By Anne Morris
Voice over Wi-Fi is nothing new. Indeed, it has been around for a long time considering the prevalence of traditional voice over IP (VoIP) applications such as mobile Skype as well as the newer kids on the block that have leapt onto the over-the-top (OTT) service bandwagon.
From the perspective of a mobile operator, the "problem" they have traditionally faced with such VoIP and OTT services is that the operators are not in control. Indeed, fears of what such services could do to an operator's business model prompted many to block VoIP in the early days, and there are still instances of this in the small print of some pricing plans.
Operator concerns about the impact of OTT services were well founded. Voice and text revenues were cannibalised by trendy new ways of making calls and sending messages via smartphone apps. In the wake of this, many operators decided that if they could not beat OTT players, they could at least join them.
Different VoWiFi approaches
Current Analysis analyst Peter Briggs places "VoWiFi" approaches by operators into three broad categories. The first largely includes responses to Skype with peer-to-peer calling and messaging services, such as Orange's Libon service. The second includes downloadable applications such as Three's InTouch.
Now, the next generation of Wi-Fi calling -- where the service is embedded in the smartphone and accessed via the normal phone dialler -- is offering operators a way to take back control by enabling them to provide voice services in areas where they have little or no coverage due to poor signal strength.
"It's cleaner and more simple, without the off-putting step of downloading an app," said Briggs. "Integrating it into the phone is the trend we see a lot. It has been available as a feature of Android for a long time. Now, it's also supported by iOS."
There are some advantages of the app-based approach, however.
"This means that it can be used on any smartphone," said Kester Mann, network operator specialist at research firm CCS Insight. Integrated Wi-Fi calling is currently only available on high-end smartphones.
Indeed, Three UK noted that the Three InTouch app is available on any iOS handset running version 6.0 and above or any Android handset running 4.0 and above.
Three's InTouch app is how the operator is approaching Wi-Fi calling.
"Therefore, rather than a service that runs on a few selected devices, we offer an app that is available to the vast majority of our customer base," a Three spokesperson said.
Factors such as the support of Wi-Fi calling by Apple iOS 9 and the perceived success of the T-Mobile US service launched in 2011 are nonetheless prompting a growing number of operators to launch dialler-integrated Wi-Fi calling services (T-Mobile US has offered Wi-Fi calling for free since May 2011 but has offered it since 2007, when it debuted its [email protected] Wi-Fi calling service, which relied on technology from partner Kineto Wireless).
Vendors are also getting in on the act. In September, Ericsson extended its Wi-Fi calling service to include non-cellular devices including tablet and desktop PCs, for example.
Benefits of native Wi-Fi calling
Not only is the service being rolled out to enable operators to offer voice services in locations where mobile signals are weak, it could also ultimately let carriers support call handovers between Wi-Fi and LTE networks once Voice over LTE (VoLTE) services are also available.
EE became the first operator in the UK to roll out Wi-Fi calling as a dialler-integrated service, although Three UK has been offering the Three InTouch app and O2 the TU Go app for longer. In October, EE said its Wi-Fi calling service had 1.7 million activated users with more than 125 million Wi-Fi calls made since the launch in the first quarter of this year.
According to Tom Bennett, director of network services at EE, "Wi-Fi calling is a way for us to expand the reach of our network, without customers needing to use a new service or be limited to a closed user group, like with OTT services."
EE's strategy with Wi-Fi calling was first and foremost to limit churn by offering "a prioritised carrier grade service" in the home, providing coverage where it had not been available before.
Although EE has embraced Wi-Fi calling the operator is not going to throw its support behind Wi-Fi for other functions such as data offloading. "That part of the thinking has not changed," Bennett said. "We would still say the data experience is better on LTE. We don't want to offload traffic."
Cloud and mobile communications specialist Mitel has been involved with the VoWiFi launches of operators from T-Mobile US to Three UK and EE, and has also carried out a number of trials with cable operators and non-traditional mobile operators investigating the "Wi-Fi-first" model.
However, Terry McCabe, the CTO of the company's mobile business unit, said mobile operators looking into extending coverage are the first to launch services.
Mitel's Terry McCabe
As demonstrated by EE, McCabe said the theory around Wi-Fi calling today is more about coverage extension and less about mobile operators embracing a Wi-Fi footprint.
"Carrier Wi-Fi is for the non-traditional players such as large cable operators," he said. For the traditional wireless operator, Wi-Fi calling is a something of a red herring for carrier Wi-Fi, he said, adding: "Wi-Fi calling is low cost. If they had to go through the cost of carrier Wi-Fi, it defeats that purpose."
Alix Pryde, head of consumer services and innovation at Vodafone UK, also said Wi-Fi calling is a way to deliver services to customers where it is very difficult to provide a mobile signal. She noted that the operator chose to launch a dialler-integrated service rather than take the app-based approach because services "should make a customer's life easier, not complicate it."
"We made the decision early on that our service should be integrated into devices in order to make the service as seamless as possible to use," Pryde said. "Integration of the service rather than creating an app was more difficult to achieve but provides a far better customer experience, we believe."
Pryde added that Vodafone UK is encouraged by the early feedback it has received about the service.
Three UK chose the app route, launching Three InTouch in July 2014. The company said 1.44 million people were using the app as of September 2015, and also noted that the volume of network-related complaints fell by 32 per cent between November 2014 and September 2015.
"We're looking at an embedded version of the app but there is no timeline yet," the company added.
Moving toward VoLTE
Three UK has nonetheless been the first in the UK to launch VoLTE, which is also essential for the future of voice handover between a Wi-Fi and mobile network.
EE's Bennett said VoLTE will keep customers on 4G, "even when they're making calls, that's the main benefit. As well as that, it will enable handover between 4G and Wi-Fi for Wi-Fi calling."
Vodafone's Pryde said the operator "continues to make progress on 4G voice and we have now moved it from our labs for rigorous testing on our live network. We will provide a further update on our launch plans soon."
Bennett added that EE would make VoLTE available to its customers when the reliability of the service is as good as its current voice service. "We're happy to be a fast follower with VoLTE and launch only when the quality is right. We can get VoLTE to a dropped call rate of just 0.1 per cent, but it's not there yet and voice is the thing on our network we have to protect most."
Swisscom is in fact the first operator in Europe to offer both Wi-Fi calling and VoLTE, noting that VoLTE is switched on by default while Wi-Fi calling has to be enabled by the customer. A Swisscom spokesman said its network supports handover between the two services, but not all devices do.
"Apple devices support it already, others will be following soon," the spokesman said.
A recent report by Briggs at Current Analysis said more carrier offers of VoWiFi services are expected as operators in all regions move towards better coverage with richer communications services.
"Handover between it and VoLTE and dialler integration will not only give the carriers an edge over the OTT apps, but will help them explain why carrier VoWiFi is not quite 'free'," he said.