Any one else loosing LTE data and droping to hspa while on a call. Happening to both my vivid and skyrocket.
Located in Houston, Tx
The reason for this is that, currently, LTE is data-only. Until LTE providers begin to deploy Vo-LTE (Voice over LTE. Basically VoIP, on and LTE network), the only way you will be able to engage the voice stack on your hardware and access data at the same time is if you fall back to UMTS, which has always integrated both services (voice and data) together.
Unlike Verizon lte, art lte uses circuit switch fallback. Can't do hspa and LTE at one time.
Sent from my HP Touchpad using xda premium
THAT SUCKS ATT!!!! I have to talk & use internet on the HDSPA+ network....it seems so slow. Am I the only person this happens to?
It happens to *everyone* because that is the way it works. Notice that every time you make a call the "LTE" tag goes away....and stays gone until you hang up and the phone reselects back.
There will not be any LTE voice until an IMS is up and running...
Jade Eyed Wolf said:
The reason for this is that, currently, LTE is data-only. Until LTE providers begin to deploy Vo-LTE (Voice over LTE. Basically VoIP, on and LTE network), the only way you will be able to engage the voice stack on your hardware and access data at the same time is if you fall back to UMTS, which has always integrated both services (voice and data) together.
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I know its data only. But dont see why it has to drop off. I have been playing with the build.prop. And it has
#device supports simultaneous 1x voice + LTE
#ro.config.svlte1x=true
So i guess at one point we will have this ability.
This phone only has one radio built in and can't run on both UMTS and LTE at the same time.
I think that setting is referring to a Verizon type LTE device. They have two radios and don't do CSFB like the Vivid/Skyrocket.
Each phone type has it's own pros and cons.
After digging through pages of posts about data speed issues and 2G vs. 3G vs. 4G/LTE, can someone with good expertise and knowledge summarize exactly what the phone supports and how it does it? I am seeing conflicting comments, so it is a little confusing. Also, please clarify a comment I recall seeing from at AT&T person that that the Vivid has one radio that switches between LTE and HSPA+ rather than having as separate 3G radio as earlier LTE phones did.
Or point to a good tutorial.
Thanks
I'll see if I can help!
So in order from slowest to fastest, the GSM data technologies are:
2G:
-GSM
-EDGE
3G:
-UMTS
-HSPA
-HSPA+
4G:
-LTE
Most Android phones display these as G, E, 3G, H, & H+ (don't know what stock Android displays for LTE). The Vivid, however, displays G & E, then displays 4G for 3G, H & H+, then 4GLTE for LTE. So no matter what 3G network your on, it'll show 4G (because AT&T thinks H+ counts as 4G), then when you're on an actual 4G network, it'll show 4GLTE.
As for the single radio, yes, that's true. LTE is a GSM based technology, so a single radio can handle all of the above connections. This is different from Verizon, which uses CDMA for its 2G & 3G networks, then switched to LTE for its 4G network, necessitating two different radios: one for CDMA, one for LTE. AT&T, however, has been GSM from 2G on, so one radio can handle everything. This will most likely continue to be the way it works: Verizon (and eventually Sprint) phones will require two radios for two technologies, AT&T/T-Mo phones will only require one.
This leads to one consequence, however, concerning simultaneous data & voice. No LTE network currently implements voice communications, they're purely data. Even when they do implement it, it'll be VoIP based, so it'll just be more data (This will be called VoLTE for Voice over LTE). Therefore, since this isn't implemented yet, phones must revert to the 3G network to make voice calls. On Verizon, since they're two different radios, you can continue to use LTE data while using CDMA for voice. On AT&T, they're the same radio, so dropping down to 3G drops the LTE connection. You can still use simultaneous voice & data (as you can on just about any GSM based network), but you just don't get LTE speeds.
Make sense? Let me know if that helps!
Thanks, BJG222
That's what I wanted to know. I appreciate the info.
brucegil said:
That's what I wanted to know. I appreciate the info.
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Click to collapse
No problem! Glad I could help!
bjg222 said:
I'll see if I can help!
So in order from slowest to fastest, the GSM data technologies are:
2G:
-GSM
-EDGE
3G:
-UMTS
-HSPA
-HSPA+
4G:
-LTE
Most Android phones display these as G, E, 3G, H, & H+ (don't know what stock Android displays for LTE). The Vivid, however, displays G & E, then displays 4G for 3G, H & H+, then 4GLTE for LTE. So no matter what 3G network your on, it'll show 4G (because AT&T thinks H+ counts as 4G), then when you're on an actual 4G network, it'll show 4GLTE.
As for the single radio, yes, that's true. LTE is a GSM based technology, so a single radio can handle all of the above connections. This is different from Verizon, which uses CDMA for its 2G & 3G networks, then switched to LTE for its 4G network, necessitating two different radios: one for CDMA, one for LTE. AT&T, however, has been GSM from 2G on, so one radio can handle everything. This will most likely continue to be the way it works: Verizon (and eventually Sprint) phones will require two radios for two technologies, AT&T/T-Mo phones will only require one.
