Recently my s7 edge appears turned off when people try to call me. Then after a while i get the text saying someone tried to call me but the phone was off (but it was actually on). No problem making calls. It's not that you can represent it, it is totally random and not too frequent but enough to annoy me.
G935F -UAE stock nougat
Does anybody know if this is a hardware problem? a bug ,or is it the carriers fault :fingers-crossed:
eri000 said:
Recently my s7 edge appears turned off when people try to call me. Then after a while i get the text saying someone tried to call me but the phone was off (but it was actually on). No problem making calls. It's not that you can represent it, it is totally random and not too frequent but enough to annoy me.
G935F -UAE stock nougat
Does anybody know if this is a hardware problem? a bug ,or is it the carriers fault :fingers-crossed:
Click to expand...
Click to collapse
This used to happen to me too, i think it was because of carrier and coverage, especially when 4G signal is low.
What i found helpful is keeping my device on 2G only when on Wi-Fi or don't need high speed cellular data.
I use this app to have a shortcut of 2G/3G/4G switch in notification panel, makes switching between 2G and 4G easier.
panart said:
This used to happen to me too, i think it was because of carrier and coverage, especially when 4G signal is low.
What i found helpful is keeping my device on 2G only when on Wi-Fi or don't need high speed cellular data.
I use this app to have a shortcut of 2G/3G/4G switch in notification panel, makes switching between 2G and 4G easier.
Click to expand...
Click to collapse
thanks for your input.
Thing is i NEVER use mobile data, it is off all the time and the apn list is empty (no profiles), i only connect using wifi. Does that still have an effect ?
I hope it is a coverage problem
eri000 said:
thanks for your input.
Thing is i NEVER use mobile data, it is off all the time and the apn list is empty (no profiles), i only connect using wifi. Does that still have an effect ?
I hope it is a coverage problem
Click to expand...
Click to collapse
It doesn't matter if you never use data, device can still connect to 3G or 4G (though in some cases an APN may be needed to connect to 4G, that depends on carrier). In your case, since you never use cellular data, you can safely set your device to 2G only. With 2G you will have better signal for sure, and it's less likely to have missed incoming calls.
Sent from my Samsung Galaxy S7 Edge using XDA Labs
eri000 said:
Recently my s7 edge appears turned off when people try to call me. Then after a while i get the text saying someone tried to call me but the phone was off (but it was actually on). No problem making calls. It's not that you can represent it, it is totally random and not too frequent but enough to annoy me.
G935F -UAE stock nougat
Does anybody know if this is a hardware problem? a bug ,or is it the carriers fault :fingers-crossed:
Click to expand...
Click to collapse
I've had the same problem with a Galaxy J7 2015 also bought in the UAE.
Again not too often but enough to be annoying. I found that selecting 2G/3G without LTE improved the situation.
panart said:
It doesn't matter if you never use data, device can still connect to 3G or 4G (though in some cases an APN may be needed to connect to 4G, that depends on carrier). In your case, since you never use cellular data, you can safely set your device to 2G only. With 2G you will have better signal for sure, and it's less likely to have missed incoming calls.
Sent from my Samsung Galaxy S7 Edge using XDA Labs
Click to expand...
Click to collapse
tried 3g/2g (auto) and couldn't receive calls on my old galaxy w (same sim) i never had any missed calls and it was set at 3g/2g auto
trying 2g now
hello,
i have the same problem..i turned it on 2g but i last calls again...the problem came after the last update in btu and i am pretty sure that other users have also the same problem...
arxontas2323 said:
hello,
i have the same problem..i turned it on 2g but i last calls again...the problem came after the last update in btu and i am pretty sure that other users have also the same problem...
Click to expand...
Click to collapse
i think mine started after getting G935FOJV1DQAV csc update
Related
I got a new HTC touch 3g from Asia and have frustrating problem. On ATT network in US, when the call network switches between 3G and Edge the phone network becomes zero ( no bars) and the calls drop.
This is extremely annoying as the ATT network continuously changes from 3g and edge when driving/walking. Is there anyway to switch off 3g/edge because I don't have a data plan and I don't use the phone for internet.
Or is there a way to force it to be only edge?
Any help would be great!
do a search for nodata.cab, it's originally form the Modaco forum but i've seen it over here too, works great!
Thanks! Downloaded and changed the settings in nodata.
Any ideas how I can test that this works? I still see "E" next to the phone bars.
