way the modem is optimized for ATT's 1700 band. I'm also in the same boat and have flashed ATT's modem but it doesn't work. Others have flashed ATT modems but I dont think anyone has been able to successfully see their baseband change in the settings so no one can say whether it worked for sure. I can tell you that the bars have nothing to do with your call signal though, its just your LTE signal strength. If you really want higher signal in your house if LTE seems to drop or be super slow, you should manually switch over to use HSPA+ in your house. Its a pain...i know.
I'm hoping eventually the newer modems fix the 1700 mhz frequency optimization or some devs figure out how to successfully flash N900A modems on the N900T.

LTE speeds
I have great signal almost always it seems like. I have full bars on LTE or 4G/HSPA+, but if I put my sim card in my AT&T variant note I get at least twice as much throughput than with the note 3 tmobile. It has to be a software issue, I have tried to flash att modems with no success. Just got to wait for a tweaked modem. I have even tried tweaking build.prop file and it works a little bit but not much. It is just weird I have full bars with LTE, but I won't be able to get data sometimes, which is really weird. I think there has to be something with the signal bars showing higher dbm that it actually is receiving. Probably another software glitch. Well if anyone has any insight on this issue let us know, please been looking everywhere.

LTE speeds
I think also that the modem is not the only issue. I flashed a kernel today after being on the stock kernel on the T-Mobile and I did a speedtest and the speeds were really low. Flashed another kernel and boom faster speeds back to where I was, maybe higher, but I will monitor to see what happens. But I read that Kernels do affect data speeds sometimes. I am just going to keep looking around to see if any kernels work.

stevestebo said:
I think also that the modem is not the only issue. I flashed a kernel today after being on the stock kernel on the T-Mobile and I did a speedtest and the speeds were really low. Flashed another kernel and boom faster speeds back to where I was, maybe higher, but I will monitor to see what happens. But I read that Kernels do affect data speeds sometimes. I am just going to keep looking around to see if any kernels work.
Click to expand...
Click to collapse
AFAIK it has nothing to do with kernel I might be wrong its just the modem
Sent from my SM-N900T using Tapatalk

Steven
Is there any tweaks that can be done to kinda help the LTE or at least fix my signal bars showing full all the time. I am thinking it is not switching towers when it is supposed to and giving a false signal strength. Is there anything on modifying like you can on Sprint phones with dbm on wimax, where it will switch antennas.

Has anybody flashed the new N900T NE6 based ROMs / modem and seen any difference?

dirrtyswan said:
Has anybody flashed the new N900T NE6 based ROMs / modem and seen any difference?
Click to expand...
Click to collapse
I upgraded the modem and bootloader to the new NE6 version. I'm on Temasek CM11. My observations:
Signal strength is slightly better. Speeds are definitely much better. Prior to the upgrade, I'd get around 6-15/down, 3/up. Now I consistently get 25/down, 10/up.

ajm786 said:
I upgraded the modem and bootloader to the new NE6 version. I'm on Temasek CM11. My observations:
Signal strength is slightly better. Speeds are definitely much better. Prior to the upgrade, I'd get around 6-15/down, 3/up. Now I consistently get 25/down, 10/up.
Click to expand...
Click to collapse
How did you get the new modem to stick? Did you do the triangle away method? If so, did you have to revert to a stock kernel first? I'm trying to upgrade only the modem and leave the bootloader as is. Is that a bad idea?

dirrtyswan said:
How did you get the new modem to stick? Did you do the triangle away method? If so, did you have to revert to a stock kernel first? I'm trying to upgrade only the modem and leave the bootloader as is. Is that a bad idea?
Click to expand...
Click to collapse
It's getting incredibly frustrating to have to repeat this a number of times. I think this morning I had to repeat it already 3 times. Please do a search; there are plenty of pointers on how to get it done. For reference, here is what I did.
http://forum.xda-developers.com/showpost.php?p=52904005&postcount=95

Disable sprint spark

I hate hate hate sprint spark. Is there anyway i can go back to the regular network on kitkat. Please help ...i used to get 4g all the time and i can be in an open area and dont recieve and ounce of 4g now Ridiculous
Sent from my LG-LS980 using XDA Premium 4 mobile app

Turning Bands 26 and 41 off via ##DATA# helped when I was having troubles.
You will need your MSL

geeksmurf said:
Turning Bands 26 and 41 off via ##DATA# helped when I was having troubles.
You will need your MSL
Click to expand...
Click to collapse
Same for me disable those bands and your good. Type in ##data# and choose LTE and disable bands.
Sent from my LG-LS980 using Tapatalk

Has anybody tried to disable bands before, same issue here, no ounce of lte unless i update PRL/profile which only last a few mins.

