GPS Synchronization Question

I'm trying to move all of our distribution over to ePMP1000 radios so I can utilize the GPS sync. All of my new towers have both 2.4Ghz as well as 5Ghz ePMP1000 equipment. 

I'm trying to get everything synced up, and I have a quick question. I've read over all the documents about the ABAB frequency planning. I'm trying to do an ABCD deployment, which is apparently the preferred deployment? Well, we do have some competitors in our area, and I am wondering, since I may or may not be able to use the same ABCD channels on every tower, how can I set up my deployment as efficient as possible to allow synchronization from colocated sectors as well as adjacent towers? Some channels may be too saturated to reuse on an adjacent tower, so I wanted to see what you guys recommend.

tower 1  ABAB     tower 2 CDCD is what we do, and works well.   

a phone call, Christmas card and a few lunches with your competitor and getting a good channel plan together is the best.   

 at your borders, if you at all possibly can come up with a plan to not bother each other.      if you guys don't you both suffer and the only loser are the customers.  

if you can agree on equipment and sync parameters, even better.   

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As Chris has indicated, ABAB/CDCD deployments, as discussed in are recommended. The use of antennas with F/B greater than 30dB is critical.

In the case of ePMP, we also recommend minimum of 5MHz guardband between adjacent sectors (5MHz guardband between channel A and B, for example).


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How can I verify if the GPS synchronization is working? As far as the ABAB and CDCD channels, it has to be set to one of these four specific channels for it to work properly, correct? I am keeping a 5Mhz separation on my channels, but on some towers I'm not able to use the same four channels due to noise (mainly in the 2.4Ghz band). Any tips on what I can do to maximize my efficiency?

you can use ABCD at the same tower if you need to, and just use sync to protect against co-band noise, as well as sync towers together. 

ABAB  CDCD  is just the start model to work with.   most of the time, it will be good to go. 

 you can do ACAB  or any other combo you want, the trick comes into keeping your maps together to know your are running the reruse correctly.      the underlying catch,  the AP set to channel 2407 and is set to front, it cannot hear another sector at 2407 also set to front, it can hear two of them set to back without trouble, but never another front.  if it does, do what you can to keep it in the 90s so they don't bother each other.   

your free to reuse the channels as often as you'd like in any pattern you'd like provided you keep to like mode and frequency from matching.     if you look at the gps guide, you'll notice the front and back marks and their placement.  along with GPS, to get your max out of the system, take some time and read up on tips for sector tilts and cell coverage concepts.    good pre-thought can really reduce the impacting noise and let you have limitless growth.     GPS snyc is couple with well planned out sector placement and tilt will get every drop of performance you can expect from epmp line.  

we have deployed ABC   DAB  CDA BCD setup with wonderful results too, three sector setups are much more challenging to plan but you'd be able to have many more sites in a tighter area,  we have 12 - 3 sector 2.4 ghz towers in an area only 25 square miles..   larger sites are best served with 4 sector setups.      

to know if your GPS is working, make sure your config is correct, front and backs marked and turn everything on.    lock a few CPEs and watch the upload, you should be able to achive equal RSSI on both panels and maintain strong modulations, if your in doubt and want to see what happens without GPS, turn one to flex mode and do some over the air speedtests.... you'll see both panels suffer significantly.      repeat the test with both APs configured properly and you won't see a problem with one sector going to full air time. 

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