Thanks a lot.
I think this is no solution: NoData only stops data-connections and does not affect the connection-band that is used for communication with the base-stations of the network (for speaking and data). Your problem are the calls not the data connection that you do not use, IMO.
Try this: "Start/Settings/Telephone/Band" (translated from German). There you can preselect the Band(s) that is (are) used for communication globally.
Thanks. I don't have anything called "Band".
I tried using Bandswitch...has anyone tried it?
countdrakc said:
Thanks. I don't have anything called "Band".
I tried using Bandswitch...has anyone tried it?
Click to expand...
Click to collapse
This sounds good, I do not know the exact English nomenclature because I have a German version. What type of network is displayed next to phone bars now?
MvBoe said:
I think this is no solution: NoData only stops data-connections and does not affect the connection-band that is used for communication with the base-stations of the network (for speaking and data). Your problem are the calls not the data connection that you do not use, IMO.
Try this: "Start/Settings/Telephone/Band" (translated from German). There you can preselect the Band(s) that is (are) used for communication globally.
Click to expand...
Click to collapse
You're right! i was mislead by the question (how to turn of 3G or Edge).
I love my new Galaxy S III, but once again I have no way to force HSPA+ only. I need this option while my phone sits in my desk all day. If I can turn LTE off then I can save battery life and still get calls/texts/emails.
STOP IT AT&T, JUST STOP IT!!! Your really starting to really aggravate your customers by not allowing them to select their preferred network.
I want the network mode option in mobile networks:
GSM/HSPA/LTE (Auto)
GSM/HSPA (Auto)
HSPA (only)
GSM (only)
STOP taking this off all your phones. Every other GSM carrier in the world allows this except you!!!
I hope ALL developers add this toggle in all the upcoming roms.
Your best bet until this is added/fixed, is to turn on wi-fi mode and turn off the mobile data connection.
That way you still can make calls, and have the wifi as your data, and if its off it wont use as much power as HSPA/LTE.
mastarifla said:
Your best bet until this is added/fixed, is to turn on wi-fi mode and turn off the mobile data connection.
That way you still can make calls, and have the wifi as your data, and if its off it wont use as much power as HSPA/LTE.
Click to expand...
Click to collapse
I think you kind of missed the point...
Let's say your at work all day and you don't use your phone much? Let's say your phone gets 1 bar of LTE and 4 of HSPA+. The signal constantly fluctuates ultimately leading to a dead battery much faster.
Wouldn't it be great to just turn LTE off? That way my phone gets a better signal and uses less battery life. Not to mention, I can still receive calls, texts, and e-mails, whereas airplane mode disables everything.
Wi-Fi isn't available everywhere.
PS: AT&T ain't adding ****, they released their first LTE device in November of 2011 and it also lacked this option.
I think you missed the point as well
The reason for turning on wi-fi is to direct the data connection to something other than the chip used for HSPA/LTE. I'm not looking to use the wi-fi connection as an alternative data source. I'm using it to prevent as much battery drain as possible whenever I am not using the phone.
It essentially IS turning off LTE, but it also is turning off your data, and if you don't have wi-fi then you wont have a data connection, but if you do then you will.
Airplane mode is just taking it a step further and blocking calls as well.
So there's no way to turn off LTE? Even via a 4g/3g toggle from the app store?
916x10 said:
So there's no way to turn off LTE? Even via a 4g/3g toggle from the app store?
Click to expand...
Click to collapse
Nope, that's not how it worked on the HTC One X... even dialer codes would just reset on exiting. LTE stays on for some stupid reason with ATT.
A bet a toggle with root requirements will come out later./
mastarifla said:
I think you missed the point as well
The reason for turning on wi-fi is to direct the data connection to something other than the chip used for HSPA/LTE. I'm not looking to use the wi-fi connection as an alternative data source. I'm using it to prevent as much battery drain as possible whenever I am not using the phone.
It essentially IS turning off LTE, but it also is turning off your data, and if you don't have wi-fi then you wont have a data connection, but if you do then you will.
Airplane mode is just taking it a step further and blocking calls as well.
Click to expand...
Click to collapse
Ok? What if you don't have Wifi and your in a very spotty LTE area with fluctuating signal?
Nevertheless, we need the toggle!!!
What about an APN switcher, would that work?
916x10 said:
What about an APN switcher, would that work?
Click to expand...
