Carrier WiFi

Can WiFi Calling Find Its Voice?

As expected, the UK gained its first "integrated" WiFi calling service last week courtesy of mobile giant EE. The surprise was that it first became available on a selection of iPhone models -- those being the iPhone 6, 6 Plus, 5S and 5C -- after Apple raced out a software upgrade supporting the new feature on April 8. Only a day earlier, EE had informed the industry the Lumia 640 and Samsung's Galaxy S6 would be its inaugural WiFi calling devices. (See EE Hopes WiFi Calling Will Hit the Spot.)

As fortune would have it, your correspondent's wife had acquired an iPhone 6 on an EE service plan just days earlier, giving Light Reading an immediate opportunity to test drive the WiFi calling service. With mobile operators starting to prioritize service quality as a competitive differentiator, the big question is whether WiFi calling is likely to give EE any kind of advantage over its rivals.

The first thing to say is that upgrading the iPhone 6 to support WiFi calling involves nothing more than a standard software upgrade, with which any iPhone user will be familiar, followed by a couple of tweaks to settings. After those changes have been carried out, a small "WiFi calling" icon appears at the top of the screen to indicate that calls will automatically run over WiFi in preference to cellular.

Before I go on, I should note that despite living in a densely populated London suburb I struggle to obtain a signal on EE's network (using my iPhone 4S) in parts of my home, which is where I work (calls to my mobile are often diverted to voicemail when I am indoors). I have occasionally surmised that EE's lack of non-4G sub-1GHz spectrum is to blame. (My editor-in-chief thinks I'm avoiding him.)

So far, the WiFi Calling-enabled iPhone 6 appears to have picked up every call made to it. Moreover, when calls do get through on the cellular network, it is usually hard to make out everything a caller says. In the living room, where the WiFi router is stationed, that has not been a problem using WiFi calling.

Unfortunately, EE's WiFi calling service does not yet support handover from WiFi to cellular should a customer move outside the hotspot. As a result, when I tried migrating from the living room to the bedroom, where the WiFi signal is relatively weak, the call I was on failed. Handover does not work in the other direction, either. So if you receive a call on your way back home, you're better off finishing it before you arrive.

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My own circumstances notwithstanding, EE insists that WiFi calling is largely aimed at customers in rural communities where cellular connectivity remains weak. Yet in some of the remotest parts of the UK, the lack of fixed-line broadband services seems a bigger problem than patchy mobile coverage. Indeed, both government and industry representatives have argued that mobile technology is an economical means of providing broadband services in such areas. In other words, the rural customer who can't get a mobile signal indoors may not have a WiFi router to fall back on.

Does that mean EE really hopes to address a more widespread coverage problem that stems from its shortage of sub-1GHz spectrum? In the US, T-Mobile US Inc. has been quite forthright about its indoor-coverage shortcomings, blaming these on its own lack of low-band airwaves. Its rollout of a new WiFi calling service in September was widely perceived to be a stopgap until it had built up its sub-1GHz holdings. (See T-Mobile Turns Up VoLTE-to-WiFi Handoff.)

Spectrum Holdings of UK Operators
Source: European Communications Office
Source: European Communications Office

Priding itself on its technical prowess, EE would fiercely resist making any such admission. In rural Oxfordshire, however, it has been running trials of voice-over-LTE in the 800MHz band, which might give it a more robust means of providing decent coverage indoors as well as in rural communities (that is, without the handover problem that affects WiFi calling). (See 3 UK to Launch VoLTE by September.)

In the meantime, EE may have some work to do on pitching WiFi calling to customers. Promote it as a "rural" service and the operator could miss the bigger opportunity, assuming my experience is not unique. But suggest that WiFi calling might appeal to customers like me, and EE risks drawing attention to a possible weakness.

What's more, given that WiFi calling holds few other obvious attractions, customers could be disappointed. When I told my wife about the service, she first asked if it would allow her to call family and friends overseas "free of charge," in the manner of Skype Ltd. Yet despite piggybacking on fixed-line services, it actually counts usage against the normal monthly allocation of voice minutes. For customers who are not technically minded but familiar with the concepts of over-the-top services and Internet telephony, this could seem like a poor deal.

