Emergence of mobile HD voice services




By significantly raising the quality of voice communication with
more natural sound and improved intelligibility, HD voice will play a key role
in ensuring that voice continues to offer value to operators and users of fixed
and mobile networks alike.



In the middle of
a data-traffic boom, the way people talk on the phone is changing and
high-definition (HD) voice is a crucial next step in the development of voice
communication technology. Next-generation fixed and mobile networks bring
coverage anywhere and anytime. This, together with smartphones and devices,
creates new opportunities for users to do more with constant connectivity and
mobility. Today’s consumer can use a single device to chat with friends, work,
shop online, pay bills, listen to music, locate where they are and see where
they are going all while on the move.




In recent years,
mobile-broadband traffic has increased exponentially as a result of
developments in network technology and the introduction of new kinds of devices
and applications that take advantage of being connected. In 2009, data overtook
voice as the dominant traffic in mobile networks, and based on growth
predictions for data traffic with data traffic doubling annually over the
next few years the gap between the two will continue to widen.




These figures
may seem to suggest that voice is no longer significant. However, operators
derive 70 percent of their revenues from voice and voice-related services.
Consumer attitudes indicate that even if the relative market share for voice
decreases over time, revenues will remain constant. In addition, studies show
that users appreciate the personal nature of voice communication, and believe
it offers a more familiar, emotional connection to another person than text
messaging, e-mail or social networking.




Operators are,
however, no longer alone in the communication-services market the explosive
growth of over-the-top (OTT) players has introduced new competitors that
provide voice services essentially free of charge. Skype user numbers, for
example, increased to 663 million in 2010, up from 474 million in 2009 a
customer base that could be tapped by traditional operators, with the right
service in terms of quality and price.




Improvements in
the quality of voice communication have been slower to emerge than the progress
made in other areas of communications technology. HD voice, the next step in
the evolution of communication services, is a fully developed and standardized
technology that has already been deployed by some operators, with many more
conducting trials. Users who have experienced this technology consistently say
it feels like they are talking to a person in the same room.




The clarity and reduced interference gained from combining HD
voice with active noise-cancellation technologies and improved device
acoustics, will allow users to make calls in noisy environments, such as near a
busy road, on a construction site or in extreme weather conditions, where
normal calls would simply not be feasible. The technology enables
crystal-clear voice-mail playback, more effective conference calls and better
speech-to-text applications, reducing stress, offering subscribers value for
money and ultimately creating new business for voice-communication services.




One factor in
particular supports the operator business case for HD voice: the user response
to the technology. Studies conclusively show that consumers react positively to
HD voice. On a scale of 1 to 5 (with 5 representing the best quality), users
ranked the quality of calls between HD-voice-capable devices at over 4,
compared with just over 2 for a non- HD-voice call. Having experienced HD
voice, 76 percent of consumers said they would be inclined to switch to a fixed
or mobile device that offered it.




This preference
is natural given the workings of the ear. The range of human hearing covers
frequencies from 20Hz to 20,000Hz and the human voice spans a frequency
range of at least 50Hz to 12,000Hz, but today’s phone calls transfer sounds in
a spectrum band of roughly 300Hz to 3,400Hz. Consequently, the voice quality of
both fixed and mobile calls is limited. For example, the aural information
needed to consistently distinguish F sounds from S sounds is contained in
frequencies that are higher than conventional calls allow. The potential for
misunderstanding is one reason for the development of phonetic alphabets for
use in critical telephone or radio communications, such as air-traffic control.




HD voice, on the
other hand, uses wideband (WB) codecs such as Adaptive Multi-Rate Wideband
(AMR-WB), Enhanced Variable Rate Codec Narrowband-Wideband (EVRC-NW) or G.722
to transfer a much wider band from 50Hz to 7,000Hz resulting in better
quality, more natural sound, and improved intelligibility and voice




The end-user benefits of HD voice are clear: the experience of
changing from ordinary voice is comparable to switching from
standard-definition to high-definition television (HDTV). Operators offering HD
voice are certain to gain subscriber loyalty and enjoy reduced churn.






The improved
user experience encourages subscribers to make more calls, and the average call
duration tends to be longer. Making calls in previously inconvenient
situations, such as from a busy street, is now viable, and the more natural
voice quality relieves the fatigue often associated with longer phone
conversations. One study showed 96 percent of HD-voice users were either very
satisfied or quite satisfied with the service, and 21 percent claimed their
calls lasted longer. Having subscribers who place more calls and spend more
time talking is obviously an attractive prospect for any operator.






Quality is a key
concern for OTT players, who have seen a clear correlation between improved
codecs and increased service usage, and who continue to make considerable
investments in improving user experience. To successfully compete with services
that are essentially free, operators should ensure that the quality of their
voice service keeps pace with this competition. Operator advantages over OTT
offerings including network prioritization and better security count for
little if user experience falls short of expectations.




HD voice helps
operators to keep pace with developments being made by OTT players and how they
differentiate their offerings. The efficiency of codecs suitable for HD voice
ensures that operators can do this without any significant impact on
radio-frequency (RF) capacity. In addition, OTT services are still considered
unreliable, and HD voice can help promote an image of reliability and set
operators apart from their OTT competitors. Operators, unlike OTT players, can
also attract and retain users through packages that bundle HD voice with HDTV
and high-speed internet.






The benefits of
clear, high-quality voice communication are even more tangible for enterprise
users, who have been quick to recognize the potential impact of HD voice in
business-critical areas such as conference calls and the fast-growing
voice-recognition-services market, where better voice quality can lead to
improved efficiency, reduced costs and a more productive working environment.