All I can say is be patient. I had the same issue for a couple of months where I had to cycle airplane mode (or update PRL) to get LTE then promptly lose it. Disabling bands 41 and 26 helped. But after those two months, LTE works great most of the time without doing any of this.
Sprint is likely working on towers in your area.
Sent from my LG-LS980 using XDA Free mobile app

beezar said:
All I can say is be patient. I had the same issue for a couple of months where I had to cycle airplane mode (or update PRL) to get LTE then promptly lose it. Disabling bands 41 and 26 helped. But after those two months, LTE works great most of the time without doing any of this.
Sprint is likely working on towers in your area.
Sent from my LG-LS980 using XDA Free mobile app
Click to expand...
Click to collapse
Sprint has been "working on towers" in my area for over a year. Every time I go into the Sprint stores to ask when LTE will be here its always the same answer: 'Well they are actually working on upgrading the towers right now, so if you are experiencing issues with data connectivity or slow speeds thats probably why. They expect to have LTE fully up and running in 1-2 months'. And as of today, still no LTE. And 3G speeds that are so slow it wont even register on a speed test.
http://newsroom.sprint.com/news-releases/sprint-celebrates-americas-newest-network-with-a-satisfaction-guarantee-offering-wireless-users-a-30-day-riskfree-trial.htm
Click on the link and read the section about 8T8R radios. So basically before Sprint brings LTE to all of its customers they started introducing Spark in select areas. Then also before completing their LTE rollout they will be upgrading the Spark towers. Even after LTE is installed it consistently tests the slowest of all 4 major carriers. And as more people buy phones that are LTE/Spark compatible, it will only get worse.
So yes it is good to be patient. But Sprint's upgrades and improvements are very slow coming so don't hold your breath.

I like it
Lets me know how network is going

Freaking hate Spark. Glad to find this thread... I disabled the two bands and it's MUCH snappier now... Is there any reason I will need to re-enable these bands?

You'll want to reenable those bands unless you want a device that only works on 1/3 of the spectrum that Sprint has in the market. I can see disabling those bands during the upgrade process if you are having difficulty but with a finished product, I can't think of a single reason why you would ever want to disable those bands.

jkcarp94 said:
You'll want to reenable those bands unless you want a device that only works on 1/3 of the spectrum that Sprint has in the market. I can see disabling those bands during the upgrade process if you are having difficulty but with a finished product, I can't think of a single reason why you would ever want to disable those bands.
Click to expand...
Click to collapse
This is ridiculous for me i have only 3g and spotty voice conection ect keeps losing signal, meanwhile my old galaxy note 2 is on lte like a champ. Im going to try switching radios to see if i can make it any better.

Galaxy Prevail Lte
I have a galaxy prevail lte on boost, and I wanna disable the spark bands, when I dial ##3282# and tap lte it doesn't do anything no matter how many times I tap it. Someone please help?

nelsonalexander said:
I have a galaxy prevail lte on boost, and I wanna disable the spark bands, when I dial ##3282# and tap lte it doesn't do anything no matter how many times I tap it. Someone please help?
Click to expand...
Click to collapse
Sorry, this thread is for the LG G2 LS980...

I'm sorry.
I'm sorry but is it really that serious? My question was completely relatable to the topic...

nelsonalexander said:
I'm sorry but is it really that serious? My question was completely relatable to the topic...
Click to expand...
Click to collapse
Yeah it's serious, your phone may have a different behavior than the LS980 due to the service provider unique tweak to stock android on your phone. Once the LS980 hidden menus are unlocked using the SPC code, the bands toggle no problem. Maybe that could be your issue, if it's not, that's why I suggested to find a thread related to your phone. Good luck!

LTE always reverting to 3G/H/H+ on ALL custom and all stock roms

I had LTE for around a month, then out of nowhere, no updates, nothing it disappeared, it's been gone for almost 2 weeks now.
My carrier (O2-UK) says there is no issue, I have literally no idea, I am almost certain it's just Oneplus phones.. but anyone have any info?
As I said, I've tried custom ROM, I've tried all the stock roms clean flashed.

ritchiedrama said:
I had LTE for around a month, then out of nowhere, no updates, nothing it disappeared, it's been gone for almost 2 weeks now.
My carrier (O2-UK) says there is no issue, I have literally no idea, I am almost certain it's just Oneplus phones.. but anyone have any info?
As I said, I've tried custom ROM, I've tried all the stock roms clean flashed.
Click to expand...
Click to collapse
The latest update oos3.4.2 has this issue. However, oos3.2.2 didn't have this issue as my LTE was connecting fine in India.

sidagg said:
The latest update oos3.4.2 has this issue. However, oos3.2.2 didn't have this issue as my LTE was connecting fine in India.
Click to expand...
Click to collapse
I've tried all roms, all OOS versions. Same issue.

