Hello guys!

I would like to start a discussion about link I'm currently working on.
Every advice is welcome!



Almost entire link is over the sea.
Height
LocationB: 175 meters above the sea level
LocationA: 20 meters above the sea level
Total Distance: 25,74 kilometers per google maps
Device on both sides: LHG 5 with v6.40.1

Signal:


Settings:


10 minutes bandwidth test (TX from AP):



I will provide with more details (Radiomobile, and so...)


This is what I'm currently working on.
Thing that is making me worried is I have a lot of signal fluctuations, sometimes it goes to -80, most of the time is around -74, and the best is around -67.
I believe this is because of the sea, and humidity.

Would be really nice to hear some other opinions!

Yes, this is typical for over Water links, if this is LHG5 with 25 dbi, Use bigger Antennas, if your Budged is Low, use Mikrotik LDF 5 and cheap 100cm Sat Dish

You are right its the one with 25dbi. Well this is first time I've seen this device from Mikrotik LDF which can be combined with satellite dish.

I was thinking when I get in hold of it... to test with DynaDish on one side.

Currently I have one more link over the sea with on one side QRT and one 911 and LHG connected to it.
Works really nice!
Currently I'm setting up The Dude to monitor signal over graph so I can compare results, but having the link "stop" every 4-5 hours for several seconds... it's not that bad for P2P LHG5

Actually these are not bad results at all!

No thats not bad for this distance over sea!
There are 2 thinks that helped with signal Fluktuation over Water

1. more antenna gain
2. higher Antenna Position

If you dont have small Budget buy 34dbi Dishes and 2 netmetal

It is very typical to see those variations due to strong reflection from the water surface and varying "cancellation"
due to the tides that make the reflected path length vary (while the direct path remains the same).

In theory it should be better when using circular polarisation, but it will be a lot of effort to confirm that.
(using separate circular polarised feed on a suitable dish, and electronics-only device like netmetal)
Of course then you have only a single chain, so potentially lower throughput.

Wait for https://mikrotik.com/product/RBLHG-5HPnD-XL
Even if you change at only one end, it will be a visible improvment.

Calculator estimated link with 2 x RBLHG-5HPnD-XL:
Distance: 25.1 Km (15.59 miles)
Free Space Path Loss: 135.132 dB
Theoretical signal level at TX: -59
Theoretical signal level at RX: -59
Link status: Reliable

Calculator estimated link with 2 x RBLHG-5:
Distance: 25.1 Km (15.59 miles)
Free Space Path Loss: 135.132 dB
Theoretical signal level at TX: -70
Theoretical signal level at RX: -70
Link status: Unreliable

No thats not bad for this distance over sea!
There are 2 thinks that helped with signal Fluktuation over Water

1. more antenna gain
2. higher Antenna Position

If you dont have small Budget buy 34dbi Dishes and 2 netmetal

Unfortunately on the other side it's not possible to get higher position then this 20-30 meters above the sea level.
I would have to change my location completely (which I'm planning just to get some approvals from goverement)
Thanks for suggestion, I'll keep that in mind for my next test, actually never tried to make wireless links using dishes...

It is very typical to see those variations due to strong reflection from the water surface and varying "cancellation"
due to the tides that make the reflected path length vary (while the direct path remains the same).

In theory it should be better when using circular polarisation, but it will be a lot of effort to confirm that.
(using separate circular polarised feed on a suitable dish, and electronics-only device like netmetal)
Of course then you have only a single chain, so potentially lower throughput.

I still have pretty decent results using this two "affordable" devices. Currently I'm getting different devices for testing, so I'll come up with different test later on.

Wait for https://mikrotik.com/product/RBLHG-5HPnD-XL
Even if you change at only one end, it will be a visible improvment.

Calculator estimated link with 2 x RBLHG-5HPnD-XL:
Distance: 25.1 Km (15.59 miles)
Free Space Path Loss: 135.132 dB
Theoretical signal level at TX: -59
Theoretical signal level at RX: -59
Link status: Reliable

Calculator estimated link with 2 x RBLHG-5:
Distance: 25.1 Km (15.59 miles)
Free Space Path Loss: 135.132 dB
Theoretical signal level at TX: -70
Theoretical signal level at RX: -70
Link status: Unreliable

I used the Mikrotik calculator, and also I had unreliable, but... had some spare time, and testing equipment... why not give it a try, and still decent results!
My company should recieve some of those new LHG's so I'm definately placing at least one for beginning, will let you know about the results!
New LHG should go to location B, which is unfortunately really really low in height.





