AP-SM link >15 miles?

Is it possible to make AP-SM link with distance more than 15 miles?
Is 15 miles only software limitation?

Yes, the maximum 15-mile distance is limited within the software configuration interface. If you could find a way around the limit by poking a value directly into a file from the telnet interface, you may then run into other issues. But it’d be fun to try.

we have several 18-20 mile links on 900 quite sucessfully

I had assumed P_a_l_o was referring to a 5 GHZ AP. Sorry neither of us made ourselves clear. The software-imposed limits are currently:

900 MHz: 120 miles
2.4 GHz: 30
5.2 GHz: 15
5.7 GHz: 15

Prior to software release v4.2, 2.4 GHz had also been limited to 15 miles.

I don’t know the technical reasons for the 15-mile limit for the 5 GHz bands. Maybe it’s to keep all of us from trying to mount the SMs on larger reflectors to make use of a higher setting.

How far would you expect a normal 900MHZ AP to a normal 900MHz SM go? both with the built in antenna’s (not the conectorized versoins). What are average in the field throughput figures to 1 SM, both up and down speeds please. thanks

The integrated 900 MHz antennas are sized to produce maximum radiated power for the U.S.; adding an external antenna on the connectorized version helps by reducing interference by narrowing the beam pattern.

With no interference, Motorola says the 900 MHz units can go 100 miles. The fresnel zone at this distance puts the starting tower height at 190’, but earth curvature adds another 1,650’. That’s a tall tower.

Aggregate speed is about 2 Mbps, a third of the 2.4 and 5 GHz units. Throughput is likely half of that, but I haven’t tested this in the real world, and it makes a difference how you have DataDown% set at the AP.

With new firmware it is possible to set max distance in APs to 30 miles.

That is correct, as of 7.1 all radios are capable of being set at 30 miles(besides 900 which can do more). As always, only set the max distance a little further than your farthest SM.

We have several links equal and beyond that.
5.2 we have 15.7 miles
5.7 we have 18.7 -26.4 miles

This was all prior to the firmware upgrades. This is pre 4.xx