On Fri, 3 Mar 2017 23:37:48 +0000, tony sayer wrote:

Try telling the 2.4 GHz point to point links that are here that.
One is 6 km the other only 4 km. Another site has around 20 km
and 15
km. Rain, hill fog, snow or all three didn't stop 'em working.

Do they use 2.4 GHz?

They certainly did, I'm not sure if they are still on 2.4 Ghz as
the
kit has changed a couple of times since the orginal installion 15
odd
years ago. That used Cisco Aeronet 350 series bridges, 15" dish
one
way and "long" yagi the other.

5.8 Band C is the preferred way nowadays works much better for longer
range links. We have got one in daily reliable use over some 18.7
miles...

Before the fibre arrived the backhaul was over a licenced 5 GHz link
of 25 miles. Was supposedly doubly rendundant but who ever selected
the kit didn't think as well as it did, as it found a way to fall
over. Only serious outage, possibly the only one short of (rare)
power loss at the sites, over several years. 100 Mbps IIRC.

--
Cheers
Dave.