an antenna that fits your plan. An
omnidirectional unit is best if you
have lots of space to cover in all directions. But, if all of your wireless clients
are off in one direction, you may want
to consider a directional antenna that
focuses power where you need it.
Such directional antennas exhibit
gain and give the same effect as
increasing transmitter power. Some
typical directional antennas are the
ever popular Yagi, as well as vertical
collinears and the flat patch
Most home access points have
dual antennas for receive diversity
that helps improve performance. The
antennas are spaced from one another by at least one wavelength and the
receiver switches between them to
see which gives the best signal. Refer
to Figure 2 again. After market antennas are also widely available so if you
need to fix a problem or improve reliability, experiment with the antennas.
WLANs: What's in it
Actually, there is something for
everyone. If you are thinking of
extending your company's Ethernet
LAN, give some serious thought to
802.11. It offers many benefits. It
improves work productivity because
of the mobility it provides. You can do
company work from anywhere. It also
simplifies installation. No need to pull
cables. This reduces labor and materials cost. Free space is ... duh ... free.
Users can move offices or do work
wherever. And the network also
scales better as the number of users
As an individual, you may want
or need the ability to work while traveling. Road warriors — those people
who travel frequently for their companies — are real big fans of WLANs
because they can stay in touch by
laptop and hot spots with Email and
have Internet access virtually anywhere. Even some new PDAs are getting Wi-Fi capability thanks to the
lower power chipsets. If you don't
have Wi-Fi service now, you will find
that your productivity will increase
tremendously on the road if you do.
For consumers, a WLAN is also a
viable option. The cost of setting up a
home network with Wi-Fi is less than
$200.00 today and getting lower. You
can get a wireless access gateway or
router for under $100.00 if you shop
around. Add a few bucks more for the
adapter card and you are on your
way. No need to do any wiring. If you
have a laptop, be prepared to rapidly
get addicted to the freedom that wireless provides.
P.S. I've been writing this column
for over a year now. I have lots of great
ideas for future installments, but I
would like to hear what you want to
read about. Do you want more tutorial articles, like how spread spectrum
or OFDM work, or would you like to
see more hands-on construction/
applications articles on wireless?
What about ham radio or SWL? Drop
me a line via Email (lfrenzel@sbc
global.net) and give me your wish
Institute of Electrical and
This is the Ethernet standards
website with more than you ever
wanted to know about it.
The trade association that certi-fies 802.11 WLAN equipment.
A general website with tons of
data on WLANs and lots of other
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