Tropical Wireless - How To Deal With Lightning, Fog And Torrential Rain

A member is asking about deploying wireless surveillance in the tropics. While he notes the geography is flat and rural, the big challenge he faces is the weather with lightning, fog and torrential rain being common.

Should he use wireless here? If so, what special steps or products should he use?


I'd first ask what is the tolerance for signal interruption, and what is the application "worth"?

Also, what is the distance to be covered, and approximate throughput required?

On the low end would be Ubiquiti of course. Proven, works, cheap.

In the middle coule be a mesh setup with a repeater arrangement in the middle (if possible).

At the high end would be microwave towers. More or less guaranteed to work 99% of the time, but not cheap or easy.

This is one of those problems that is "easy" to solve, it's just a matter of budget.

If he's that worried about environmenta; conditions, I guess it might be worth maybe putting the radios in NEMA enclosures with the antenna's poking through well sealed holes and surge arrestors on the antenna wires. Antennas would also probably need to be sectored or omni, main point being rounded and avoiding panel shaped ones due to wind load. Just my two cents.

I think wireless should still be a viable option. Keep the links short in distance to maintain a good 15-20db fade margin. Ground all the equipment really well and potentially add some redundancy depending on the application.

Make sure all is bonded for proper drain, bonds, grounds. The lightning issues you have, would be Ring wave at different frequencies (33KV/sec.) and this would turn the wireless device into a capacitor. Energy waiting for a place to drain.

Insulate , Shield , Drain all area metals and what ever it is attached to. Verify that everything around it is bonded to ground and verify that the lightning rods around the area are good. For a good review go to NEC 70E , NEC 760

He should get training first or hire a trained RF technician who knows best practices for installation. Most sites (bahamas, puerto rico, dominican) I see with problems are due to lack of training ie. antenna polarity, alignment, connector protection, etc.

A properly designed system will take into account rain and fog, that being said lower frequencies such as 900 MHz, 2.4 GHz and 5 GHz are not greatly affected by rain or fog, but proper path profiles and link budget calculations are a must for any wireless system.

Lightning, 3 words... grounding, grounding, grounding...