Although wireless standards like 3G, 4G, and 5G are mostly associated with mobile internet, they also include a phone (voice) component. Up till 4G this was done using traditional circuit-switched telephony service, but with this fourth generation the entire standard instead moved to a packet-switched version akin to Voice-over-IP, called VoLTE (voice-over-LTE). Even so, a particular phone can choose to use a 4G modem, yet still use 3G-style phone connections. Until the 3G network is shutdown, that is. This is the crux of [Hugh Jeffreys]’s latest video.
In order to make a VoLTE phone call, your phone, your provider, the receiving phone and the intermediate network providers must all support the protocol. Even some newer phones like the Samsung Galaxy J3 (2016) do not support this. For other phones you have to turn the feature on yourself, if it is available. As [Hugh] points out in the video, there’s no easy way to know whether an Android phone supports it, which is likely to lead to chaos as more and more 3G networks in Australia and elsewhere are turned off, especially in regions where people use phones for longer than a few years.
The cessation of such basic functionality is why in most countries 2G networks remain active, as they are being used by emergency services and others for whom service interruptions can literally cost lives, as well as countless feature phones and Internet of Things devices. For some phones without VoLTE, falling back to 2G might therefore still be an option if they support this. With the spotty support, lack of transparency and random shutdowns, things may however get rather frustrating for some the coming years.
VoLTE/VoNR.
https://commsbrief.com/volte-in-5g-is-volte-used-in-5g-new-radio-nr-networks/
“In order to make a VoLTE phone call, your phone, your provider, the receiving phone and the intermediate network providers must all support the protocol. ”
You don’t need to have VoLTE — or VoNR (5G) or VoWiFi, which are all IMS-based packet switched services — at both ends in order to be able to make calls. Maybe the author is thinking of “HD Voice”? There is packet/circuit switched interop, otherwise it would be far too limiting. IMS has Breakout Gateway Control Function (BGCF) and Media Gateway Control Function (MGCF) for interworking.
It says specifically “in order to make a VoLTE phone call”, not just any phone call in general. The 2G and 3G legacy layers are going away and this article is about planning for a world where they are gone.
I am in the US and only one single major operator has ANY legacy layer left, it’s only 2G (the others have already shut down 2G, everyone’s killed 3G) and that goes away 2 April 2024.
After which date, the major operators will only offer LTE and NR.
Right, and you can have a VoLTE phone call where only one leg — MO or MT — is VoLTE, whereas the suggestion was that caller, callee and the path between all have to support VoLTE, which is is not the case. I suspect 2G will be around for some time yet, here in the UK at least.
I agree, there are gateways in the core network that can terminate VoLTE. Otherwise how could you call: a land line? The emergency services? Voicemail? etc etc.
When the telcos are explicitly telling you it’s being killed off…and then doing it…saying that is going to be around for a while. Must be hard to breathe with your head that deeply planted up your arse…
IMO VoLTE tech specs and protocol should be open source for all the reasons above. In the US while cellular is not considered a public utility, a massive amount of taxpayer funds are used to subsidize cellular build outs and the ability to make voice calls *should* be public, even if the service is not.
3rd party FOSS phone OSes in particular will be hard hit by this. Ubuntu Touch, and others will not be able to make voice calls (ignoring the pinephone who’s closed source modem does the work). AFAIK Sailfish OS is the only alt OS that had VoLTE on 2 specific phones.
The protocol is completely opensource. You can search and get 3GPP IMS standard on the internet. As to opensource client-side implementation, you can find https://github.com/DoubangoTelecom/doubango . You can run it on a standard GNU/Linux just fine, I’ve got a nano-documentation at https://github.com/phhusson/doubango/blob/master/README-phh
I’m personally working on an opensource IMS for Android https://github.com/phhusson/ims
“I’m personally working on an opensource IMS for Android”
Thank you!
As phhusson said, the protocol is open. But there is another problem lurking in the VoLTE/VoNR world.
The specification is heavily fragmented due to the telco’s race for “the first VoLTE enabled telco” (blame S. Korean telcos here. They have a huge portion in current heavily fragmented status quo)
I don’t know about the status of VoLTE/VoNR implementations in the another country (I don’t have active SIM cards for non S. Korean telcos, thus I can’t poke their IMS implementation), but in here, this causes some headache to its users. You cannot easily attach any foreign phone to the Korean telco out of the box and in most cases, it requires some fiddling with QPST to make it work.