No one else has this issue?! Saw a few on google but no fixes...

I can say that my phone often sticks to edge when I disable the wifi, it won't switch to 3g/4g unless I enable/disable it. I believe this was not the case with oos 3.2.1, with which my phone came with (only have it for a week now). This also happens with CM13. I think there was a update to the radio in the last oos update, so this might be the reason.

I am currently on OxygenOs 3.2.4 and my Lte seems to work properly. I tested it on a 4g area for about an hour or more and lte sticks with no drop to 3g. I will test it more and report back.

Lownita said:
I can say that my phone often sticks to edge when I disable the wifi, it won't switch to 3g/4g unless I enable/disable it. I believe this was not the case with oos 3.2.1, with which my phone came with (only have it for a week now). This also happens with CM13. I think there was a update to the radio in the last oos update, so this might be the reason.
Click to expand...
Click to collapse
I used to have solid good 4G here, now I don't no matter what I do. It isn't a network issue either

Did you double check your data SIM card is set to LTE? I had that setting change to 3g through a weird mix of circumstances. Was miffed I wasn't getting 4g and it turned out my SIM was set to 3g max.

nispen said:
Did you double check your data SIM card is set to LTE? I had that setting change to 3g through a weird mix of circumstances. Was miffed I wasn't getting 4g and it turned out my SIM was set to 3g max.
Click to expand...
Click to collapse
I get LTE if I go somewhere else, eg just outside off where I live.
But I had very good LTE where I lived too, inside, outside, then a week or two ago it vanished.

same here always reverting from 3g to 2g biggest issue with this phone
please fix this 1+ we all having hard time with this issue
my 1+3 never stays on 3g or LTE always go back to 2g

Silly suggestion, but are you on the correct APN? My oneplus initially connected on the incorrect APN for my carrier and I wasn't getting LTE, but 3G/H. Once I corrected it, my LTE was constant in the places it should have been.

Works fine for me you probably just getting a stronger h+ signal and it's jumping between mast's

fermata_ said:
Silly suggestion, but are you on the correct APN? My oneplus initially connected on the incorrect APN for my carrier and I wasn't getting LTE, but 3G/H. Once I corrected it, my LTE was constant in the places it should have been.
Click to expand...
Click to collapse
Yes I am

TheLoverMan said:
Works fine for me you probably just getting a stronger h+ signal and it's jumping between mast's
Click to expand...
Click to collapse
That would make no sense. I had LTE for a solid month sat right at this desk, now, none.

Where I am in the UK we have loads of cell towers around me and it's always jumping about. There is an app that lets you pick what cell tower you want to use, I have forgotten it's name but might be worth a look. Or could be they doing work in your area. Sorry can not think what else it could be

The oneplus 3 and oneplus 2 just don't like LTE, they will find any reason to go to H+/3

Same issue
I am on Three UK, have came from a Galaxy S7 Edge, and that got constant LTE in most areas, now my phone seems to prefer H+ a LOT more than LTE, reverting to it whenever it can, not great, OnePlus really needs to address this issue, wouldn't mind so much if LTE in my area wasn't 75Mbps, compared to 10Mbps on H+

Grudenkles said:
I am on Three UK, have came from a Galaxy S7 Edge, and that got constant LTE in most areas, now my phone seems to prefer H+ a LOT more than LTE, reverting to it whenever it can, not great, OnePlus really needs to address this issue, wouldn't mind so much if LTE in my area wasn't 75Mbps, compared to 10Mbps on H+
Click to expand...
Click to collapse
Same issue, same carrier, same frustration

Put me down for the same issue. With faster battery drain on 3.2.4, as well as random complete "no service" signal loss, for maybe 5 seconds. It's annoying as sin, and very disappointing. OnePlus at least is aware of the issue:
https://twitter.com/OnePlus_Support/status/765659124642222081

Fix
Have found no fix, have reverted to S7 edge, has MUCH better LTE and more reliable signal overall.