From an operator
perspective, enterprise demand is one of the strongest pillars of the business
case for HD voice. Once convinced of the merits of a technology, enterprises
tend to buy it in bulk, and it is relatively straightforward to introduce
HD-voice-capable fixed or mobile devices on a departmental or organizational
scale. Enterprise users tend to spend more than private subscribers; this
presents an opportunity for operators to differentiate themselves by including HD
voice in their enterprise packages.






In recent years,
there has been a radical shift in terms of when and where subscribers connect
to the internet. Prior to the mobile-broadband and smartphone revolutions,
consumers tended to use the internet in chunks and confine their online
activities to when they were sitting in front of a computer. Now, smartphones,
tablets and mobile broadband offer subscribers ubiquitous connectivity. A study
by Ericsson ConsumerLab in May 2011 showed that 35 percent of smartphone users
in the US interact with applications on their mobile devices before even
getting out of bed in the morning.




Such individuals
expect to be able to use voice in the same way. Unfortunately, mobile voice
calls can vary dramatically in quality, and in many cases fixed-network calls
are still considered to offer a better experience. The words I can’t hear you
very well; let me call you back on my landline” remain too common in developed




HD voice enables clear, intelligible conversations on any device.
With HD voice, an optimal user experience is no longer exclusive to fixed
networks, ensuring that subscribers consider the quality of mobile voice
services to be on a par with mobile data services. Fixed networks will,
however, continue to be important, and HD voice is highly relevant to any fixed
offering. However, postponing a conversation until a fixed-line connection is
available will soon be a thing of the past.




The first
commercial mobile HD voice service went live in September 2009, and HD voice
has since been launched on 32 networks in 29 countries and territories. Forty
percent of countries in the European Union have commercially launched mobile HD
voice services, or are engaged in trials ahead of their intended introduction,
and test deployments are progressing rapidly in many parts of the world.




Perhaps the most
obvious sign of HD-voice gathering momentum is the number of HD-enabled
handsets on the market, which is more than 50. Many of the latest products are
shipping with HD voice capabilities activated as the default setting. Operators
who have launched HD-voice services have been important drivers of this
process, and as more operators move into the market, the range of
HD-voice-capable devices can be expected to grow.




However, one
particular issue island-type coverage must be addressed if HD voice is to
fulfill its potential. At present, if their operators support HD voice, users
can make HD-voice calls using a given network within a given country but
HD-voice services cannot be guaranteed when users roam or switch networks.
Operators who cannot guarantee call quality should take great care when
attempting to meet user expectations. This can be a challenge, as subscribers
are often excited by the potential of innovative technology and may have high
expectations. An inconsistent user experience such as when a single call
alternates between HD voice and standard quality as the user moves from one
radio access technology to another is likely to disappoint and strain
relations between the subscriber and operator.




is therefore critical. HD-voice services have been launched on both 2G and 3G
networks, and voice-over-LTE (VoLTE) will also support the technology. Fixed
subscribers can use HD voice through packet core over IMS, and a codec is now
ready to support the technology on CDMA networks. So HD voice can be a valuable
offering for all networks, and could play a key role in the evolution of GSM,
WCDMA, LTE, CDMA and fixed networks. It works best as an ecosystem where
subscribers can make high-quality voice calls from wherever they are to any
other location.


Interconnection is not an instant process, and island-type
coverage will persist for some time. To meet expectations it will be essential
to provide users with accurate information. The introduction of an HD voice
symbol for device displays, functioning in much the same way as the stereo
symbol on a radio display, would be one way to help users understand whether or
not they are on an HD-voice island. The recent introduction by GSMA of an
HD-voice logo [13] for use on, say, packaging for mobile devices will enable
consumers to identify HD-voice-capable products and solutions.




Parallel to
Ericsson’s vision of a Networked Society (in which anything that can benefit
from a connection will be connected resulting in more than 50 billion
connected devices by 2020) is an HD voice world in which anyone and anything
that can benefit from high-definition voice will do so.




HD voice can
ensure an improved user experience for a wide range of services and
applications. For example, voice-mail playback could be crystal-clear,
eliminating the need for a user to listen multiple times to understand a
message. The number of inaccurate translations in speech-to-text applications
would be reduced. Conference calls would be more effective, and reporters could
call a studio directly, knowing that their voices would be heard clearly,
making live broadcasting more reliable.


In short, improved voice quality makes a difference to people,
business and society. With HD voice, the world is more effective, personal and




The ongoing
data-traffic boom, driven by smartphones, tablets and next-generation fixed and
mobile networks, can coexist with a revitalized voice market. Voice is valued
as a personal way of communicating, and for operators, an attractive voice
offering will continue to be an important source of revenue and an essential
component of any successful business model.




The arrival of
OTT players offering free voice services while emphasizing quality has resulted
in greater urgency to improve voice services. Despite this, advances in voice
technology have been slow, making voice an exception in a telecom market that
has otherwise evolved at a remarkable pace.




The business
case for HD voice centers on four key areas: users make more and longer calls
when they have access to the technology; operator offerings can keep pace with
OTT services; enterprises can benefit from better voice quality; and the
technology supports mobility. For operators, the result in each case can be
improved subscriber loyalty and reduced churn.




Momentum is
building as HD-voice-capable networks and devices roll out across the globe.
However, delivering the best possible user experience and establishing HD voice
on a mass-market scale will require interconnection. HD voice has the potential
to be a valuable offering for all kinds of networks, and it will work best as
an ecosystem in which users are free to make high-quality voice calls to and
from anywhere in the world.




In the end, anything that can benefit from high-quality voice will
use high-quality voice, creating an HD voice world in which a wide range of
services and applications can offer a vastly improved user experience. Quality
counts: this is why HD voice will ensure communication services continue to
provide value to both operators and users.


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