I guess implementing VoLTE/VoNR (and… including another IMS SMS/MMS replacement, RCS) in open source is technically possible, but will face huge fragmentation barrier. You will have to spoof someone else’s SIP user agent to make it work depending on telcos, mock someone else’s behaviors, have a hard time to test it whole over the world, etc.
I visited SK from the US and was able to buy a prepaid SIM and place it in my US phone without issue.
The tech specs, protocol, and even a full implementation are completely open source.
All you need is Kamailio and an EPC.
The guide below even shows how to configure a UE (Android 8.0+).
https://open5gs.org/open5gs/docs/tutorial/02-VoLTE-setup/
Easy as pie. Or, well, not really. And certainly not easy at 100m+ subscriber scaling.
But this exercise will give you a good appreciation for how this stuff all works — and maybe a little awe anytime a VoLTE call actually makes it through. :-)
“newer phones like the Samsung Galaxy J3 (2016)” It was released 31st March 2016. So we are talking 7 years old , nearly 8. Not really that new is it.
not ancient unless you think it is okay to be throwing all those materials every 2.5 years.
2.5 years? I thought you were supposed to throw out your phone every 2.5 weeks. Are you telling me that phones can have a longer useful life than milk, Apple lied to me!
Yeah amen. the windows/pc fanboy treadmill mentality. Sux to be them.
What a weird place to act out.
There are tough decisions for any network as well as it’s customers, and new equipment suppliers. There are no flippant answers. Legacy HSPA+ (3G) can be left alone until it is in the way of progress. Commonly, this is because that particular spectrum has to be re-farmed for newer technology. Carriers rip and replace their base station equipment every 5 years or so, at a huge cost and effort to remain competitive as the best, fastest, lowest latency, etc. Typically the operating bandwidths are getting wider to provide more data throughput, which is where 3G will get in the way. The first LTE phones came around 2010, and VoLTE followed commonly around 2017. While there are hardware realities to phone attrition (broken screens, failing battery capacity, lost), there are probably a few software reasons to upgrade a 5 year old phone, like WiFi calling capability, browsers, modern OS, and lack of security patches that no longer accommodate legacy user equipment. The IoT side is much more complex. If designing a new automation or telemetry device, which technology to bet on that will still be supported over a 10 year lifespan? LTE-M? 5G Stand Alone? A carrier can perhaps have 3 independent BBU’s in a base station servicing HSPA+, LTE, 5G, perhaps even from different vendors depending on who was prime at the time of installation. Costs to keep a legacy service up is at a minimum, crews are trained, it just works. A carrier will not turn down an older technology, until it is in the way of something significantly newer, better, faster, or simply due to physical realities (spectrum). In short, these upgrades tend to be reasonable conclusions. There is always plenty of time and public notice that a sunset change is coming. Some customers with active legacy equipment may likely receive credit incentives to move to new hardware. There should not be any expectation that legacy network support would outlast the user equipment it serves.
The industry has only itself to blame. LTE has it right in the name, Long Term Evolution, was supposed to be able to accommodate sharing spectrum with whatever came after it. 5G NR dropped the ball on that, and the fact that you can’t have a single channel being timesliced between LTE and NR, flexibly according to the number of UE, is purely 3GPP’s doing, and it’s because there was no pressure to keep LTE’s promise.
This shit needs to be legislated.
It’s an environmental travesty that millions, perhaps now billions, of perfectly serviceable devices are obsoleted because it makes someone’s licensed spectrum a few percent more efficient. The spectrum is a public resource, allocated and licensed by the government for the public good. They absolutely can, and must, put conditions on those licenses to serve the public good.
If you follow that argument to its logical conclusion, applying it retrospectively, then we would still be on an upgraded version of AMPS or maybe GSM (before GPRS and EDGE).
Not that there’s anything wrong with GSM!