Thanks guys!

What were the results?

use netmetal in combination with mant30 in slant polarization and you a ok

hm, a da probaš frequency mode?

hm, you can try change frequency mode?

superchanel work great

Hello.
I am in a similar situation where I have "eye" contact and an unstable connection between an access point (Ubiquity Bullet M2) that I do not own and my receiver which is a Ubiquity AirGrid M2 HP with the small 16db antenna. The access point is at 30m above sea and I am receiving at 40m above sea. Between two points is just sea and nothing more and the real distance is 22.9Km. Even if this connection is unstable, I find it almost unbelievable to have a connection at such great distance with such a small gain antenna.
However I would like to have a better connection, a stable one, I do not have high expectations on speed, I just want to do my everyday job at my pc (and the reason that I do not have a paid connection is that the carrier do not give me telephone and internet connection because -they say- I am too far from the closest hub...).

Anyway. I have an 80cm brand new 38db satellite dish and I also am considering to buy a Mikrotik LDF2 . Do you think I will have a better and more stable connection with the same access point I am linked presently?

Do you happen to know what Mikrotik product could be considered as safely comparable (<=)with Ubiquity Bullet M2 in order to make the simulation of connection at Mikrotik's website?
Thanks in advance for your help.

Bellow is a screenshot of my current situation with my unstable connection

You must consider that most likely provider has activated Airmax which is compatible only with ubnt products.
If is a hotspot, it should be disabled.
Otherwise LDF2 will be better than AG2.
You will get an ~10dbi improvement.

Thank you @Inox for your reply. I will proceed to actual testing of LDF2 since I bought it today. Now.. I am a total newbie at router-os and if I say that I know a bit about networking that will be at least an exageration! I find router-os quite complicated for me but I understand that this would be a swiss knife for someone who knows about wifi networking. I had to use my windows pc and winbox.exe in order to create a link with the target access point, which by the way is not locked/compatible only to ubnt products. I have to calibrate the dish which is a bit difficult since I do not know what is the proper angle in order to target a bit lower than horizontally. What do you think? Is it possible to make connection with the dish turned upside down like I have it at the photograph? If yes and in that case should I turn LDF2 upside down also along with the dish? ( I know that I will have to take care in order to insulate the LDF in order not to take water in case of heavy rain )
I hope I will have the time to set it tomorrow. I will update on this matter.

The verdict is not bad but not good also.
I can establish connection with my target but it's highly unstable. It is, more or less, practically the same with the small 16db airgrid at 25Km. Maybe there is a lot of interference and it is highly improbable to achieve a good connection with this particular access point no matter what wifi station I am going to use or what antenna..But the router-OS is so much complicated.. you get lost on submenus after submenus. After initially connecting to 192.168.88.1 this address change in some magic way and then you can't connect to router OS from your web browser.. only with winbox. And winbox does not work correctly with WINE and linux mint, so I had to log out and use windows.. Maybe I am simply not used on this software but even using the simple tool of antenna alignment was not possible. As a solution, after half an hour of trying youtube suggestions in vain and in order to finish with this task while still having daylight, I had to get my laptop beside the antenna and a long power cable extension in order to power Mikrotik's POE and align dish manually by looking where the antenna gets it's higher signal from access point.
On the other hand; I tested LDF2 with a nearby (750m) access point -without using dish- and it was exceptional. Very good signal and good speed as well. But for very the long distance connection there is a problem. And router-OS is problematic.

Complication is due to so many options you can set. It's on you if you use full user interface or quickset or another brand product. Finally you can find all the customizable options useful when you understand them.

Hello there ! I am going to setup a 20km PtP LOS link with LHG5 at both ends. May i know please that LHG5 is suitable for good/excellent solid reliable connectivity between two sites at this distance? Any valuable suggestion would be appreciated before going to place an order for LHG5. Thanks.