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TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine
— 01-02/2013
—
outdoor use. So we were left
with no other choice than to
find out ourselves.
Using a small LCD TV we
moved out into the garden
of our editorial offices and
mounted the transmitting
module on a window facing
the garden. The distance be-
tween the two modules was
27 meters without any ob-
struction, and the Wireless
HDMI Extender achieved its
mission brilliantly. We were
able to watch flawless HDTV
without any noticeable inter-
ference. It was only when
we increased the distance
to more than 40 meters that
the LED indicating a success-
ful connection between the
modules stayed dark.
Thus we can confirm that
the Antiference Wireless
HDMI Extender performs
as specified when used out-
doors and with optimum po-
sitioning of the transmitting
module.
What about indoor use?
To start with, it all depends
on the type of walls within
a building, since a thin dry-
wall obviously will let through
considerably more signals
than a massive wall made of
reinforced concrete. The re-
sults will invariably differ, but
this is not to blame on the
The 5 GHz band was only
released for public use in
2009 and offers a total of 19
separated channels without
overlap (as opposed to mere-
ly three 2.4 GHz channels),
which can be used by devices
such as the Antiference Wire-
less HDMI Extender. In addi-
tion, the higher frequency in
combination with improved
error correction routines al-
lows for data rates of up to
600 Mbit/s, which also com-
pare extremely favourably
to the 54 Mbit/s that can be
achieved using the 802.11a
standard in the 2.4 GHz
range.
The Wireless HDMI Extend-
er itself can deal with resolu-
tions all the way up to 1080p
60 Hz Full HD (which means
a maximum of 1920x1080
individual pixels) and sup-
ports HDMI 1.3 as well as
the HDCP 1.2 protocol for
copyright protection. Thanks
to also supporting the EDID
(Extended Display Identifica-
tion Data) protocol it is possi-
ble for TV panel and receiver
to wirelessly arrange for the
best possible display resolu-
tion and to make sure users
can enjoy optimum video
quality with the hardware at
hand.
The MiMo (multi input/mul-
ti output) method is used for
signal transmission, which
means multiple antennas are
built into both the transmit-
ting and receiving modules
using a total of four different
channels. In addition OFDM
(Orthogonal Frequency Divi-
sion Multiplexing) allows for
optimum error correction
and limits the risk of outside
interference with the signal.
Now that we had run
through all the techni-
cal specifications, we could
hardly wait to see the sys-
tem at work. To that end, we
connected a HDTV satellite
receiver to the transmitting
module and a 42-inch LED TV
to the receiving module.
For our test purposes, both
devices were positioned in
the same room so we expect-
ed a successful transmission
at any rate. And so it was: A
few moments after we had
powered up both modules of
the Wireless HDMI extender
all LEDs lit up in green to in-
dicate that (a) a connection
had been established be-
tween the transmitting and
the receiving end and (b) a
HDTV device was connected
to each module. All that was
left to do for as was to turn
on the TV to witness first-
hand how the receiver in one
corner of the room provided
a crystal clear 1080p signal
to the TV panel in the oppo-
site corner of the room com-
pletely without a cable.
Since we’re talking about
strictly digital transmission
there is no video noise or
similar interference and the
wireless signal we received
was 100% identical to a sig-
nal we would have received
with a direct cabled connec-
tion between receiver and
TV.
Commands sent via in-
frared from the remote also
reached our receiver flaw-
lessly so that in terms of user
experience there was no dif-
ference whatsoever between
our set-up and a convention-
al installation using cables.
Wireless
transmissions
from one corner of a room
to another are nice and con-
venient, but hardly a techno-
logical breakthrough, so we
wanted to find out next how
much the distance between
transmitting and receiving
modules could be increased
without compromising signal
quality.
In the technical specifica-
tions the manufacturer states
a maximum of 30 meters, yet
does not specify whether this
distance refers to indoor or