This leads to one consequence, however, concerning simultaneous data & voice. No LTE network currently implements voice communications, they're purely data. Even when they do implement it, it'll be VoIP based, so it'll just be more data (This will be called VoLTE for Voice over LTE). Therefore, since this isn't implemented yet, phones must revert to the 3G network to make voice calls. On Verizon, since they're two different radios, you can continue to use LTE data while using CDMA for voice. On AT&T, they're the same radio, so dropping down to 3G drops the LTE connection. You can still use simultaneous voice & data (as you can on just about any GSM based network), but you just don't get LTE speeds.
Make sense? Let me know if that helps!
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Wow thanks, a very helpful summary of so much **** otherwise kinda complicated to figure out.. quick question, under the Network menu, my phone always says HSDPA, not any of the other options you listed above. This means..?
Here is an interesting read...Explains alot, considering I bought my White Vivid in Houston and got amazing speeds on LTE, and can barely stay locked on an LTE signal at home here in the SW burbs of Chicago.
http://www.pcmag.com/article2/0,2817,2393286,00.asp#fbid=ruQf5IEExI0
Actually, HSPA+ is also categorized as 4G.
dizzyraider said:
Actually, HSPA+ is also categorized as 4G.
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Well, AT&T & T-Mobile claim this, but it's not really true. UMTS = 3G; HSPA was an upgrade to that, call it 3.5G; HSPA+ is an upgrade to HSPA that incorporates higher bandwidth behind the scenes, more of a 3.9G. LTE's actually a new protocol. Technically, by the initial ITU standards, that's not even 4G (LTE-Advanced, the next upgrade to that, is the only one that does), but they've since expanded the definition to include LTE, too.
so we don't get a different symbol for 3G...so how do we know when we are using 3G verses HSPA and HSPA+ ? (other than speed)...
sucks...
Hi all, I'm running AOSP 5.1.1 on my XT1068 and would like to know if there is a way that I can possibly set both SIMs to 2G ? I've noticed a couple of thing; (a) obviously 2G uses less power than 3G and for just occasional updates is sufficient and (b) this may sound strange but which SIM I set to 3G always has less signal bars showing.
I've tried the SIM settings but can only set one SIM to 3G and the other to 2G.
Thanks in advance of any assistance you can offer.
there's no way , it's a hardware limitation , 2G and 3G work on different frequencies and smartphone MODEM can not work with two chips on the same frequency operation, it can not even keep the data activated during a call.
LudwigFerdinand18 said:
there's no way , it's a hardware limitation , 2G and 3G work on different frequencies and smartphone MODEM can not work with two chips on the same frequency operation, it can not even keep the data activated during a call.
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thankyou for your reply. I can understand how this may be a limitation with the xt1068 but there are phones available that can do 3G on both SIMs some newer chinese models can even do 4G on both SIMs and if that's the case then surely there must also be phones that can also do 2G on both SIMs, but like i said I take your point that the XT1068 may not be one of those phones.
LudwigFerdinand18 said:
there's no way , it's a hardware limitation , 2G and 3G work on different frequencies and smartphone MODEM can not work with two chips on the same frequency operation, it can not even keep the data activated during a call.
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2g and 3g of the same carrier uses the same frequency, don't know how they differ but the frequency band is the same.
It's dualasim standby, it think that modem hop signal from Sim to Sim,
I use mine with both sims 850mhz frequency (same carrier same country) and i can set both sims to 2g but I haven't see any improvement in battery life except when I deactivate one Sim, but I don't know why 3g have the limitation to one Sim at the time.
This is my second phone dualsim standby and it's the same.
xzyk said:
thankyou for your reply. I can understand how this may be a limitation with the xt1068 but there are phones available that can do 3G on both SIMs some newer chinese models can even do 4G on both SIMs and if that's the case then surely there must also be phones that can also do 2G on both SIMs, but like i said I take your point that the XT1068 may not be one of those phones.
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I think those phones are dualsim active it means have two modems.
Having two fast "networks" the phone only uses one data connection at a time, It's for places where carriers operate only in 3g or 4g, not really needed in my country.
My 2 cents
So I dont know if anyones had this issue, or if someone can answer this questions as to why...but ever since I got my S8, ive never been able to use VOLTE with T-Mobile...
I have finally found my fix... using *#2263# I went in and disabled all bands aside from band 12... then slowly added back in tmobile LTE bands one by one... Band 2 was causing the hiccups for me... so now I have all bands enabled aside from band 2 with no issues.
With band 2 enabled and volte enabled, i can hear the other person fine, however they cant hear me... band 2 disabled, perfect clarity. And this was all over so not just a local tower issue.
Any ideas???
As most implementations of 5G networks is 'non-standalone' (i.e. cannot handle calls, texts and data without another network band being active at the same time), typically devices will be connected to both LTE and 5G networks, which can obviously impact battery life.
Does the VoLTE option on the Samsung S21 Ultra mean that the secondary connection is not required and everything works over 5g, or will the device maintain both an LTE and 5g connection regardless of VoLTE being on?
Been answered elsewhere -
If the user-equipment (device/SIM combination) doesn't support VoLTE, then the network will use CSFB (Circuit-Switched Fallback) to drop the device to 2G/3G voice.
VoLTE allows for voice calls over 4G, the 5G equivalent is "VoNR" which is not currently deployed on EE.