A Look At Voice Over LTE and HD Voice

hey everyone it's Collin in a previous video I mentioned a new technology called voice over LTE and I figured you know it might be worth spending a couple of minutes going through a brief history of how audio has been delivered over digital cell phone networks and how that relates to voice over LTE and the upcoming HD Voice initiative that will start to see out of cell phone companies so this is standard cell phone audio it's kind of the typical murky not very crisp not very articulate type of sound that you're used to hearing when you call someone on the phone the human ear can recognize sounds from a range of 20 to 20,000 Hertz that's what gives you really deep lows and really crisp eyes it's high fidelity audio it's it's how we hear music out of really good headphones or anything like that traditional audio from a phone system whether it's analog as a home phone or digital through cell phone has a very small range within that audible spectrum that we can hear it's only 300 to 3400 Hertz that was done for a reason because the human voice really only lies within that range there's no reason that provide really deep bass or really crisp eyes when the vast majority of the time the kind of sound you're going to send through a telephone system is just human voice you're talking to someone the problem is that because it is kind of murky audio intelligibility tends to suffer you have to be really articulate when you're talking to someone in order for them to fully understand what you're saying which is why if you mumble you can't really hear someone very well and also if you're trying to spell something out you have to be very clear or use something like the pilots alphabet if I'm trying to say ABCD efg over the telephone it's kind of hard to tell the difference sometimes between say C and D which is why a lot of times when you spell something out you've got to say charlie delta instead just to overcome these inherent limitations in the bandwidth essentially that you get for cell phone audio the way that cellphone audio is transmitted depends on the carrier that you're on there's really two standards for this legacy audio gsm and cdma they both transmit data in different ways and on different frequency bands but ultimately they send the same kind of audio with the same type of frequency spectrum so they found about the same but here's what voice over LTE sounds like it's using a new technology called or branded I should say as HD voice there's a couple of standards that HD voice uses but the big thing to understand about voice over LTE is that it's fully digital packetized audio it's sent over the data stream of the cell phone connection instead of kind of the underlying voice stream that's reserved just for audio communication this is why people on legacy network CDMA networks in the US that's Sprint and Verizon why they can't surf the web and talk on the phone at the same time it's because on those types of networks data and voice are channeled over the voice portion of the network LTE pushes everything into the data portion of the network there's really no reserved always portion of it anymore if LTE isn't available then your phone has to fall back to the legacy network in this case HSPA+ or on some other carriers CDMA there's two different audio standards for voice over LTE and it really depends on the carrier's to which one they want to implement the most common one at least in the u.s. so far is called AM rwb adaptive multi-rate wideband regular audio over a telephone network as we said was 300 to 3400 Hertz but AM RWB can go from 50 to 7,000 Hertz it gives you a much wider frequency response it gives you some low-end it gives you better high-end and because it's a more enhanced compression algorithm it's able to give you better detail within that audio stream while using less bandwidth then even a legacy audio channel does I'm using AM rwb right now because the carry I'm on AT&T here in the United States has chosen to implement that right now I'm actually one of lucky few because AT&T is only lit up voiceover LTE and a few markets and Minneapolis happens to be one of those few but as time goes on AT&T and also Verizon have committed to deploying this to more markets and I'm sure t-mobile and Sprint are going to be pushing that as time goes on as well voiceover LTE has been deployed to several other markets around the world and it's quickly becoming the standard which way the carrier's decide to go with the whole HD Voice thing is really up to them and I think it's probably going to end up being mrw be there is a competing standard call AAC eld that's actually the standard that Apple's FaceTime audio uses and it's really closer to the way that music files are encoded like you would get from iTunes it offers up the full frequency response from 20 to 20,000 Hertz so it gives you pristine audio it does compress the audio but it's very very impressive so none of this would really be a fair comparison unless we had some sort of at least semi-scientific control I'm talking on the phone again here but I'm not really talking on the phone I'm just talking into it I've got the voice recorder app going on the phone and this is just kind of a test of what the iPhone 6 Hardware sounds on its own so we can use it to compare against the two previous samples it's going to sound a bit cleaner and a bit clearer but remember companies design phones for you to talk on the phone with so they're not going to put the most high definition audio circuitry into the so how much farther can they push HD voice well that's potentially a limitation of the phone hardware itself so that's a pretty good comparison I think between traditional telephone audio and what the future holds I can't test out a say eld over a cellphone Network because my carrier which happens to be 18 teeth here in the US hasn't deployed that one yet but if carriers do you can expect even better sound than what you just heard that said I think HD Voice is really pretty impressive and the fact that you don't have to keep asking someone wait can you repeat that what did you say I didn't hear you very well well that's probably worth it in and of itself couple of things that I should note is that this is a fairly new technology it hasn't been deployed everywhere yet you also have to have a phone that capable of using it it's not simply a matter of having a phone that can do LTE data the phone hardware has to be able to also support specifically voice over LTE there's a few models available worldwide better compatible with that standard the most common ones that you'll see are going to be the iPhone 6 and 6 plus some of the newer Samsung Galaxy phones like the galaxy s4 and s5 and then also the most recent Sony Xperia phones like the z2 and z3 another thing I should note is that a lot of things still need to be hashed out between carriers in terms of interoperability yeah you may be able to call someone within the same carrier and be able to get HD voice but what if you need to call someone who's on a different carrier and of course the biggest thing is what if you're on a cell phone and need to call a landline well a lot of landline these days are still analog and it's not looking likely that they're going to move to any sort of digital technology ever you know any any time soon so things are going to take a while to shake up and in that market ultimately you probably will get HD Voice within the next five to ten years if you're calling a business if you're calling into a call center and imagine how good whole music is going to sound over HD voice as well hopefully they'll actually just start playing decent music to make it worth it anyway hopefully this video was helpful and gave you an idea as to what the future holds if you like this video please give me the thumbs up I really do appreciate those and they helped quite a bit but I also appreciate is subscriptions if you want to hit the subscribe button down there I've got videos coming out every Tuesday you'll get automatically alerted to those they're not always cellphone related they're not always gaming related but they're always technology related so hopefully it finds something you know interesting to you as always though thank you all so much for watching

Channel: This Does Not Compute

Views: 56,920

Rating: 4.8806586 out of 5

Keywords: LTE, Wideband Audio, HD Voice, VoLTE, Voice Over IP (Industry), Voice Over LTE, cell phone, smartphone, iphone, galaxy s4, galaxy s5, iphone 6, xperia z2, xperia z3, AT&T, Verizon, T-Mobile, Sprint, CDMA, GSM, HSPA, Sony Xperia (Brand), Samsung, Phone, Cell, Nokia, Wireless, Phones, Review

Id: CPFiufYmtAc

Length: 9min 33sec (573 seconds)

Published: Tue Sep 30 2014