Wi-Fi Calling. Is it ready for prime time?

Wi-Fi calling presents a great deal of opportunity and a lot of risk for service providers. For consumers it’s a no brainer, offering higher service availability, network transparency, one contact list and savings on cell minutes– more calls for less with greater convenience, why would anyone not want it? Actually, it is what consumers have wanted all along since Wi-Fi became ubiquitous in the workplace and home.

There are lots of free VoIP and IM tools out there: Skype, Yahoo Messenger, Google Hangouts, Viber, WhatsApp, Facebook, WeChat and dozens more. But in most cases you can only reach other members, or must pay additional fees to reach “off-network” phones. You can’t reach anyone and everyone on their phone. But phone-to-phone with no changes in behavior, that’s what people want – that’s compelling, and if free to boot – that’s a no brainer reason to change operators to realize this calling feature.

So service providers are scrambling to make this feature available and to convert their own customer base to use it, before a competitor does. Service providers that fail to deliver Wi-Fi Calling promptly could face massive subscriber churn, but on the other hand, how can this be good for them? Wi-Fi Calling adds another twist to an already complicated Wi-Fi monetization strategy and requires additional technology to do right.

How will Wi-Fi Calling be monetized?

For now it seems that most operators will offer Wi-Fi Calling as a free option that doesn’t use cellular voice or data minutes. A logical conclusion is therefore that users won’t consume so many cellular minutes, and this begs the question: “how do the MNOs make money?” It turns out this may be a false assumption. If the call terminates on a cellphone or land line, you can expect this to count as a cellular call. So, in all likelihood, cellular minute consumption may not go down at all, even though many calls will now originate on Wi-Fi. Service Providers do benefit, indirectly, by freeing up access capacity in their network, while still generating the same call revenue.

Overall consumption will actually go up because it just got easier to talk to your BFF for free. Will it be enough to switch texters to voice when both parties are on Wi-Fi? Perhaps not! But it seems plausible that a range of applications might emerge which are enabled by sharing network presence information with people in your “social” network. People’s communication choices are influenced by their cost. If I knew it would be completely free for all participants, I might be much more inclined to video chat on my phone, than if I knew one of us was limited to cell coverage and would pay dearly for the stream.

If it turns out service providers are losing money as a result of free Wi-Fi Calling, we can expect them to change tactics and charge for it within plans, as some already do with global roaming. Time will tell. Either way, resorting to cheezy ad-insertion into voice calls may not go down so well! So Service Providers need to find new ways to wrap services they can monetize around calls, and that requires good backend technology. For now it is too early to tell precisely how service providers will monetize it, but whether they will roll it out or not, is clear.

Leading operators all committed in 2015

Wi-Fi Calling support in Apple phones since iOS 8.3 has been a great catalyst. In the short time that Wi-Fi Calling has been in the limelight, a number of notable mobile network operators in the US and Europe have already launched services albeit in limited footprints. 2015 has certainly been the year of announcements. As of Oct 2015 T-Mobile, Sprint and AT&T all have operational services. MVNOs Republic Wireless and FreedomPop make Wi-Fi Calling the default on their “Wi-Fi First” configured phones.

In the EU too, Wi-Fi Calling has suddenly become a must-have service offering, with Telenor Sweden, Vodafone UK and EE all launching services earlier this year. BT is paving the way there with SmartTalk, more expected from them shortly. And O2 is part of the way there with its OTT app Tu Go. Whether it is native Wi-Fi Calling or an OTT app, we expect the scramble to ripple across service providers worldwide at a rapid rate. The technical implementation for Wi-Fi Calling might seem easy but in the fullness of time additional technologies including seamless roaming, and session-level control will be required to provide the desired user experience, and to lay the foundation for a host of related OTT applications. So there remains a long road ahead.

More technical sophistication down the road

Current implementations of Wi-Fi Calling are pretty rudimentary. A call initiated on Wi-Fi is stuck there, the user can’t leave that area, and roam to another AP (unless it’s part of a network of coordinated APs with seamless session roaming – think enterprise), they can’t go outside and switch to cellular. No, once out of range of that AP or SSID the call will drop. So seamless roaming is top on the engineering agenda. This is tied to network selection and network quality assessment.

To enable more services alongside Wi-Fi Calling, operators need more control over the session. More control would present more monetization options. IP Multimedia Subsystem (IMS) may be the play. IMS has been lurking in the wings of mobile communications for several years, could this be a turning point for IMS too? UK Service provider EE is using IMS in part to manage the call sessions.

Call quality will become an issue

At first users will be content with the miracle that just happened. But not long after, call quality will become an issue. Call quality is always going to be subject to the quality of the Wi-Fi network the user is on. Unfortunately poor call quality on Wi-Fi will reflect badly on the provider’s service, but there is little they can do about the Wi-Fi quality on any random Wi-Fi network. Service Providers may have their work cut out for them, in terms of setting reasonable expectations of service quality of "foreign" Wi-Fi networks.

Republic claims its codec can handle calls in as little as 80K of bandwidth, but other vendors’ solutions may not be so tolerant. Ultimately however, better codecs is not the answer. Better network selection is the key. Solutions will need to proactively evaluate Wi-Fi quality and seamlessly switch the call to cellular, even mid-call if necessary.

Wi-Fi network service assurance

On the Wi-Fi networks that a service provider controls, more can be done to assure optimal voice quality. Service providers should want calls to be made and received on Wi-Fi as much as possible, as this directly reduces the utilization of their cellular network. To this end, the better the Wi-Fi quality their networks provide, the more users will favor Wi-Fi for both voice and data, or if the phone can choose the best network based on projected call quality metrics, the more it will prefer Wi-Fi. Therefore making their own Wi-Fi networks perform reliably should be a priority for service providers. It doesn’t just impact Wi-Fi Calling it affects all their Wi-Fi monetization initiatives.

Here’s the problem. Service providers Wi-Fi networks face the growing interference from adjacent wireless networks they do not control, which is only being exacerbated by the widespread deployment of 802.11ac access points and continued density increases of mobile devices. Wi-Fi networks are being deployed by everyone, everywhere. A stable RF environment one day may be a battlefield the next, because the City decided to deploy Smart street lighting or a Community Wi-Fi network in your previously stable airspace, or another carrier just introduced a LTE/Wi-Fi small cell, down the street, or the business next door just installed a Wi-Fi network with complete disregard to the channel utilization around them.

If you’ve been watching the LTE-U debate, it is abundantly clear that the largest Wi-Fi network operators recognize RF instability is a real and growing threat to successful Carrier Wi-Fi monetization. However the LTE-U debate pans out, automated Radio Resource Management is a first step service providers need to take in order to ensure a stable Wi-Fi environment that would let them commit to and honor voice quality SLAs, and offer OTT Wi-Fi applications which they can monetize.

embedUR’s role in Wi-Fi Calling and Carrier Wi-Fi

With a decade of experience bringing to market embedded systems for networking and telecom products in the wireless, switching, access and mobile domains, embedUR has developed a unique mix of expertise in developing all manner of Wi-Fi technologies to enable service providers to build and operate more profitable Wi-Fi networks.

As the number of connected Wi-Fi devices continues to substantially grow leading to more and more wireless networks being deployed, the effects of interference on real-world performance make it difficult for an operator to enable successful services. Effective and automated radio resource management is a necessity for solving this limited spectrum versus quality issue.

From developing an automated Radio Resource Management system to developing an IMS agent for managing multiple multimedia sessions, embedUR has the experience, capabilities, and products to help you exploit the mobile platforms, the Wi-Fi spectrum and the network to maximize performance and efficiency. Contact us to discuss your project.