Hello,
I need to establish a link between two boats, then in totally free space, and guarantee connection within 8-10Km. Both antennas will be at same height from sea level, about 4m.
Should I use the Metal 2shpn with his standard 6db antenna?
Or it’s better to install antennas with more gain? Or put antennas higher level?
Thank you very much.
Omni antennas are not going to work at these distances.
First due to fresnel, antenna antenna should be at minimum 9 meters above sea level, that’s using 5GHz band, for 2.4GHz band minimum 14m height.
One possible setup would be providing one boat with 3x 120 degree sector antennas (4x 90degree sector antennas would be better), and the other boat with a directional one like mANT30, then align the mANT30 once they’re anchored.
Are boats moving constantly or connectivity will be established once they’re anchored?
thank you for this usefoul notes. The boat s are moving: a ship “mother” and a running drone sailing to collect data.
Any further detail to connect 3 sector antennas?
Thank you very much.
This is a quite difficult application. You’ve to study Antenna patterns and do some math.
As ships might tilt you might run out of the azimuth with antennas which have a small azimuth pattern.
So you first have to define maximal tilt (ships …), distance and height of the antennas. Then you have to calculate for the worst case with a given antenna. I would start with 2 omnis for calculation and if signal is too weak you see how much additional gain you need. Sectors tend to have a small azimuth range so you might need something with more azimuth.
If you have enough money I would look at the radwin solution they use for the moscow subway. They use beamforming to get a more flexible pattern.
With salted water you need a sealed solution. So stay away from open solutions like e.g. SXT. If you use multiple antennas test if the roaming works fast enough for your application.
Hi,
Over that sort of distance and between two moving targets, trying to get something to work at 2.4 or 5G is going to be tricky at best. Depending on your budget and how much data/bandwidth you need I would suggest doing it all at UHF (400Mhz). Downside is cost and the likely need for a radio license depending on where you are based.
Do a google on ‘Ethernet data radios uhf’ - hopefully something will appear that fits in with what you are trying to achieve.
Cheers
Jon
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