MikroTik

Posted: **Wed Sep 28, 2005 1:23 am**

Hi, I need to make a link at 129 km. of distance, the first point is located at a plain terrain, and the other point is located on a mountain at 1600 Mts, then... i have a free fresnel area!.

I gonna maka a experiment with two 31 dbi anthennas, 2 pc with Microtick Os 2.9, 2 Senao PCI cards chipset Atheros, and two amps 1W. Configurated in nstrem mode and turbo mode

i need transmit 5 Mbps.

can i make it's works?

any recomendations?

tks... sorry my english es very bad!

Posted: **Wed Sep 28, 2005 4:52 am**

I dont know what kind of amps you will be using, but I dont think they are gonna work with turbo mode...Also I am a little sceptical about nstream with amps but I gues it should work...
Well...good luck :)

Posted: **Wed Sep 28, 2005 8:43 am**

rule number one - don't use amps. ever

Posted: **Wed Sep 28, 2005 10:58 am**

Unless you play loud music of course

Posted: **Wed Sep 28, 2005 10:59 am**

Posted: **Wed Sep 28, 2005 6:11 pm**

IGadget, we to make a 109 Km link to 3 Mbps (TCP) with the following configuration.

Point 1:
3490 m altitude.
24 dBi grid Antennas.
2.4 Ghz Celeron CPU.
20 m LMR 600 cable.
Atheros R52 card.
Don`t Nstreme.
2.9.2 Mikrotik version.

Point 2:
2700 m altitude.
24 dBi grid Antennas.
2.4 Ghz Celeron CPU.
20 m LMR 600 cable.
Atheros R52 card.
Don`t Nstreme.
2.9.2 Mikrotik version.

With 31 dBi anntenas 139 km are possible mountain to mountain. I don´t have experience with mountain to plain land.

This is my recomendation:

1. The 31 dBi antenna is very difficult the align. First align with 24 dBi and later replace. To align antennas, to take into account the altitude difference (to align vertically also)
2. Use Lighting arrestor, ethernet and 120 VAC protector in both point. Is important, for probe and align antennas don´t have the lighting arrestor install.
3. If use RB230 or 500 outdoor, use POE protection en both ends. This is very sensitive to electric storm.
4. Use short coax antenna cable en both ends.
5. Don´t use amplifiers (Normis recomentation).
6. Patience.

Posted: **Sat Oct 01, 2005 4:09 pm**

rule number one - don't use amps. ever

May I ask why that is a bad idea? 129 km is a very long distance for a wireless link.

Posted: **Sat Oct 01, 2005 9:25 pm**

With amps all you end up with is extra noise.
For a variety of complex .. quantum .. reasons, the S/N ratio goes down and you are worse off.

THE best noise free amplifiers are HIGH GAIN antennas .... and of course, these also have the advantage of amplifying both RX and TX signals equally. IE a 20 dBi gain antenna has this gain for RX and TX.
With an amp you just don't know..

If I could be bothered to look up text books I might explain intermodulaton and noise and intercept points etc but basically - amps are a baaadddd idea..

Posted: **Sun Oct 02, 2005 3:32 am**

What brand of lightning protectors are you using on 5Ghz. Any recomendations.
Thanks :)

Posted: **Sun Oct 02, 2005 3:52 am**

With amps all you end up with is extra noise.
For a variety of complex .. quantum .. reasons, the S/N ratio goes down and you are worse off.

I think that amplifiers is a lot better nowadays, atleast what I've read. Here is a quote from one vendor.

All SSB Electronic Wireless LAN RF amplifiers contain ultra low noise preamplifiers with the lowest noise figures in the industry - as well as integrated bandpass filters which results in an increase in the strength and readability of the incoming data transmission. Coupled with an ultra linear RF amplifier, this bilaterial improvement of both the received and transmitted signals results in unequalled wireless network performance.

SSB Electronic's WL-2400 50 wireless LAN RF amplifier with integrated Ultra Low Noise receive preamplifier has been designed to interface with the Lucent Technologies IEEE 802.11 wireless LAN cards including their new Turbo wireless cards. In addition, the WL-2400 50 supports the Lucent Technologies implementation of receive diversity. Versions of the WL-2400 50 can be produced to interface with other data transceiver cards.

The WL-2400 50 contains an Ultra Low Noise receive preamplifier with an internal NF of less than 0.5dB. This amplifier can be configured with optional 3, 4 or 5 pole bandpass filters for operation in extremely hostile RF environments.

Posted: **Sun Oct 02, 2005 4:22 am**

Gain with antennas is much higher than with amps, so no problem to that link is my opinion. Hard to say about the speed.

Im working on a record in our country with 146km link, 42dbi 180 dishes, i calculated full speed, how much i will get i will tell later

Posted: **Sun Oct 02, 2005 11:21 am**

Nevertheless... amps both increase noise and reduce dynamic range..
And usually do not amplify both TX and RX signal.

