MikroTik

i want create a ptp link with SEXTANT G 5HPnD and 13km distance.
is it possible?
frequency interference = clean
LOS = very good
max bandwith=?

thanx alot

Yes its possible but not advisable

Why is this distance not advisable?

I have ordered 2 of these units and want to start deploying these
to add to / replace a ubnt network i have in place at this time.
Currently running WiMAX and need to push 200 to 300Mb to this location.

I have a link at 18.8km that I want to do and Towercoverage.com says I could.
Here is the outcome from the figures entered.

Site 1 (1)
Latitude 27.xxxxxxx °
Longitude -81.xxxxxx °
Ground elevation 70.1 m
Antenna height 12.0 m
Azimuth 309.56 °
Tilt -0.08 °
(2) Central Office
Latitude 28.xxxxxx °
Longitude -81.xxxxxx °
Ground elevation 52.0 m
Antenna height 33.0 m
Azimuth 129.49 °
Tilt -0.09 °
Radio system

TX power 30.00 dBm
TX line loss 0.50 dB
TX antenna gain 18.00 dBi
RX antenna gain 18.00 dBi
RX line loss 0.50 dB
RX sensitivity -90.00 dBm
Propagation

Free space loss 133.11 dB
Obstruction loss 0.00 dB
Forest loss 0.00 dB
Urban loss 1.00 dB
Statistical loss 15.95 dB
Total path loss 150.06 dB
Performance

Distance
18.899
km
Precision 10.0 m
Frequency 5745.000 MHz
Equivalent Isotropically Radiated Power 56.234 W
System gain 155.00 dB
Required reliability 90.000 %
Received Signal
-85.06
dBm
Fade Margin
4.94
dB

You can see from the calculations that the Recieved signal is too low. You should aim for maybe -60dBm to -70dBm with around 30dB SNR.
With -85dBm you will have low bitrate hence low throughput, not to mention I doubt it will be a stable link.
But on the other hand I have managed to achieve a -68dBm signal with an SXT on 1 side of a 16km link.

You can see from the calculations that the Recieved signal is too low. You should aim for maybe -60dBm to -70dBm with around 30dB SNR.
With -85dBm you will have low bitrate hence low throughput, not to mention I doubt it will be a stable link.
But on the other hand I have managed to achieve a -68dBm signal with an SXT on 1 side of a 16km link.

with reference to your last point what has been used on the opposite side of the SXT?

On the other side is an 433AH with unknown wireless card and a grid antenna. The SXT on my side replaced the same 433AH with similar grid antenna, because I had problems with the signal.

What you will do is impossible on 18 Km if you want a good point to point link use two the same antennas.

Take into account weather conditions.The signal will go down in bad weather.You lose your connection.You have to have a margin on your signal

So a SXT with 16dbi and Grid assuming 24dbi can complete a 16 km link. Is that right?

Yes, that is correct. SXT <-> 24dB grid - Tx/Rx : -63/-66dBm at ~15,2km

P.S. And this signal had no drops the entire winter - snow, low temps and possibly ice on antenna, heavy rains.

Hi Cybertod,

Can you do a print screen of your result to us. I find hard to belief.

Also, whats the total throughput you achieved ?

Regards

Here are some screenshots. The rate is 36mbit/s because on the other side of the link as I said is a 433 board with 5Ghz-A cabable wireless card.
The uptime is 17sec because I've changed from nstreme to nv2 so the distance is included in the screenshot. Otherwise completely stable with no disconnects.

That is awesome. whats the result with TCP. Both direction will be fine.

Regards

Abiola

20mbit/s Tx tested with tcp. Around 6mbit/s Rx.
I have more than 15 antennas on the tower and the low Rx is due to self noise mostly.

thank you for the info.