HD Voice: A Real Alternative
The author is U.K. sales and
marketing manager for Glensound.
Regarding Radio World’s feature “Let’s Talk About Codec Trends” (Jan. 2), I
think it is important to state the role that HD Voice is playing in the
broadcast world on the mobile phone networks (as opposed to fixed line codecs),
as compliment to the options stated in your feature.
HD Voice devices are not an alternative to
stereo full-bandwidth codecs in just the same way that stereo full-bandwidth
codecs are not the solution in all applications. If the requirement is
single-channel voice reporting for news and sports, HD Voice on 3G networks
offers significant benefits, for several reasons.
In countries that offer HD Voice on their 3G
mobile networks, the ability to get signals on air is greatly increased. In
congested environments (stadiums, sport events, concerts, film premiers, etc.)
there is a high demand on the IP network.
In these environments, HD Voice offers a reliable and simple connection
option, just using a battery powered, portable mobile phone. In the U.K.,
the BBC used our own HD Voice version for audio broadcasts following the
Olympic torch relay, as there was low availability of IP bandwidth due to
people taking pictures and posting them to Facebook (for example).
Within the mobile telephone world, it is
important to realize that HD Voice is just a voice call on the mobile network,
so it does not need to use the mobile data service — a normal voice SIM is all
that is required. This means that it is separated from all data issues of
bandwidth availability and fluctuation.
Once the call is connected, it will stay connected in the same way as a
mobile phone. The only exception to this is if you are travelling and move
out of the network area, but most broadcasters will be stationary for reports.
A phone call is always much easier to establish and maintain than an IP
If the requirement is single-channel voice, then
HD Voice will give you a 7 kHz link. It’s not stereo, and it isn’t
suitable for music; but for voice broadcasting, it’s all that is needed.
It is also very effective at suppressing background noise so that news
reporters can be heard clearly.
3. Ease of Use
It’s a phone. Calls are as simple to establish as a normal mobile,
and no setup or configuration is required. Non-technical reporters or
announcers love this fact.
HD Voice is G722.2 or AMR-wideband. There
is no need to pay the prices for codecs that give multichannel, or the high-quality,
high-bandwidth algorithms, if all you are going to use it for is single-channel
The delay is the same as a normal mobile phone
call, so it is perfect for two-way conversations. You do not need to allow
buffering on a HD Voice system. Indeed, on tests in the U.K. on the Orange
network, on the same cell, the HD Voice delay was actually less than a normal
mobile phone call.
HD Voice is still fairly new and it is not
available everywhere (it’s not yet in the U.S. for example, but it’ll be there
soon). So far, HD Voice is available in about 39 countries and this is
increasing all the time.
At the moment, the call has to be on the same network, within the same
country (with one recent exception). For most broadcasters, this is not a
problem. All current systems are on the 3G network, but versions for the
4G network are expected to follow.
The example given in the codecs article, about Italy, was
interesting. At Glensound, we supplied 40 HD Voice 7 kHz Broadcasters’ Mobile
Phones recently to Rai. Giovanni Ridolfi, head of RAI Radio Engineering,
commented on the high audio quality, low latency and robust connectivity and
said that RAI’s journalists found the unit intuitive to use.
a broadcaster has access to HD Voice on mobile networks, it is a real cost-effective
alternative for remote broadcasting.
Glensound provides solutions for
remote news and sport reporting. Marc Wilson has been working in audio for 23
years. Comment on this or any story; email firstname.lastname@example.org.