ePMP 1000 Freq Deployment

I always seem to have problems wrapping my head around proper freqency deployment so I need some help.

We have 2 water tanks that we have a few old 2.4 Tranzio APs.  We have upgraded the West tank to ePMP 1000 (GPS synced).  We have 3 120 degree sectors.  NE, NW, and S.  We are using the 5.8 band (FCC).

We are about to upgrade the other tank to the East to ePMP as well.  Same sector layout.  (See map below for positions in relation to each other)

I know the APs have freqency reuse options but I don't know if that applies to 120 degree antennas.  I figured that was for back to back antennas or 90 degree layouts.  Can I get away with using the same freqencies seeing as the APs are GPS synced?  

How should I layout my Freqencies?

Layout Summery:

Freq Range: 5.8GHz (FCC)

Channel Width: 10MHz

Equipment: ePMP 1000 (GPS Synced)

Antennas: 120 Degree.

Azmethas: NW, NE, S

Any help would be great.  If you need more info just ask.


We do not recommend frequency reuse with 120 degree sectors. However, if you sync all three sectors, you need no more than 5 MHz of guard band between the sectors. If you don't sync them, then we recommend 2X the channel bandwidth as the guard band. For example: if the sectors are running 20 MHz channels, then we recommend 40 MHz of guard band between the adjacent sectors. 



The key to frequency reuse (given that APs are synced and configged the same) is to minimize locations that can see two APs on the same/overlapping channels, unless one is significantly stronger that the other.  Assuming that the relevant radio settings (sync, range, up/down ratio, frame size) are the same across all APs in question:

Two APs on the same channel can aim AT each other from two different towers as long as clients of one don't see unacceptably high signal from the AP behind them.

Two APs on the same channel can aim ~180 degrees different directions from the same tower, bearing in mind that clients well off-axis may see both at similar strength.  (for this reason same-site freq reuse is usually not reasonable with 3@ 120 degree sectors - can't reuse freqs on adjacent sectors, must be a gap between them)

Two APs on the same channel on different towers can be aimed in different directions (IE 90 degrees difference), again understanding that clients positioned such that they see both APs will suffer.

Two APs on the same channel can aim in the same direction from two different towers, ONLY if clients of one will be unlikely to see the second tower behind/beside 'theirs', otherwise SNR sucks.

All of that being said, hopefully you can find at least 4-5 usable 10mhz-wide 5ghz channels.


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