What really is VoLte?

[teamgs3]

Can someone explain to me what is Voice over LTE? I keep hearing about and haven't heard any info on it.

[gr8nuguy]

its basically using internet (lte connection in this case) to transmit your voice from one from to another, just like voip

[xenadu]

Takes voice, digitally encodes it, then packs it up into individual IP packets. Skype, Vonage, most PBX/call center systems, etc all use this technology.

 

VoLTE is using the built-in Quality of Service support to ensure voice packets get priority, along with all the signaling for setup/teardown of calls, dialing, etc. IIRC, it's part of the LTE-Advanced spec but others can give more specific info.

 

 

Legacy networks tended to divide voice traffic from data traffic and put them on separate channels, often circuit switched*. This is true for both the telephone and cellular networks, though the situation is actually really complicated.

 

* in modern terms circuit switched is less distinct from a routed IP network, it basically just means the "circuit" has bandwidth reserved and the routing fixed at time of setup, whereas IP is more of a moment in time QoS and packets can dynamically re-route. Even that's not a fully accurate summary of a complex question.

[teamgs3]

So whats gonna be better?

[Fraydog]

That depends on where you live.

 

In the cities, VoLTE will be a better tech. In rural areas, I wouldn't be running so quick to dump GSM, WCDMA/HSPA+, or CDMA1X/EV-DO. It's going to be a while, probably in 3GPP Release 12, before some of the problems with LTE propagation and call handoffs get solved.

[xenadu]

So whats gonna be better?

 

That's a loaded question and people have differing views around here.

 

 

What is certain right now is everyone world-wide has pretty much agreed to a single global LTE standard and that standard's voice support has coalesced around VoLTE.

[Guest 503ducati]

Can someone explain to me what is Voice over LTE? I keep hearing about and haven't heard any info on it.

Here's a good thread: http://s4gru.com/index.php?/topic/2247-volte-vs-1x-advanced/

[lordsutch]

VoLTE is "better" in the sense that phone calls will be cheaper, because carriers won't need dedicated frequency space for voice traffic on towers, and can use the same technology to handle voice traffic as they can for data traffic, which will probably reduce per-minute pricing even more. The disadvantages relate to signal robustness (LTE's signal characteristics are better tuned for high-density urban areas than CDMA-1X or GSM were) and the general issues associated with a new technology (working out the bugs).

 

Basically it's the same transition Sprint has gone through from Nextel Direct Connect (basically circuit-switched) to Sprint Direct Connect (QChat is SIP VoIP + quality-of-service + Qualcomm special patented magic to make the shutdown/connect more responsive). Having said that if anything VoLTE is less technically challenging than QChat, since people making phone calls can deal with connect/disconnect latency much better than walkie-talkie services can - people expect a phone call to take 20-30 seconds to be connected, while "walkie talkie" services are supposed to connect in milliseconds and so people start throwing things, complaining to customer service, and canceling their accounts when it takes much longer.

[teamgs3]

Thanks I know much more than I did before, and the VoLte sounds good. So when will it be released?

Edited March 13, 2013 by teamgs3

[strumgewr]

Anybody know what the bit rate will be for VOLTE? Just curious.

[MacinJosh]

Anybody know what the bit rate will be for VOLTE? Just curious.

 

According to this article: http://lteuniversity.com/get_trained/expert_opinion1/b/nishithtripathi/archive/2012/09/27/volte-characteristics-a-brief-overview.aspx

 

Adaptive Multi Rate (AMR) speech codec with eight modes uses 12.2 kbps, and AMR wideband with nine modes will use 12.65 kbps.

[JohnnyAwesome]

Thanks I know much more than I did before, and the VoLte sounds good. So when will it be released?

 

That's a bit up in the air, Sprint is going towards 1X Advanced for now which provides increased coverage and capacity, and since VoLTE still has some maturity issues some carriers including Verizon have put off the process for a little while. From my understanding there is some serious battery drain issues.

[teamgs3]

How do they add 1x advance, would dat require a new panel on the tower or something?