Voice and SMS over LTE

Dreaming over voice over LTE

Back in 2009, as the anticipation for LTE was building, some companies in the mobile industry started a campaign to address a minor, oft-overlooked hole in the migration to LTE – telephony. 

As is well known today, as an all IP packet environment, LTE was intentionally designed to *not* support any of the ‘old’ circuit voice/SMS services.  The idea was to ________ (fill in the blank:  encourage? force?  coerce? incent?) mobile operators to invest in a entirely new, duplicate voice/SMS core infrastructure.  

One group, dreaming of a bucolic, ‘lazy river’ approach to network transformation, created the VoLGA Forum.  The VoLGA Forum embraced a pragmatic approach toward evolving to an all IP access network:   harness an existing 3GPP specification to bridge the old circuit voice system onto the new LTE network and giving time for the brand new all-IP voice system to mature. 

And there was a different dream - more dramatic, more pizzazz , more of a ‘leap of faith’.  Leave the old circuit network behind and we'll all jump with full faith onto the new, as yet undefined (at the time) system.  

Well, reports are coming back from the LTE World Summit, held this week in Barcelona, that perhaps the ‘leap’ is a bit longer than anticipated – a lot longer.  

The problem, of course, is that LTE is actually optimized for VoIP.  And without their own VoIP product, mobile operators are simply encouraging consumers find their own alternative VoIP service.  

"If you haven't built the perfect data network for OTT players, then you have more time," said Ove Andreasen,director of mobile systems for Danish operator TDC A/S  stated during the LTE event.  "You could argue we're too late now if they stay as strong as they are."

Looks like we'll have to dream a little longer...

Wi-Fi - the lowest cost RAN

Mobile operators continue to be under incredible financial pressure.  Revenue per minute of voice continues to decline while new over-the-top apps like Pinger and WhatsApp are eroding SMS revenues. 

Meanwhile, mobile data usage is skyrocketing, but as many industry analysts point out, the revenue per megabit isn’t keeping up with the capital investments required to support the demand. 

In short, demand is up while revenue is down.  It sounds like the “Internet Economy” has struck the mobile industry. 

In response, operators are aggressively moving into new technologies like LTE.  The primary driver for moving to LTE is that, as a transport, it’s significantly less expensive than UMTS/HSPA. 

What other ways can operators wring costs from the network? 

It turns out that 50% or more of mobile data usage happens indoors, specifically at home and in the office.  Of course, those locations are blanketed with Wi-Fi.  

Today many subscribers are turning to Wi-Fi in the home to supplement their mobile data needs.  Mobile operators are encouraging this behavior with price caps that force consumers to look for Wi-Fi to get their mobile data fix. 

But in this capacity, Wi-Fi isn’t actually adding benefit to the mobile operator’s core network services other than to push subscribers off.  Wi-Fi is still regarded as a dumping ground for mobile data that operators can’t monetize. 

However, Wi-Fi can function as an extension to the macro radio access network, actually boosting the subscriber’s mobile coverage and adding capacity where subscribers need it most – indoors. 

By delivering the same experience between LTE and Wi-Fi, mobile operators can embrace Wi-Fi as a new low-cost RAN, while deriving increased offload benefit and improved customer satisfaction through improved coverage. 

Extending the core LTE voice and messaging applications (VoLTE) over Wi-Fi ensures subscribers get a consistent experience over Wi-Fi and LTE. 

Rather than dragging Wi-Fi along to carry un-profitable web traffic, mobile operators can harness the technology to become the in-building radio access network – providing a better user experience, particularly indoors, at a lower cost than LTE. 

 

 

 

VoLTE + Wi-Fi = LTE Femto

This week, Kineto announced it now supports the GSMA’s VoLTE profile (IMS voice & SMS) in its Smart Wi-Fi client.  Smartphones with the Smart Wi-Fi client will now be able to receive the mobile operator’s voice/SMS service (VoLTE) when attached to Wi-Fi. 

I have always believed LTE and Wi-Fi were two sides of the same coin – both are high-speed, low-latency flat IP networks.  LTE covers the macro/outdoor world, and Wi-Fi is by far the dominant in-building wireless technology.  Marrying the two technologies into a seamless experience delivers a compelling experience for mobile subscribers. 

In the move to LTE, mobile operators are adopting VoLTE, an IMS/SIP-based voice and SMS profile that replaces (replicates?) the existing circuit voice/SMS services used in GSM/UMTS networks. 

As mobile voice/SMS account for well over 50% of mobile operator revenues, ensuring these capabilities are available on LTE is critical.  So extending VoLTE to Wi-Fi just makes sense.

A smartphone at home (or in the office) will want the same high speed experience as the outdoor LTE network, and Wi-Fi, already deployed in >400m indoor locations around the world, is ready to deliver. 

This got me thinking:  What, if any, is the role of an LTE femtocell? 

Femtocells, mini base stations designed for home use, have turned on hard times lately.  Yet there is some talk of resurgence as the industry moves to LTE – the logic being that LTE networks will be patchy for the time being, and an LTE femto to boost in-home coverage will help accelerate adoption. 

But let’s consider the role of a 3G femtocell today, and see if it applies to an LTE deployment/subscriber.  A 3G femtocell provides a strong 3G signal in the home, boosting coverage.  But really this amounts to a subscriber having access services that reside in the mobile core network – namely voice & SMS.  Sure there may be mobile data services like MMS, Mobile TV, or Visual Voicemail too, but the bulk of the interest, and revenues, are associated with voice/SMS. 

In the move to LTE, subscribers will still want to make a phone call, so access to voice/SMS is critical.  With Kineto’s Smart Wi-Fi client, smartphones can access VoLTE over Wi-Fi directly, no LTE femtocell needed. 

As for mobile operator data services, many are being adapted to the new ‘all-IP’ world.  Apps are able to directly access mobile data services over any IP network rather than only from within a mobile RAN. 

It seems that Wi-Fi, when paired with VoLTE over Wi-Fi, delivers the same experience as an LTE femtocell.  Access to internet services (Facebook, YouTube) happens directly over Wi-Fi.  And Smart Wi-Fi with VoLTE support delivers calls/texts via Wi-Fi.

Let me know what you think.  Can an smartphone that provides VoLTE over Wi-Fi remove the need for an LTE femtocell?