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What's better? Higher Radio Output or Antenna Gain? |
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Written by Start a WISP Site Admin
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Friday, 03 June 2005 |
"The question is the topic.
I am looking at a couple different
options for CPE's, and they both come in at the same EIRP +-1. They
just get there in different ways. I'm curious which is better.
First CPE
Radio - 80mW (19dBw)
Antenna - 19dBi
EIRP - 38dB
Second CPE
Radio - 250mW (24dBw)
Antenna - 15dBi
EIRP - 39dB
Both
CPE's appear to be using the Osbridge 24XL radio which according to
their website outputs 19dBw. I know the first does for sure. The second
does not say, but the web admin is identical. I can only assume then
that the latter radio must have a small amplifier integrated in order
to achieve the 250mW radio output. The price of the latter is about $40
more."
VariableARK:
higher gain antennas are going to better, less interference with them. i would go with whatever is cheapest.
superdog1:
Lets try this. Antenna gain is ALWAYS preferred over radio gain or
output power. An antenna is a passive device, where a radio must take
any given signal and amplify it to get it to the power level spec'ed on
the radio. Would You rather kiss a real woman(Assuming You are a man ) or a blow up doll?
DaDogs:
just remember that antenna gain adds to both end of the link.
16 dBm + 11 dBi = 27 dB EIRP
10 dBm + 17 dBi = 27 dB EIRP
The second system talks as loudly as the first but it HEARS twice as good (by range) and four times as good (by power).
That presumes the receive sensitivities are identical.
And
as SuperDawg mentioned, a narrower pattern on the CPE is less
sensitivite to interference ... but it is a bit harder to point.
mejiimbo:
It depends on what your situation is.
If you have 100% pure
line of sight, higher gain/less power, as others have advised. HOWEVER,
if you don't have good LOS, then a lower gain antenna with more power
seems to work a little better. It seems the lower gain antenna
"gathers" the reflected signals better, but it needs all the power and
receive sensitivity it can get in this situation.
Original thread location
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Equipment and Network Configuration