Click to collapse
Nope, many have tried this but it doesn't stick. We need AT&T to add the option under mobile networks.
MattMJB0188 said:
Ok? What if you don't have Wifi and your in a very spotty LTE area with fluctuating signal?
Nevertheless, we need the toggle!!!
Click to expand...
Click to collapse
Then it would be best to turn off the Wi-fi and the Mobile Data connection, the only reason I have the Wi-fi on is if I'm in an area that has it (home, work, at&t hotspot) otherwise it is automatically turned off (I think?).
And I agree completely, I would love that feature, but until that time we have to make due with what we have, this is my solution, it isn't perfect but it works for me.
mastarifla said:
Then it would be best to turn off the Wi-fi and the Mobile Data connection, the only reason I have the Wi-fi on is if I'm in an area that has it (home, work, at&t hotspot) otherwise it is automatically turned off (I think?).
And I agree completely, I would love that feature, but until that time we have to make due with what we have, this is my solution, it isn't perfect but it works for me.
Click to expand...
Click to collapse
Yes, but like I said turning off mobile data completely turns off the data connection, whereas with this toggle we can change it to EDGE or HSPA+ only, still having a data connection.
I agree I like turning on edge only when I'm at work and home
Sent from my SAMSUNG-SGH-I747 using xda premium
I'm just hoping developers starting adding the GSM toggle via Mobile networks in their custom roms.
AT&T NEVER WILL!!!
It could be the sim card. I have a SIM card from 2007. The network toggle still works on my Thrill. Someone put a newer SIM card in their Thrill and the network toggle is gone. http://forum.xda-developers.com/showthread.php?t=1326760 post 27
cproaudio said:
It could be the sim card. I have a SIM card from 2007. The network toggle still works on my Thrill. Someone put a newer SIM card in their Thrill and the network toggle is gone. http://forum.xda-developers.com/showthread.php?t=1326760 post 27
Click to expand...
Click to collapse
And you hit the nail on the head. It's actually a mix of SIM Card and Radio. What we need is the canadian version of our radio and we will have it back.
Erm would juice defender not fix this? I still get texts and calls but it turns off my data.. plus its free! ( i bought the ultimate though)
Sent from my Axiom MAXX!!
benefit14snake said:
Erm would juice defender not fix this? I still get texts and calls but it turns off my data.. plus its free! ( i bought the ultimate though)
Sent from my Axiom MAXX!!
Click to expand...
Click to collapse
i guess technically it could since it turns off everything (Except calls) and turns it all back on every 15 minutes to check if anything was received on Att servers.
But if hes waiting for an important text or something, it would come delayed until juice defender decided to retrieve it.
not a bad idea though.
Here's an idea, since your at a desk all day, invest $1.32 on monoprice into a USB cable and charge your phone...
Sent from my HTC One X using Tapatalk 2
doctorTJ said:
i guess technically it could since it turns off everything (Except calls) and turns it all back on every 15 minutes to check if anything was received on Att servers.
But if hes waiting for an important text or something, it would come delayed until juice defender decided to retrieve it.
not a bad idea though.
Click to expand...
Click to collapse
I believe it just turns off 3g and 4g on verizon. My calls and texts are instant. Also, if you buy the app you can change frequency. Mine syncs every hour or two. It may be different with att since verizon handles their 4g in kind of a silly way.
Sent from my Axiom MAXX!!
bloodrain954 said:
Here's an idea, since your at a desk all day, invest $1.32 on monoprice into a USB cable and charge your phone...
Click to expand...
Click to collapse
You mean cycle it twice as much as necessary since AT&T has removed the functionality that's needed? :good:
Hi,
Was wondering if anyone got bad reception with their phone. I tried 3 different carriers since I had my ideos, in neither of them I ever had very reliable reception and lately the problem is getting worse. I'm running aurora 4.1a and I loose reception all the time, and the battery drains so quick because it's always looking and looking. My sister, my mum and my dad all have good reception (2 of them with my old carrier and 1 with my current carrier).. I can put my dad's phone (same carrier) next to mine.. he will have full bars with 3g and I'll have no reception at all!!!!!! Then it connects and disconnects again, and so it goes... Anyone having such issues?
Thanks.