My Samsung galaxy s4 was kicked off the Verizon network before my v60s was. In fact i had used the same flip phone from Motorola from 2003 until it was denied access December of 2022. I miss that v60s. It had great audio and did calls and texts and no more. It was simple like me. I would buy v60s phones from eBay and move the pc board from shell to shell to make it last as long as I did. Even the reps at the local Verizon store were impressed. I hate having to change because it involves spending more money. Im used to the landline era where you would get a phone and it would work your whole life. You didn’t have to focus on it and wonder when the technology would change and force you to buy another one. In fact if it weren’t for my wife i would not have a phone at all. I just like it better that way.
+1
Which, the wife or the phone? :-)
As if anybody uses their phones for voice calling anymore since spam calls permanently ruined them. Isn’t this kind of fast to be phasing out the immediately previous generation?
Some carriers have better filters than others.
Easy, dont give out your number to sales mobs and block any spam numbers as soon as you get them, they stop in short order.
Given that ISPs often sell user data to third parties, it’s remarkably difficult to avoid getting on a list somewhere, though I’m sure there are more restrictions in various places in the world than others. Still, with more and more people not having a land line to give out, the risk increases that somewhere you provided your number will end up on a list, whether sold out or from a hack, and there’s also likely a lot of war dialing going on as well.
And spam callers’ numbers listed aren’t the actual numbers they’re calling from, so you’re just blocking some random, spoofed number. The only blocking that I’ve found works is if your service allows blocking whole area codes, and then having to deal with whitelisting valid callers after they’ve hit your voicemail.
From above–“As if anybody uses their phones for voice calling anymore…”
Not sure whether this is sarcasm or serious.
I buy a telephone to make and receive telephone calls (what an absolutely NOVEL idea!); and laugh at all the ads for the so-called “Spam Blocker”s–whose sole purpose, of course, is to separate you from your money.
I have a very simple solution to ‘spam calls’; one you and I already pay for—
my phone–via its Contact List–tells me precisely who’s calling; and I also pay good money for ‘VoiceMail’ (you do too; it may not be explicitly stated, but it’s included in your phone bill!). If it’s an important call from someone my phone or I don’t recognize, I don’t answer. Then I check ‘VoiceMail’.
By definition–if a message was not left, it was not an important call, and/or probably was a spam call–a waste of time in any event.
I also laugh at this ‘new mentality” which holds that answering your ringing phone takes absolute precedence over anything else which you may be doing at the time–usually resulting in the insulting of someone else with whom you were having some interaction prior to the incoming phone call.
Your phone does not run your life–unless you consciously choose to let it.
——————————————————–
“Every seemingly complex problem has a very simple solution if you just look at it the right way.”–Douglas Adams
New mentality? In the heyday of landlines, it was expected that a call *would* be answered, by anyone in the vicinity, even if all they were the wrong person and all they could do is find out who called and take a message. If it rang for a long time before you answered, you’d probably apologize for taking so long, unless it turned out to be a salesman. You might even sit by the phone waiting for a call you were expecting, so that you could pick it up quickly but not *too* quickly.
Of course, at some point we got caller id and answering machines, but even then the etiquette was to apologize for not picking up right away.
Well, that’s not an apples to apples comparison. You couldn’t see who was calling, so you had to pick it up since it could be important. Otherwise the person on the other end had to drive to come see you or mail a letter or call again. What sense would it make to not answer? None these are good options.
I mean, caller ID lets me rule out some calls, and voicemail lets me figure out if it was important, but only by waiting for it to finish ringing, waiting for them to record the message, then dialing the voicemail and entering my pin, then selecting and playing the most recent message. Though the kinds that transcribe it live or let you listen in are convenient, like the old answering machine was, I still think it should be reasonable to just take a call for a moment if unimportant or for longer if important, with some level of apology for the interruption same as if you were all in person. An example is “Hey $familyMember, can I call you back?” and either he/she tells me it’s important, or in a few seconds I’ll have rejoined the conversation with whoever I’m with and maybe they’ll text me or maybe I’ll call them back.
Many people buy “cell phones” because they are pocket internet computers. The fact they got called “phones” is just incidental, and integrating your telephone services into a pocket internet computer makes sense. Otherwise we’d all have PDAs with 5G radios and Nokia candy bar phones.
I can guarantee I don’t have voicemail, but several applications allow you to send voice messages to be listened at the receiver’s convenience. Voice call is only useful when I need to reach someone right now, and SMS is completely obsolete.
