Dear All.
If I need a PtP link that :
- Range : 50 - 75 km
- bandwidth : 10 mbps
- Spec : 802.11a
Question :
- Antenna : What is the antenna size I'll need ( in dbi ) ?
- How about useing amplifier such as stated at :
http://www.rflinx.com/Amplifiers/5GHz-A ... Series.htm
(They have 4900 Mhz - 5800 Mhz series)
It's 30 dbm non-OFDM and 24 dbm OFDM.
- RouterOS license. Is it :
++ Level-3 in both side ?
++ Level-3 in one side and level-5 in the other ?
Sincerely
-bino-
I think its technical. If you have poor signal and high noise and you power up it, your noise will also higher. Better yuse higher ants, that amps.I Could not find one selling this size of antenna.buy 2x solid parabolic dish 180cm diameter
Is it a technical or regulatory reason ?don't use AMP
Sincerely
-bino-
Yes its hard to find so large ants. Take a look at http://www.grante.hu.
Thankyou for your reply
Sincerely
-bino-
For this technical respon , I'll find one low Rx-GainI think its technical. If you have poor signal and high noise and you power up it, your noise will also higher. Better yuse higher ants, that amps.
Thanks, i'll check that siteYes its hard to find so large ants. Take a look at http://www.grante.hu.
Sincerely
-bino-
In my conutry i can buy these dish from http://www.mabo.pl they have good antennas :-)
It's very uncommon thing but is not impossible to find(You can import to Your country if you wery want)
I heard that some people made link's almost 60km long on 150cm dishes, without amp, with great 35Mbps speed's
Remember amp wil decerease speed (i think that 100mW atheros cards from mikrotik will do this job better) and have "only 250mW" on OFDM modulation
it's 3,5dBm more but rx-tx system will decerase speed so gain of using them is nonesens.
good luck
It's very uncommon thing but is not impossible to find(You can import to Your country if you wery want)
I heard that some people made link's almost 60km long on 150cm dishes, without amp, with great 35Mbps speed's
Remember amp wil decerease speed (i think that 100mW atheros cards from mikrotik will do this job better) and have "only 250mW" on OFDM modulation
it's 3,5dBm more but rx-tx system will decerase speed so gain of using them is nonesens.
good luck
You are making one little mistake... The Output power of each card is different, and is changeing when using different data rates... For example this is from CM9's tech. spec.:(i think that 100mW atheros cards from mikrotik will do this job better) and have "only 250mW" on OFDM modulation
it's 3,5dBm more but rx-tx system will decerase speed so gain of using them is nonesens.
Code: Select all
802.11a: 17 dBm @6Mbps, 13 dBm @54MbpsI'm not sure the above is right, but it seems so :)
Wow, would they be accepting competition from Bulgaria? :-)there was a contest (i think in the USA) for link-range a few months ago. the winning team did 85km at 11mbit/s, using 3m 50dBi dishes.
[we could even accept USA made antennas]
We get much better results with much better smaller antennas.
For example: (real world link), 83km, 1.2m at one side, 1.8m at other (link rate limited to 24mbps to avoid RTT fluctuations)
TX RX
9.06Mbps 1.13Mbps
That link routinely carries 11-12 Mbps (because the next in chain is limited to 10Mbps FDX radio)
On the topic: Indead cable lenght is major issue, as is cable quality. Amplifiers generaly do not improve wireless links - not only because of aplifying noise, but because amplifiers are not linear - while many do claim they are - truth is you can't get much quality at the price they are offered!
Another thing is, that it may not be legal to use high EIRP in most countries in these frequencies - I believe especially in Europe the 5GHz band is for lower power devices.
Daniel
83 km sound like a dream
My long link is 25 km and about 10 MB speed. 0.9 m antena with nstreme.
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