Tcm9669 said:
Hi,
Was wondering if anyone got bad reception with their phone. I tried 3 different carriers since I had my ideos, in neither of them I ever had very reliable reception and lately the problem is getting worse. I'm running aurora 4.1a and I loose reception all the time, and the battery drains so quick because it's always looking and looking. My sister, my mum and my dad all have good reception (2 of them with my old carrier and 1 with my current carrier).. I can put my dad's phone (same carrier) next to mine.. he will have full bars with 3g and I'll have no reception at all!!!!!! Then it connects and disconnects again, and so it goes... Anyone having such issues?
Thanks.
Click to expand...
Click to collapse
I'm having the same problem, I'm running Aurora ICS. I use to always have good reception everywhere, Then suddenly I've just been unable to. Any help would be great! If I do find out any fixes to the issue myself I will sure let you know.
Good to know that I'm not the only one! Thanks. Hope we find a fix soon.
I've fixed mine now, What I've done is I've gone into Settings > Wireless & Network > Mobile Networks, and scrolled all the way to the bottom, and simply re-registered on the network and selected Use only 2G Data. Mines now working fine with full connection everywhere. However I don't know if our problems are exactly the same, however this is what fixed mine. Sorry if this doesn't help.
I have the same issue. Mine connects to 3G and has good connection, but then it simply disconnects and moves to 2G or reconnects to 3G some time later. That happens pretty frequently and I thought it was an issue with the carrier, but now I am not sure anymore.
Blefish, that is EXACTLY what happens to me, and I tried 3 major carriers in Australia (the only 3 that have their own actual towers). Just after I posted this thread, I happened to do the same thing as IwAsBlack recommended and... so far it seems to work. I have generally better connection and I haven't seen that ugly no reception icon since! Of course, internet browsing will be generally a bit slower but then again, it's better than staring at the phone for 3 minutes until it reconnects just to open Google.
You haven't stated which model you have. I got rid of a Motorola Bravo for at U8800-51 and I have excellent performance over AT&T (US). Crystal clear even with only one bar and I have never had a dropped call.
Have the same issue on any ROM with any mobile network in Belarus. Can't use 2G as recommended above 'cos of a huge use of mobile internet for some net-radio.
Sorry for bad Eng.
Its a U8800 Q&A forum, I didn't think that I had to state the version since I have a U8800.
Yesterday I tested and kept an eye on for the whole day! The reception since changing to 2G only has been AWESOME! Only had a drop out when I was in the subway (of course!) but aisde from that, I had amazing reception not to mention.. that my phone lasted the whole day with still 15% left!! (3G on, it would have to charge it twice while I'm at work) So, it fixed my reception AND my battery problems.
Tcm9669 said:
Its a U8800 Q&A forum, I didn't think that I had to state the version since I have a U8800.
Click to expand...
Click to collapse
FYI, Ideos X5 U8800 describes four different models.
I know it does. What I meant is that I have the Normal U8800 model, so I didn't feel like it was necessary for me to point any variant model number like PRO or 51 or H, because it's STANDARD U8800
So we can make a conclusion that U8800 does not operate well on 3G. I can't switch it myself because I want to use internet too. And I am pretty sure we can't do anything about it, no matter if the problem is in hardware or software.
Blefish said:
So we can make a conclusion that U8800 does not operate well on 3G. I can't switch it myself because I want to use internet too. And I am pretty sure we can't do anything about it, no matter if the problem is in hardware or software.
Click to expand...
Click to collapse
Mate, if you switch to 2G you will still be able to browse the internet! It will only be a LITTLE bit slower, better than having constant disconnection!!! I constantly use the internet to sync my gmail, send free texts, browse the net and a bunch of other stuff.. works even better on 2G with constant reception, not to mention the benefit of the phone battery lasting a whole day (AND still have internet).. so switch to 2G and you will like it... still good internet only with better reception
Same issue
Having same issue when using GSM/WCDMA auto or preferred modes. works normal on GSM network only.
Even when I have no signal of 3g, gsm is working in the background.
problem arises when I have a call, 3g signal drops to minmimun, after the call phone tries to reconnect with the 3g signal but drops the GSM signal in the process.
Try this , as soon as you disconnect the call, try to call yourself from other at that instant only. Your phone will be shown unreachable because phone drops the GSM signals.
rdagar said:
Having same issue when using GSM/WCDMA auto or preferred modes. works normal on GSM network only.
Even when I have no signal of 3g, gsm is working in the background.
problem arises when I have a call, 3g signal drops to minmimun, after the call phone tries to reconnect with the 3g signal but drops the GSM signal in the process.
