< VoLTE >
New horizon for voice revenue
Core Network Planning
VoLTE, an acronym for Voice over LTE, which is based on the IP Multimedia Subsystem (IMS) network, with specific
profiles for control and media planes of voice service on LTE defined by GSMA in PRD IR.92. This approach results in
the voice service (control and media planes) being delivered as data flows within the LTE data bearer.
This means that there is no dependency on (or ultimately, requirement for) the legacy circuit-switched voice
network to be maintained. VoLTE has up to 3 times more voice and data capacity than 3G UMTS and up to 6 times
more than 2G GSM. Furthermore, it frees up bandwidth because VoLTE’s packets headers are smaller than those of
What is VoLTE ?
q In May 2014, Singtel introduced the world's first commercial "full-featured" VoLTE service in Singapore, initially
only in combination with the Galaxy Note 3.
q In June 2014, KTshowcased the world’s first cross-border roaming services based on Voice over LTE. The South
Korean operator partnered with China Mobile to develop VoLTE roaming services.
q In October 2014, China Mobile, KPN and iBasis have successfully implemented the first international VoLTE
roaming between mobile operators based on IMS local breakout architecture with a home routing systems.
q In November 2014, Verizon and AT&T have announced the companies are enabling VoLTE-to-VoLTE
connections between their respective customers. VoLTE interoperability between Verizon and AT&T customers
is expected to be available in 2015. Testing and design are being done between both companies using third
party networks such as Alcatel-Lucent.
q In 11 July 2015, SEATEL Cambodia have announced the world's first commercial 100% VoLTE service without
2G/3G in Cambodia.
q On 16 September 2015, Telstraannounced that they had started enabling VoLTE across its network, including
calling to National Broadband Network and business and enterprise services with HD handsets.
History of VoLTE
MME – Mobility Management Entity
HSS – Home Subscriber Server
PCRF – Policy and Charging Rules Function
CSCF – Call session Control Function
BGCF – Breakout Gateway Control Function
MGCF – Media Gateway Control Function
MRF – Media Resource Function
VoLTE Deployment Challenges
q VoLTE Core & Handset : The successful roll out of the high definition HD voice and video calling service that
promises high quality data and clearer voice calls requires VoLTE technology to be simultaneously available
within the mobile network core as well as in mobile handsets. At this point, most mobile operators’ core
infrastructures are not fully equipped to simultaneously support circuit-switched and packet voice. In
addition, VoLTE-enabled handsets are not widely available today.
q Economy: VoLTE promises to move wireless calls from the legacy circuit-switched network to the all-IP-based
LTE network, but the formidable task of supporting both switched-circuit and packet-based technologies is
not economical for mobile operators in markets where LTE is not yet deployed.
q Roaming: Mobile operators have not completely fleshed out VoLTE call interoperability issues to support
customers who are roaming.
q LTE & Small Cell deployment: VoLTE’s successful deployment depends heavily on nationwide deployment of
LTE technology and the adoption of LTE-based small cells for in-building voice enhancements. At this point,
the adoption of LTE-based small cells for residential and enterprise applications is still very low.
VoLTE Migration Scenario
OTT VoIP vs VoLTE
NSN Smart Labs recently tested both, OTT VoIP and VoLTE and found that in all 5 measured KPIs VoLTE is better:
1. Smartphone battery use
VoLTE clients consumed approximately 40% less than OTT VoIP clients.
2. Data connections
OTT VoIP clients generated up to 10x more data connections in the mobile network than a VoLTE client during a call.
3. Data volume/throughput
Most OTT VoIP applications required between 20% and 40% more throughput than VoLTE clients during active calls to
achieve this quality level, although one OTT VoIP application showed exceptional performance and came close to VoLTE.
Overall data volume consumed over a period of time, including a mix of active and stand-by periods, resulted in at least
50% lower consumption for VoLTE thanks to its more efficient behavior during stand-by.
4. Signaling load
Typical default OTT VoIP keep-alive patterns activated during standby created between 100% and 200% higher signaling
load on LTE networks compared with VoLTE.
5. Mouth-to-ear Delay
The VoLTE client exhibited up to 94% lower mouth- to-ear delay compared to OTT VoIP.
OTT VoIP vs VoLTE
NSN Smart Labs report showed clear advantages to VoLTE in battery, bandwidth and signaling consumption.
These tests, however, were conducted under ideal radio conditions with no network load. The Smart Labs team was
curious what the results would be with a more realistic scenario. To find out, the team tested both services again –
but this time placed the system under various non-Guaranteed Bit Rate (GBR) loads, including best-effort services
such as file downloads, e-mail and Internet browsing, and with poor radio conditions. It turns out that VoLTE voice
quality is not affected at all by non-GBR traffic
Revenue Challenge for MNO’s
q Large Investment in LTE infrastructure
§ Investment Recovery Largely via Broadband Data Plans
q But Revenue needs to grow Beyond Data Plans
§ Supplement via VoLTE, RCS, VAS
New Revenue Stream on VoLTE
1. You gain more capacity for data and voice, using existing spectrum.
A VoLTE network has up to 3 times more voice and data capacity than 3G UMTS — and up to 6 times more than 2G GSM — and that extra
capacity helps you sell more data services. Nearly everybody understood that part. What most didn’t know is that VoLTE’s packet headers
are smaller than unoptimized VoIP/LTE, so that more bandwidth is available for data services. For instance, in a cell with 200 VoLTE calls,
4.4 Mbps is freed up for data services.
2. VoLTE encourages your customers to use more data.
Forget about charging more for voice or RCS. Rather, VoLTE allows your enterprise and consumer customers to easily use 4G LTE data
services by maximizing their time on LTE. This difference helps business employees stay connected and work at LTE speeds. For example,
they can keep their existing laptop or tablet, tether it using WiFi or Bluetooth to their VoLTE smartphone, and talk & work anywhere,
without the old desk phone’s limitations or ongoing operational costs. Consumers can multi-task, talking and browsing simultaneously. As
a result, VoLTE fits perfectly into today’s demand for faster mobile broadband.
3. You can offer rich IP communications right now, including video calling and content sharing.
Video provides engagement and immediacy. It’s as easy to use as voice or messaging, so your customers can use it for closing sales call
without the hassles or variable clarity of OTT video. And content sharing helps your customers use media (files, pictures, videos, location,
etc.) just as simply and broadly as texting. Instead of heading over to email or DropBox, simply move the content within the call itself,
whether it’s to your fishing buddy or to your conference call.
4. VoLTE sets the stage for distinctive apps and services.
You can also develop a full portfolio of differentiated applications and services that give you a competitive edge. For example, multi-device
services offer an attractive differentiator. They make subscribers’ IP communications accessible and consistent from any suitable device,
such as a tablet, even when their smartphone isn’t within reach.