Wireless Link - 225 meters

A

alkit

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Hi,

After much experimentation, I finally managed to set up a wireless link between my house and my friend's flat.

Equipment on my side:
Ubiquiti Bullet 2 CPE device connected to a 24dbi 2.4ghz grid antenna mounted on my roof

In between:
225 meters total distance between the 2 antennas. Around 2 or 3 thick trees. They are too high to get line of site.

Friend's flat:
Arc FreeStation 2.4Ghz 15dbi Panel CPE device

I have managed to establish a link at around -65 dBm and have CCQ at 70-100%.
The problem is that the speeds I am getting are terrible. Max speed goes to 3Mbps. This speed is crazy slow for file transfers.

What factors could I look for that could be causing the bad rate? I know my antenna has been sitting around for a while - could it be a fault with the antenna? Could it be something to do with the Ubiquiti device?

Please advise the best way forward to improve this connection speed.

Thanks!
 
You can try and change the 15dbi panel to a grid antenna. But if you don't have clean line of sight (i.e. no trees in the way) you'll always struggle.
 
you can hard code the speed on the two CPE's as it is on auto it will select the lowest bandwidth rates to enure lower packet-loss. You might find a higher amount of packet-loss by increasing the speeds.

No line of sight will always create issues
 
I guess it all depends on your throughput requirements and the frequency that you use. With 2.4 GHz equipment noise is always an issue and will have a major impact on throughput. The fluctuating CCQ indicates that the link could be affected by interference from radios on nearby or similar frequencies. The equipment is also based on a single polarity radios. Maybe try to use the alternative polarity to what you are using now? in other words turn both antennae through 90 deg. Also ensure that you are observing the correct polarity currently.

You also run the risk of compatibility issues by mixing brands. The NLOS at 250 m should not be an issue really with 2.4 GHz radios..if the radios are properly aligned and allocate a clean frequency. You can try to reduce the channel bandwidth from 20 MHz to 10 MHz or even down to 5 MHz, this will reduce spectrum requirements and reduce the impact of noise, also choose a clean part of the spectrum.

If you want a more reliable link: Invest in 2 x 2.4 GHz Nanostation loco's, these are MIMO dual polarity devices. Obviously you still need a clean part of the 2.4 GHz band for reliable throughput. 5 GHz will not really work with NLOS applications.

http://www.scoopdistribution.co.za/product_info.php?cPath=101_75&products_id=1029


Good luck...
 
Last edited:
The only real cure for lack of LoS is a chainsaw.

If you don't have an unobstructed view of the other side you will always struggle. Maybe try find a common high site you can both connect to that has clear LoS.
 
Trees are buggers when it comes to wireless signal from what I understand, when it rains it may get worse as the water collects on the trees, causes interference on the signal, dunno if thats 100% accurate sure someone can correct if wrong.
 
Turn your power output down. You're interfering with yourself.
 
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