Datum 2014
and furniture. And those signals are 10,000 to 100,000 times
more powerful than the reflections off a human body.
Katabi'swi¬vi sends out two wireless signals, one of
which is the inverse of the other. In what Katabi calls "interference nulling," the two signals cancel each other out
unless they hit a moving target – such as a human.
"To silence the noise, we change the structure of
the Wi-Fi signal so all the undesired reflections cancel," she
said.
Make a parabolic Wi-Fi extender in minutes and
double your wireless
The device is meant to be portable so, for example,
a person worried that someone was hiding in the bushes
could do a quick scan for her personal safety.
Metal objects and water also will block the signal. Position
Wi¬Vi could also serve as a high tech baby monitor or help
routers at least two feet from things like metal filing cabi-
Superman – or just cops – catch baddies.
nets, appliances and fish tanks.
Change the channel:
Wi¬Vi could also serve as a high tech baby monitor
or help Superman – or just cops – catch baddies.
6 Ways to Get a
Stronger Wi-Fi Signal
at Home
Interference from other household electronics and
your neighbor's Wi-Fi network can reduce your router's signal. Wi-Fi routers transmit signals on one of three channels:
1, 6 and 11 in the U.S. The default for most routers is set to
6 by the factory, but you can change it to a less-trafficked
channel.
Find your router's configuration page address on
One or two bars on your laptop's Wi-Fi signal
the manufacturer's website. Open settings and choose a
strength indicator is just one of the signs that you've got a
new channel. Wait a few minutes to determine if your signal
weak signal. Movies take forever to load. Webpage loading
has improved.
stalls. Or maybe you've seen the dreaded message: You are
no longer connected to the Internet.
Trial and error is the only way to find out which
channel is least congested. The best channel will vary from
You may be able to improve your Wi-Fi signal at home by
house to house, depending on which channels other wire-
making a few simple changes.
less devices in your area are using.
Reposition the router:
Replace the antenna:
Is your wireless router in the basement or tucked
Moving the router to a central position may not be
unobtrusively into a corner? You may be losing as much
feasible because the router must be connected to your ca-
as half the signal. Most routers are omnidirectional, send-
ble box or other Internet modem. If this is the case, you may
ing signals is a circular pattern like the ripples from a rock
be able to upgrade the router's antenna to a so-called high
dropped in the center of a pond.
gain antenna, which could double your router's signal.
For best performance, position your wireless router
Check to see if your router's antenna is removable.
in a central location away from exterior walls and off the
Alternately, your router may have a jack available for an ad-
floor. If you live in a multistory house, place the router on the
ditional antenna. Verify that the new antenna will fit your
main or middle floor.
router. Replacement antennas begin at around $20.
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