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Old July 4th 06, 08:42 AM posted to rec.radio.amateur.homebrew
Reg Edwards Reg Edwards is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 167
Default How to calculate increase of home wireless router range?


"Beverly Erlebacher" wrote in message
.. .
Can you help me roughly CALCULATE how to increase the range of my

home
Internet wireless WiFi setup to a shed 300 feet away from my house?

Presently, I can walk about half the way through the wooded area to

the
shed with my laptop in hand before I lose the connection to the

PCMCIA
802.11b,g Linksys card. Basically I need to gain 150 feet in

"range".

But how?

At the store, I immediately become confused as I try to compare $30

USD
omnidirectional antennas (D-Link ANT24-070) that boost "power" by a

claimed
7 db; $50 USD directional corner antennas (Hawking HAI15SC) that

claim 15
dbi (whatever a dBi is); and $150 USD 802.11N routers that claim to

boost
omnidirectional "range" by 4x (Linksys WRT300N).

How does an omnidirectional 7 db or directional 15 dBi boost in

"power"
equate to range?

Approximately how many decibels of (omnidirectional or directional)

power
do I really need to boost my WiFi range from about 150 feet to the

300 feet
I need?

Looking up what a decibel is
(http://en.wikipedia.org/wiki/Decibel#Definition), I
calculate the D-Link ANT24-070 omnidirectional antenna gives me

about 5
times the power (assuming 7 db = 10^7/10 ~= 5); but does this get me

the
additional 150 feet of range to my shed?

Spending almost twice as much money on the Hawking HAI15SC

directional
antenna gets me roughly 30 times the power (assuming 15 db =

10^15/10 ~=
32); but is that enough power to get me the range to my shed?

Indeed, is there some way to add a Hawking 15db antenna on the

receiving
end to get 1,000 times the power (15 db + 15 db = 30 db = 10^30/10

~=
1,000); but what would I hook the wire output from this receiving

antenna
to in the shed (I can't hook it to the pcmcia card, can I)?

Given those db calculations, how do I compare the antenna options

with
replacing my home 802.11b,g router with the 4X range $150 USD

Linksys
802.11n WRT300N router and the required $120 USD Linksys WPC300N

PCMCIA
card (assuming 6 db = 10^6/10)?Will this three-antenna 802.11n

router be
forced to drop down to 1X speeds because inside my house my kid's

laptops
will all be using 802.11b or 802.11g? Or can the router work on both
802.11g to one computer and on 802.11n to the other computer at the

same
time?

I'm so confused!

All I want is to make a well-informed buying decision to increase my

WiFi
range reliably to 300 feet to a known point.

Can you help me sort out all these very confusing variable (to me

anyway)?
I have no training in electrical engineering; but I can google.

Thank you,
Beverly

==========================================

Very simply - four times the transmitter power ( +6 dB ) doubles the
range.

Is your receiver sufficiently sensitive? Or is the received signal
below the noise level?
----
Reg.