Underappreciated and underrated, voice over LTE is here

VoLTE is still a voice product, but recent developments show how easily it can offer much more to enterprises

Apple is not known for its adoption of cutting-edge, unproven technology. So it’s support of voice over LTE is ironic. Ironic, because VoLTE, as it is also called, is something of a sleeper connectivity standard for consumers, and even for businesses, that is only now beginning to show its promise.

Apple first made it available in the iPhone 6, supporting voice and data streams at up to 150 megabits per second. The company also appears to be adding VoLTE support to its next-gen wireless headset, according to a report in Patently Apple.

 VoLTE's footprint, however, is poised to go much deeper and wider than Apple's audience, as huge as that is. 

VoLTE is a standard that supports the routing of voice traffic over the 4G LTE networks that carriers are currently using to transmit data. Its benefits include providing better-quality voice calls and the ability to use both voice and data at the same time. It also provides better network efficiency, making it more likely for carriers to encourage and invest in its adoption.

While this sounds more like a telecom strategy aimed at consumers, businesses should be watching its approach as well. VoLTE is admittedly still a voice product, a technology that businesses and consumers have pretty much nailed down. But it has the potential to offer much more — and it is becoming a reality much faster than 5G, which, let’s face it, is not even an established standard yet.

Of course 4G’s path to mainstream use — the standard on which VoLTE is based — was not exactly a straightforward line marked by transparency and sincere marketing by carriers. So it is understandable if some distrust might still be lingering.

A brief history of 4G’s broken promise

Just to put VoLTE into context, a brief overview of 4G is necessary.

In March 2008, the International Telecommunications Union-Radio communications sector (ITU-R) rolled out the requirements of the 4G standards. Called the International Mobile Telecommunications Advanced (IMT-Advanced) specification, these standards set the speed requirements for 4G service at 100 megabits per second for high-mobility communication and 1 gigabit per second for low-mobility communication.

It came in two different variations: mobile WiMAX, and LTE, or long-term evolution.

However,  as carriers rolled out services that were branded as 4G, . A few years later, the organization decided to wave these services across the finish line anyway, tacitly acknowledging that while they didn’t fulfill the IMT-Advance requirements, they were still beyond 3G and thus could be called 4G “provided they represent forerunners to IMT-Advanced compliant versions and a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed.” 

Mainstream LTE

That is ancient history, though, as indeed, the iPhone 6's 150 megabits per second support shows. Today, according to an ITU blog post:

LTE is mainstream and fast developing with approaching 350 live networks today, and is expected to cover 70% of the world’s population by 2020. Worldwide the number of mobile subscriptions grew 6% over the last year, while mobile broadband connections leapt 30% to 2.5 billion, of which 350 million are LTE users.

A new report by Signals and Systems Telecom also points to the standard’s growth.

It estimates that VoLTE service revenue will grow at a CAGR of 36% between 2015 and 2020 and that by the end of 2020, VoLTE subscribers will account for nearly $120 billion in revenue. Although traditional voice services will constitute a major proportion of this figure, over 12% of the revenue will be driven by video calling and supplementary services, it said in the report.

Already Verizon Wireless has about 4 million customers using its VoLTE service, according to FierceWireless, citing a speech that COO David Small recently gave at the Oppenheimer Technology, Internet & Communications Conference.

“[I]t is the first time Verizon has disclosed how widely VoLTE has been adopted on its network,” FierceWireless said.  T-Mobile has about 8.4 million VoLTE users as of July, it also report, up from 2 million at the start of 2015.  

To date, it has not been feasible for carriers to offer VoLTE and related services, such as video calling and rich communications, to businesses, largely because their back end IT infrastructure was not able to support such endeavors and still maintain quality performance.

But lately, even as recently as within the last few months, quiet breakthroughs have been made.

 Bubbles of 4G

It started earlier this year at the Mobile World Congress in Spain when Quortus, a U.K-based software provider of mobile core network functionality, unveiled a cellular product for first responders and military operations called ECX Tactical.

It is based on Quortus EdgeCentrix technology, which embeds core network functions directly on a 4G radio system-on-chip (SoC). The system is then coupled with a 4G or WiFi UE for backhaul and cell-to-cell communication, delivering localized voice over LTE (VoLTE) calling, multicast/broadcast communication, ad-hoc node meshing and traffic relaying between vehicle nodes, Quortus explained.

The small footprint of ECX Tactical makes it ideal for deployment in next-generation emergency service requirements in vehicles, un-manned drones or even in a back-pack. It allows the creation of 'bubbles' of 4G coverage, with each bubble able to move and 'mesh' with adjacent nodes, creating larger, resilient and sanitized private communications networks for key personnel, exactly where and when they are needed.

A Virtualized VoLTE Platform

Then a few service providers began rolling out virtualized VoLTE offerings that do support the services that enterprises need.

In February OpenCloud, a cloud-based company that targets the service-layer, reported that its virtualized VoLTE application server was used in the world’s first demonstration of a fully virtualized VoLTE stack on Telekom Austria Group’s live network.  Their pitch that day, not surprisingly, was that "virtualized VoLTE is ready for prime time."

In July 2015, Vodafone Italy also unveiled a similar offering.

Next up is LTE broadcast

Presumably enterprise ready cloud offerings will be making their way into other markets as well this year and next. As they do, let’s look at what else VoLTE can do.

ITU, in its blog post, also highlighted LTE Broadcast (or LTE Multicast) as a “key and promising technology” that is already standardized within 3GPP LTE Release 9 that can support the predicted explosive growth of video services consumption.

The evolved Multimedia Broadcast Multicast Service (eMBMS) is the name of the LTE Broadcast technology and enables efficient distribution of point-to-multipoint content so that multiple users are able to receive the same content simultaneously. It could include HD video, mobile TV, digital radio, or push content.

LTE Broadcast creates a single frequency network (SFN) using part of an operator’s existing LTE spectrum to distribute broadcast streams into defined broadcast areas. All cells contributing to an SFN send the same data during the same timeslots to appear as a single cell. This is particularly useful for serving densely populated areas such as a sports stadium, arena, concert hall, shopping mall, etc. The SFN coverage area may be small, consisting of a few cells, or large – citywide, regional and even nationwide. Multiple users “tune-in” to the SFN for the best experience of the data stream content/service such as video, and in the most efficient way, allowing the operator to free up more capacity for other users on the network, and for more content and services. Broadcast and unicast radio channels co-exist in the same cell, sharing capacity and available radio resources are dynamically assignable for either broadcast or unicast delivery.

Saving carrier Wi-Fi

There is one other advantage that VoLTE will offer businesses, indirect though it may be.  VoLTE also allows mobile operators to refarm their legacy 2G and 3G spectrum offerings. For that reason, LTE will be able to save the carrier Wi-Fi market, according to a blog post by Joe Madden, a principal analyst at Mobile Experts LLC

He writes that the carrier Wi-Fi market isn’t healthy, and major changes in the business model are necessary. “MSOs cannot continue spending billions of dollars per year for Wi-Fi equipment without a bigger stream of dollars coming in.” One solution is for carriers to tie into the LTE market, which would give carrier Wi-Fi a good ROI.

“Today, more than 70% of mobile data is actually carried by Wi-Fi over the unlicensed bands. By 2020, more than 90% of data will be unlicensed, and the cost avoidance of LTE offloading will easily justify the cost of Wi-Fi infrastructure." He figures that by spending about $2 billion per year on Wi-Fi equipment, the industry can save $10 billion or more in LTE equipment.


Copyright © 2015 IDG Communications, Inc.

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