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bino
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50 - 75 km , 10 mbps , PtP

Sat Dec 04, 2004 12:27 pm

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-
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marksx
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Sat Dec 04, 2004 10:17 pm

buy 2x solid parabolic dish 180cm diameter
don't use AMP
use VERY SHORT CABLES
 
bino
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Sun Dec 05, 2004 5:46 am

buy 2x solid parabolic dish 180cm diameter
I Could not find one selling this size of antenna.
don't use AMP
Is it a technical or regulatory reason ?

Sincerely
-bino-
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mip
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Sun Dec 05, 2004 11:04 pm

buy 2x solid parabolic dish 180cm diameter
I Could not find one selling this size of antenna.
don't use AMP
Is it a technical or regulatory reason ?

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.
Yes its hard to find so large ants. Take a look at http://www.grante.hu.
https://www.youtube.com/watch?v=j7q0Y_JZMrg - the country you must visit
 
bino
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Mon Dec 06, 2004 3:15 am

Thankyou for your reply
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.
For this technical respon , I'll find one low Rx-Gain
Yes its hard to find so large ants. Take a look at http://www.grante.hu.
Thanks, i'll check that site

Sincerely
-bino-
CERTIFIED CI$CO HATER
 
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normis
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Mon Dec 06, 2004 9:19 am

- RouterOS license. Is it :
++ Level-3 in both side ?
++ Level-3 in one side and level-5 in the other ?
Level 4 at both sides. Level 3 doesn't have wireless.
No answer to your question? How to write posts
 
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marksx
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Mon Dec 06, 2004 9:18 pm

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
 
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mag
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Mon Dec 06, 2004 10:32 pm

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.
 
mip
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Tue Dec 07, 2004 12:30 am

We have two long-range links:

- one for about 30km, 12mbps tested, two dlink ab520 (511) and 90cm dish
- other for about 37km, 15mbps tested, two mt card (5212 I think) and 80 cm dish.

Both stable, we use 2 and 5 mpps full d. on them.

But fog is not our fiend...
https://www.youtube.com/watch?v=j7q0Y_JZMrg - the country you must visit
 
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[ASM]
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Tue Dec 07, 2004 1:11 am

(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.
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.:
802.11a: 17 dBm @6Mbps, 13 dBm @54Mbps
OK.. but what is the tx-power at 5ghz-turbo mode? I think that the tx power must be divided by 2, because of doubled frequency range that is used... so we have that the tx-power at 36 MBps in 5ghz turbo mode is something like 8 dBm... the difference between 25 dBm and 8 dBm is 17dBm

I'm not sure the above is right, but it seems so :)
 
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marksx
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Tue Dec 07, 2004 12:45 pm

Yes, but Amp won't work at speeds 54Mbps on this power too.
 
Baltos
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Fri Dec 24, 2004 10:12 am

[quote]buy 2x solid parabolic dish 180cm diameter
don't use AMP
use VERY SHORT CABLES[/quote]


HOW SHORT IS THE CABLE (the LMR cable) ???
SHOULD I USE LMR-600 CABLE TYPE ???

Thank you and regards
 
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marksx
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Fri Dec 24, 2004 12:32 pm

i think that you can connect card with feed only 1-2meters cable in this case it will be enough if you use CNT/LMR-400, if you need longer cabling (cable-feed) you need to use lmr-600 but maximum reasonable length is not more than 5-6meters in this case
 
daniel
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Fri Jan 14, 2005 8:32 am

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.
Wow, would they be accepting competition from Bulgaria? :-)
[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
 
ice
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Fri Jan 14, 2005 8:50 am

hi, do you use OFFSET 1.8m or Primary Focus 1.8m?
 
amsco
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Thu Feb 03, 2005 9:23 pm

Daniel can you give more details on your 83KM link, hardware, software, config etc.

thanks
 
sgb
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83 km sound like a dream

Sat Feb 05, 2005 2:23 am

My long link is 25 km and about 10 MB speed. 0.9 m antena with nstreme.

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