Shades of VoLTE

Verizon Wireless and AT&T have both talked up their impending voice-over LTE (VoLTE) launches and how important it is to get the 4G voice technology exactly right first, but they haven't actually said what all their flavors of VoLTE will entail.

At its simplest form, VoLTE just needs to be voice and SMS to be on par with its circuit-switched predecessor. But, the beauty of being an all-IP technology means it can also include a full suite of rich communications services like IM, video chat, HD voice, presence and group chats.

Doug Makishima, COO of D2 Technologies, which provides embedded IMS software to LTE modem and chipset vendors and handset makers, as well as works with a whole host of operators on 4G voice, says the big two operators' strategies for VoLTE deployments will vary.

One is planning to roll out a complete RCS platform, while the other is going to just launch voice and text and iteratively add features on to it. Ever the gentleman, he wouldn't say which strategy went with which.

"One of the two will do a soft launch of VoLTE and then roll out more features later, so they might not make a whole lot of news around the first wave of VoLTE phones," Makishima says. "It'll be normal voice and SMS. On the other hand, we're hearing the other guy wants to have all these new features all together, and that's the advantage of [VoLTE]."

Both AT&T and Verizon say they are getting close to deployment. Verizon reiterated Thursday in its earnings that it would start testing and launch its first VoLTE handsets sometime this year, with a commercial launch next year, while AT&T has said it will go live this year. Makishima says he's more confident that the operators won't push back their launch dates now than ever before. (See Verizon Ups Spend for VoLTE & 4G Video Hogs and AT&T Plans 4G Voice Launch This Year.)

When VoLTE does go live, consumers might not care how robust the voice service is on day one. Most already have their own preferred video and IM clients. And, if operators introduce new free services that improve their voice calling, that would just be a bonus. What they will care about is that their 4G voice service works as well, if not better, than what they are used to.

The wireless operators get this. That's why VoLTE has had several delays and setbacks. They're going to get it right on day one. But, just like a "market" covered with LTE means different things to different operators, just how advanced each VoLTE service is will likely vary as well.

— Sarah Reedy, Senior Editor, Light Reading

gconnery 7/24/2013 | 3:57:42 AM
re: Shades of VoLTE Improved voice QUALITY is what I'm looking for. They can spend all the time they want on video, conferencing etc but I won't be using any of that. Like you say, we've all chosen our partners already and I see no reason to pick something that would lock me into the carrier at this point. Just make the voice quality better. Please please please.

And of course on Verizon I want voice and data on the iPhone...
PS 7/20/2013 | 3:41:11 AM
re: Shades of VoLTE Sarah,
1>VoLTE capable Phone is equipped with SRVCC feature to switch to CS/Legacy domain when it cuts-off from LTE coverage. Network Ensures the call continuity in legacy domain.

2>If the Phone is a single mode dual standby one, Network directs phone/UE to fallback to CS whenever a voice call is initiated.

3>If the Phone is a dual mode-dual standby one, Phone tunes to CS/Legacy whenever user invokes a voice call.

Of the above 3, #1 is the recommended approach and that's what a VoLTE- SRVCC is about. It simplifies radio requirement on the Phone and hence phones are much power efficient. However on the network side, it requires an EPC core and IMS core.
Jerry01 7/19/2013 | 10:27:00 PM
re: Shades of VoLTE Sarah, It will be Verizon that will launch with Full RCS first not AT&T. Verizon will not need a fall back position for voice since they will launch VoLTE across their entire network. They will be completing their 1 for 1 LTE over lay later this year, They will not need CDMA for voice once they have full LTE coverage and customer purchase a VoLTE capable device. The other reason I know this is VoLTE and RCS both use the IMS core. Since these are all IP based services and Verizon will have full LTE coverage it makes sense that it will be Verizon with RCS first. Also I'm just guessing after running carriers for over 22 years that you will not be able to turn off VoLTE as a feature. Once you have a VoLTE capable device it will be better for the carrier to have you on their LTE network to move traffic from the 3G networks to eventually re-farm their spectrum for LTE-Advanced. I would be shocked if the carriers would let you turn off VoLTE. Once you have a device with a chip-set that will support VoLTE the carrier can start working their plans to get traffic off their other legacy networks to re-farm the spectrum.
Dredgie 7/19/2013 | 5:54:53 PM
re: Shades of VoLTE Along with coverage (i.e. the need for SRVCC or CSFB) the prohibitive cost of VoLTE infrastructure has probably limited deployments to date - and will continue to, if operators don't change their models. i.e. the cost of an IMS core, IR.92 TAS, plus session border controllers and their convoluted licencing. It was one of the wake-up calls that lead to NFV – hence being one of the 6 initial use cases. And it’s what’s driving interest in Project Clearwater (the opensource Cloud IMS core + TAS initiative) within the Tier 1’s, etc. Also a vSBC (SBC VNF) w/global licencing (rather than fixed / per hardware box), alone, should dramatically lower costs.
Sarah Thomas 7/19/2013 | 2:40:12 PM
re: Shades of VoLTE Btw, based on comments the two have made and the fact that Verizon doesn't have the circuit-switched fall back capabilities, my prediction is that Verizon is the one starting with plain ol voice and text VoLTE, while AT&T will do a richer service out the gate. I'll update this when/if I hear back from both.
Sarah Thomas 7/19/2013 | 2:24:17 PM
re: Shades of VoLTE That's something I'm a little confused about. If you buy a VoLTE-capable phone, will you have the option to turn it off? You will fall back where LTE isn't available, but I don't know if it'll be the customers' choice which to use. I certainly don't see a lot of people buying a new phone because of VoLTE though.
Jim Crawford 7/19/2013 | 1:57:28 PM
re: Shades of VoLTE Price will be a factor, too. Customers may need an incentive to switch to a new technology until all the hiccups are worked out. Unless the price is right, many may decide that plain old circuit-switched fallback for voice is just fine on their 4G devices -- for the moment.
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