Antennas do not increase noise but give gain to both TX and RX signal.

Your quote from literature - ok, it would say they are good as it is trying to sell you an (expensive??) unit !
I accept they are **better** than they were, but they are still not the best solution - except in very few cases..

However - I wish you good luck which ever solution you choose!

Posted: **Wed Oct 05, 2005 1:27 am**

Hi, tks for answer!

We make an experience with 2 senao AP (200mw) (without mikrotik)
using a ministubler and trafmeter, we obtein this:

signal:
rx: -76 dbi
tc: 30 dbi
noise: -95 noise

max transference rate: 300 kbps

then i think we have a good relation of signal/noise, and the amps can cover the loss of the cable, conector, etc..
and the problem is the software (ack timout, etc...) and this may be resolve with mikrotik

Tks All!

P/D1: artist1 good luck, with the 146!
P/D2: Alguien habla español (el ingles me esta volviendo loco!) jejeje

Posted: **Wed Oct 05, 2005 1:51 am**

Hello IGadget. I speak spanish, but the official language of this forum is the English.

You can write me in spanish to msolis@reicocr.com

Posted: **Wed Oct 05, 2005 3:23 am**

Tks... mail sent.

Posted: **Wed Oct 05, 2005 2:23 pm**

Where are you from? It has worked for you?

admin note: english only please

Posted: **Wed Oct 05, 2005 4:44 pm**

Im from Argentina, it was only a test and it worked, but i could only transfer 300k, now i´m gonna try with MT.

where are you from?

Posted: **Thu Oct 06, 2005 3:51 pm**

IGadget: use larger (in size) parabolic antennas possible... You'l get more dBi and lower beam-width (of signal)...

If you have an 1 degree antenna at distance of 130 km you'll get an field wight of 2.26 km.

With 24 dBi antena with 8 degree beam-width your field wight will be 18 km!!!

Posted: **Wed Oct 12, 2005 2:47 am**

Hi, tks for answer!

We make an experience with 2 senao AP (200mw) (without mikrotik)
using a ministubler and trafmeter, we obtein this:

signal:
rx: -76 dbi
tc: 30 dbi
noise: -95 noise

max transference rate: 300 kbps

then i think we have a good relation of signal/noise, and the amps can cover the loss of the cable, conector, etc..
and the problem is the software (ack timout, etc...) and this may be resolve with mikrotik

Tks All!

P/D1: artist1 good luck, with the 146!
P/D2: Alguien habla español (el ingles me esta volviendo loco!) jejeje

your speed is because of stupid senao that does not have dynamic Ack value and thats why you get low bandwidth. try MT and i'm sure you can get 6mb at least (with that quality)

Posted: **Thu Oct 13, 2005 1:14 am**

Hello friends of the forum, finally we made the connection of test, and I work, with a very good transference and a good stability

, this is the report:

Distance: 129 Km
Fresnel area: clean without obstructions
PC Router : 2 Celeron with Mikrotik - Nstreme 1 (demo licence)
Radios: Senao PCI atheros 100mw
Ack-Timeout: 850 us
A/G Mode
Freq:2.4
Signal: -76 Noise: -94
Meteorologic conditions:optimal
Amps: No

Bandwidth Test Result Average: 7.0 Mbps tx 7.0 Mbps rx
Fading: 9%

thanks to everybody for the collaboration, now we will put the connection operative.

Posted: **Thu Oct 13, 2005 2:58 am**

Very nice.
What cards do you have 100mw or 200mw?
Are they miniPCI senao? Which model?
And what cable do you use and how long?

I'm too from Argentina

You're from Mendoza?

Write me at tkmbe@yahoo.com

Greetings

Beat

Posted: **Thu Oct 13, 2005 11:17 am**

Well done mate

Very good news!

Good luck with the link...

Posted: **Thu Oct 13, 2005 11:53 am**

what kind of antenna are you using?

Posted: **Thu Oct 13, 2005 11:22 pm**

what kind of antenna are you using?

Parabolic complete 31dbi

Posted: **Fri Oct 21, 2005 12:44 am**

where did you get a 31db 2.4ghz antenna?

Posted: **Mon Oct 24, 2005 6:55 pm**

where did you get a 31db 2.4ghz antenna?

http://www.eiffelweb.com.ar/wireless.htm

Posted: **Sat Nov 12, 2005 12:03 am**

so if amps are a bad idea. do i have a problem with my config

Routerboard 220 running MT 2.9.6
800mW amp
15db omni antenna
Atheros ARP5213 wireless card

and

Routerboard 220 running MT 2.9.6
800mW amp
12db NLOS omni antenna
Atheros ARP5213 wireless card

Please could someone estimate the range of this equipment for me and how it would work without the amp and which of the 4 options would work best in a radius of 5km.
terrain is that of a small town
i mean should i pull out the amp

MikroTik

129 Km Link

129 Km Link

Tks -ALL for answer

Re: Tks -ALL for answer

Works!