How’s it obsolete? Despite SMS being a somewhat crappy form of text, text isn’t obsolete and SMS is the most compatible type I’ve got in this context. It can even be automatically bridged to/from email or sent and received by the rudimentary voice control of various vehicles.
Even a great way to do voice messaging trades away things like convenience for the recipient. I might say “Wouldn’t it be great if these voice messages had a transcription I could read when I can’t stop and listen? Wouldn’t it be great if the transcription was already done before I even finish downloading the recording, and if it could be displayed on the screen of paired devices like watches or cars?” And then I would have reinvented text messages using the speech recognition triggered by a button on a modern phone’s keyboard app.
Another great use of SMS: I discovered that BT land lines would read out the text if you texted them.
So them the great source of amusement was texting a salacious or filthy message, and having BT’s computer try to pronounce various obscure sexual terms. Especially, on friend’s land lines!
Knuck knurr.
What an arrogant comment from a shortsighted person. I have a phone to receive phone calls from people who need to reach me, and I’m of the opinion that people calling to scam me because they erroneously think I have medicare don’t actually need to reach me.
Before I got a call filter app, I could get upwards of 30-40 spam calls a day, many of them also leaving voicemails, which can fill up quite quickly at that rate (Verizon has a 20 message limit on voicemail). Your “solution” is laughable at best.
My phones got kicked off for being 3G many years ago. It sucked because the old one was just the right size to wrap my wallet around. I still have the old phone, I use it as a guitar tuner and a camera.
My Samsung Galax S8+ Unlocked was functionally bricked when 3g service ended in the US because unlike the carrier branded versions, Samsung never updated the software to enable their $650 (or whatever it was) 4g LTE flagship phone to have VoLTE like the virtually identical carrier branded phones.
So watch out if your area is just now sunsetting 3g, your “4g LTE” Samsung might not actually be a 4g LTE phone.
I have 2 Samsung phones, both S8’s [not plus] one is a telstra branded rom – it has volte, the other has lineageos 16 it has volte too, but the bonus is it has far more efficient radiomodem drivers, so same hardware, same tower, same sim and its service, but 15-20% Better usable bandwidth especially in marginal reception nooks and crannies. Well worth the time it takes to switch.
Did Samsung fix their glaring vulnerability? Or is enabling VoLTE still an invitation to be hacked within hours?
I have encountered a bigger problem. I bought a new cellphone from Amazon which does support 4G VoLTE but when I put in my SIM card, the data was 4G but every voice call dropped down to 3G. I contacted my telcom provider and they said:
– yes we support 4G VoLTE
– yes your account is setup to use it
– yes we see your cellphone trying to make a 4G VoLTE call and it switching down to 3G
So what is the problem?
They have a limited list of recognized phone manufacturers and models which they have verified and will allow 4G VoLTE calling. Since my cellphone is not on their approved list, it will not allow 4G VoLTE.
I travel alot to other countries and buy a local SIM card and 4G VoLTE immediately appears on my cellphone.
So the problem is NOT my cellphone, it is the telcom company I use.
Why do they do this? The official answer is they need to verify the 4G VoLTE on a cellphone works properly.
The unofficial reason is they are not happy because I did not buy a cellphone from them so they penalize me. Lies lies and more lies.
p.s. This is what happens when companies are run by money hungry short-sighted MBA idiots instead of engineers. All these companies with all their stupid business rules are the creation of these MBA bosses.
I had the same problem. My old phone had the ability to support VoLTE, but ATT decided it shouldn’t be allowed to use this feature on their network, and I had to buy a new phone. What’s even worse, ATT isn’t even my carrier, Cricket just uses their network.
This also made the process of buying a new phone EXTREMELY frustrating because I wanted a device that could have the bootloader unlocked (or rootable at an absolute MINIMUM), so nothing directly from my carrier was acceptable. I eventually had to take a gamble on a phone that would *hopefully* work, and got lucky.
You do know that AT&T purchased Cricket in 2014 when they acquired Leap Wireless the parent company right?
Interested to know if they also do this for other people roaming onto their network (e.g. from abroad)
You could test it with one of your foreign SIMs.
I had Verizon do something like that to me. I threw away the cell phone for 6 years. When I finally got another phone I went with Consumer Cellular. Don’t make me throw my phone away again. I don’t know if I would ever get another cell phone.