2 900mhz towers 2 miles apart

is it possible to have 2 900mhz towers about 2 miles apart without causing havoc on each other?

i know one of them uses 906 for north and south and 915 east and west

could the 2nd tower just switch the freq that are looking at each other?

Sync 'em and configure all with the same
Max Distance
Control Slots


use the frame calculator tool to determine alternate settings.

In addition, coordinating frequencies so that AP’s looking at or facing away from each other are on the same freq will help

use channel 924 only and you will be fine.

Not if the other tower is out of sync.

Why do you believe sync is required on the 924 location? It is my understanding that it is always best practice to have all tower locations in sync. But if no other location is using the 3 channel, sync is not required and will not be an advantage in the setup described.
Sync’s only advantage is to allow the reuse of the same spectrum / channels.

That’s what we thought too, however that’s not how it works in the real world.

The bleed over is great enough it will cause absolute havoc on your other APs, regardless of channel separation, especially that close.

We got away with it when our APs were 15 miles apart, but a location we added only 7 miles from another AP made a huge mess - it was on 94 and made client connections miserable on the 906 AP 7 miles from it.

Canopy was designed with synchronization in mind - with as cheap as a sync pipe is now why would you want to do it any other way? Do it right the first time and be done with it.

I agree sync everything, but my experience has shown and currently shows that the 900mhz Canopy solution does [u:11e0p2ic]not[/u:11e0p2ic] “bleed” [u:11e0p2ic]very[/u:11e0p2ic] badly in adjacent channels. I currently have several location that are from less then 1 mile to 5 miles from the next tower site all without sync utilizing the 900mhz band. All locations are using omni antenna on the AP. The 1 mile site is even using a 900mhz SM as it’s BH feed. The SM is at the same height vertically and only a few feet away horizontally.
This obviously requires very good antenna, and channel planning.
Again sync everything, it is cheap, best practice and makes everything much easier, but it is not required.
I would say if you are going to have any two sites that are within 20 miles without a physical obstacle such as a hill in between on the same or adjacent channel space then sync. I have experienced self interference at 28 miles between towers but both locations are at 300’.
I have seen a Canopy 900mhz link work at 64 miles so self Interference is possible at even that distance. Heck, with the power levels the link was at you could go twice that. Ever wonder why the AP distance shows up to 120 miles?

Out of sync AP’s will work, that is true. This business is hard enough, why make it harder? A un-sync’d system is compromised from the beginning and will become more and more unstable as users are added over time.

The easiest way to know if sync is required is to use the AP in SM mode to do an AP Eval. If any AP’s show up, you need to sync 'em all. However, if they have broadcast AP eval data turned off it becomes more difficult.

If you are dealing with another provider, NEVER go to them and tell them they are causing you interference. Tell them that you are causing them interference (even if they have not realized it yet), and you have a solution.

What set Motorola canopy apart from the rest is SYNC… I don’t see why anyone would use canopy products without sync.


I see you guys use 900 Mhz? We have come out with a 17.5 and 14.5 Dbi Yagi antenna. If you’re interested please go to our web site and take a look. If you have any questions give me a call.


Take care

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I apologize for the off-topic nature of my response.