Try this , as soon as you disconnect the call, try to call yourself from other at that instant only. Your phone will be shown unreachable because phone drops the GSM signals.
Click to expand...
Click to collapse
Mine works on wcdma, but that is because i have the radio.
Sent from my U8800-51
Hi All,
I have been facing major call dropping issues on my new Samsung Galaxy S4 which i previously thought to be a problem with my new postpaid connection. but later on searching realized this to be a bug which many others are facing world wide. I couldn't find any proper solution to it other than this.
What is did is change in settings>connections>more networks>mobile network>network mode> then select gsm only. Have been using it for 2 days now and seems the issue is resolved.
Might help others.
This isn't a fix, why would I run my phone only in 2G / Edge mode... for a 3G/4G device???
There is something strange going on here, I've replicated this issue on 3 different carriers in 3 different countries (AT&T = USA, Chunghwa = Taiwan, China Unicom = China), so it's NOT a network issue. I strongly suspect that the first batch of Samsung GT-i9500's have faulty network chips, there is no other explanation as to why this is a continued issue even after all these software updates.
I had a reception problem with the I9505 too, so it's seems the hardware isn't the problem. With the newest firmware, the problem is gone.
My reception is great, only in shelters it goes down to zero bars and still didn't had any call drops.
I use an I9500 which I bought it on 13/05.
chalid said:
I had a reception problem with the I9505 too, so it's seems the hardware isn't the problem. With the newest firmware, the problem is gone.
Click to expand...
Click to collapse
This isn't a RECEPTION issue. Randomly, throughout the day:
1) Signal will go from full bars to NIL... I'm talking airplane mode with the circle with a line through it.
2) Some time later (a few seconds to longer sometimes), the signal will come back along with 3G / H+.
It has improved with software updates, but it still happens and is completely random both time and location wise. The worse part is, this will happen sometimes in the middle of a phone call, which means you suddenly get disconnected. And yes, this happens when I'm sitting in one spot with a strong signal, so something is seriously wrong with some of these early i9500's.
arindam_mitra1985 said:
Hi All,
I have been facing major call dropping issues on my new Samsung Galaxy S4 which i previously thought to be a problem with my new postpaid connection. but later on searching realized this to be a bug which many others are facing world wide. I couldn't find any proper solution to it other than this.
What is did is change in settings>connections>more networks>mobile network>network mode> then select gsm only. Have been using it for 2 days now and seems the issue is resolved.
Might help others.
Click to expand...
Click to collapse
I yet have to face this issue. You using i9500?
Happened to me with a self cutted microsim. Replaced it with a microsim factory made solved my problem.
I was experiencing the same issues with my i9500. It all solved when I flashed MG9 modem. Since then, I´ve never lost signal or service.
siffar said:
I yet have to face this issue. You using i9500?
Click to expand...
Click to collapse
Yes I use 9500 and my problem is gone now.
Sent from my GT-I9500 using xda premium
There have been several other network related issues with s4..all with different solutions. .but as of now the issue I faces was random call disconnects which is gone after selecting only gsm as im on 2g..
We can discuss all problems related to s4 network and their probable solutions in this thread... hope that might help many..
Sent from my GT-I9500 using xda premium
Have the same problem whit telenor in denmark. Talked to telenor about it. And they told me after some test, that the phone refuse to change from 4g to 3g when there is a incoming call.
But when i'm at the 3g /gsm network only i'm getting all incoming calls
Sent from my GT-I9505 using xda premium
Frankness said:
Have the same problem whit telenor in denmark. Talked to telenor about it. And they told me after some test, that the phone refuse to change from 4g to 3g when there is a incoming call.
But when i'm at the 3g /gsm network only i'm getting all incoming calls
Sent from my GT-I9505 using xda premium
Click to expand...
Click to collapse
Any probable fix??
With my device no issues perfect
Sent from my GT-I9500 using xda premium
It was all good with MDM.. Then I flashed the German rom and updated to MGA and then MH2. Both of them(MGA and MH2) find it hard to stick to the 3G signal and it just drains the battery. I put it to GSM only (2G) and the signal is full but the battery in my opinion is still not AS good as MDM. I sooo soooooo hope they fix it in the next update and soon!
arindam_mitra1985 said:
Hi All,
I have been facing major call dropping issues on my new Samsung Galaxy S4 which i previously thought to be a problem with my new postpaid connection. but later on searching realized this to be a bug which many others are facing world wide. I couldn't find any proper solution to it other than this.