WiFi calling may be a hard sell.

— Iain Morris, Circle me on Google+ Follow me on TwitterVisit my LinkedIn profile, News Editor, Light Reading

mhhf1ve 4/14/2015 | 4:40:22 PM
Re: This is an app for me... "This service blurring the line between WiFi and cell networks ..."

This. I think it's a bit of a mistake to confuse customers with cell and WiFi calling because then any call quality issues on the Wifi networks (which has nothing to do with the cell network provider) can be blamed on the cell provider. I suppose if the Wifi network is actually MORE reliable and higher quality than the cell provider's network, it could actually benefit the cell provider, but.... 

And then, as you point out, there are other unintended consequences with roaming charges, etc.. as users are sorta tricked into thinking their coverage extends beyond where it actually goes.

I also think other carriers that don't necessarily need to employ VoWiFi features might use this in attack ads someday. I could see an AT&T ad mocking how T-mo users have to fiddle with WiFi handoffs and dropped calls when going indoors. I think for a while there AT&T had ads that highlighted that people could "surf AND talk" at the same time, so.. any minor advantage is fair game for attack ads. And of course, the "can you hear me now?" guy could always appear again in ads telling people how indoor coverage without using WiFi is just soooo much better.
mhhf1ve 4/14/2015 | 4:30:05 PM
Re: WiFi vs. small cells sowen557,

Exactly right. That's why this is a stopgap measure. For little investment, a carrier can try to offer a slightly better experience by piggybacking on someone else's Wifi+wireline network.

It would be nice to see more carriers gain better spectrum for indoor coverage and truly be able to compete in the mobile space... but for now... this is what we've got.

Mitch Wagner 4/14/2015 | 2:46:56 PM
Re: This is an app for me... mhhf1ve - You raise a good point. When I was in Europe last year I took comfort putting my phone in airplane mode with WiFi switched on, knowing I definitely was not getting dinged for huge roaming charges during that time. This service blurring the line between WiFi and cell networks could result in unanticipated charges, alienating customers. 
Mitch Wagner 4/14/2015 | 2:40:08 PM
Re: WiFi vs. small cells sowen557 - "Isnt this a cheaper option than Small Cell in low ARPU markets?"

Good point, particularly considering the WiFi AP is likely to be BYO equipment for the consumer. Carrier doesn't have to pay to provide it -- consumer picks up the tab. Or somebody else if the consumer is out roaming, using WiFi at a retail establishment or whatever. 
brooks7 4/14/2015 | 9:04:33 AM
Re: This is an app for me... Back when T-Mobile was running real UMA I could do handoffs without drops. With wifi calling today I choose cell preferred unless I am outside the U.S. Thus my phone does not switch. Seven
sowen557 4/14/2015 | 7:09:48 AM
Re: WiFi vs. small cells Isnt this a cheaper option than Small Cell in low ARPU markets?
mhhf1ve 4/13/2015 | 7:44:06 PM
This is an app for me... I'm not sure I really want my cell and WiFi calling capabilities combined on my smartphone. I have an app that can do Wifi calls, and I kinda like how it's separate from my regular cell calling user interface, so that I know it'll fail when I leave the Wifi network. When it's all combined -- it seems like service providers run the risk of users confusing dropped calls from a Wifi-cell handoff that doesn't work to their cell provider.

I think these stopgap measures should be replaced with more effective spectrum auctions that allow for more competitive wireless carriers in the US..... :P
milan03 4/13/2015 | 2:08:49 PM
Re: WiFi vs. small cells In the U.S. T-Mobile fully supports VoWiFi <-> VoLTE handoffs, both leveraging HD Voice at 23.85kbps.

In order for this to happen, a wireless operator needs to make an investment into ePDG on the network side, in order to provide this seamless end user experience.
Mitch Wagner 4/13/2015 | 11:47:23 AM
WiFi vs. small cells Sounds like WiFi calling is a stopgap measure, and small cells are the wave of the future for plugging coverage gaps. 
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