What is did is change in settings>connections>more networks>mobile network>network mode> then select gsm only. Have been using it for 2 days now and seems the issue is resolved.
Might help others.
Click to expand...
Click to collapse
hi guys i have a different issue i hope u guys can help
when i am on call other person cannot hear my voice untill i open my loudspeaker..
try to flash latest update
cmd512 said:
This isn't a fix, why would I run my phone only in 2G / Edge mode... for a 3G/4G device???
There is something strange going on here, I've replicated this issue on 3 different carriers in 3 different countries (AT&T = USA, Chunghwa = Taiwan, China Unicom = China), so it's NOT a network issue. I strongly suspect that the first batch of Samsung GT-i9500's have faulty network chips, there is no other explanation as to why this is a continued issue even after all these software updates.
Click to expand...
Click to collapse
I've had the same issue on 4 carriers: ATT, China Unicom, China Mobile (2G only), Hong Kong (forgot the carrier). This only happens on my I9500 because I cannot replicate it on my HTC One. In all instances where my I9500 craps out on me my HTC produces a strong reliable signal that never drops.
Same thing here... it happens on China Unicom, Chunghua (Taiwan), and AT&T. There is something seriously wrong with a HUGE lot of i9500's.
I have the i9505 and I only have 3 options in the network mode setting menu not 4 like I was told by other users there should be.
My network data connection drops out more often than its connected reguardless of the signal strenghth bars or also despite the about phone signal information.
I have tried a few roms all with the same problem. Im on the 3 network uk I had galaxy note before the s4 and never experienced any problems at all
It is also not area related as I have checked the coverage for the area and im in a fantastic area for cover but if I am indoors outdoors at home my dads or the shops still the same constant no internet connection error the h or h+ or 3g icon just vanishes from the too for no reason.
Can anybody at all offer any help or advice in any way in reguards to it or is it most likely I have a bad handset?
If I have the network set to auto or wcdma it is the same problem .... if I select gsm only I dont get any data internet connection at all is this right?
There is no wifi on either to cause any interferance I keep it turned off on the handset and bluetooth is off too
Thanks for any help or advice
Sent from my GT-I9505 using Tapatalk 2
Hmm, really bizarre that both 9500 and 9505 handsets are seeing the same phenomena. Could it be something software related then?
Question: For those that see this cutting out and returning of network signal, do you have a bunch of stuff disabled / uninstalled / removed?
I just flashed G930U firmware (Oreo RG3) on my verizon S7 and overall I'm much happier with my phone. But, sometimes when placing a call with a strong LTE signal, the mobile data disappears and becomes unavailable until the call is completed. The strange thing is that it only happens 50 percent of the time. I've changed my network settings from global to LTE/ CDMA but that doesn't fix the problem. Is this a known issue with the "u" firmware? Or is it perhaps only prevalent on this particular version I installed? Any feedback is appreciated! Thanks!
maxforwardspeed said:
I just flashed G930U firmware (Oreo RG3) on my verizon S7 and overall I'm much happier with my phone. But, sometimes when placing a call with a strong LTE signal, the mobile data disappears and becomes unavailable until the call is completed. The strange thing is that it only happens 50 percent of the time. I've changed my network settings from global to LTE/ CDMA but that doesn't fix the problem. Is this a known issue with the "u" firmware? Or is it perhaps only prevalent on this particular version I installed? Any feedback is appreciated! Thanks!
Click to expand...
Click to collapse
I don't think that the devices stay connected to 4G LTE while on the actual phonecall as it uses the data maybe for the enhanced calling?
I noticed the same change in connections on my Verizon s7 and att s4. It varies and changes during initiated outbound calls or once a call is incoming. Even seconds before incoming calls I see it drop from 4g LTE down to no internet at all. Then without wifi connected during those ones you can't get online while in call. It depends on phone Carrier like Att, Vzw, and even tracfone brand devices.
It usually cuts back to 3g or H+ and even old Edge/gprs or worse, 2g speeds until the calls are complete. Then regular 4g LTE will come back if your phone is working. This is all from personal experience so please don't take what I say over the other developers who might be able to explain what it is happening a little better.
Hope this helps either way!
P.s- It also probably depends on how strong your signal is to determine what speed you will drop down to during calls. Exp. 4g lte,4g,H+,H,3g,2g,edge,gprs,wap.