Best solution For GPS Sync on Water Tower

I am working on designing a deployment of 4 90deg sectors and I am curious if anyone has experiance or sudgestions on setting up GPS sync for a water tower.

My basic config details:

APs will be around the catwalk (widest part of the bowl) seperated by the entire tank.

APs will be at 0, 90, 180, 270 degress

APs are approx. 110' AGL

Desired service area is 0 to 5 Miles

Will be using ePMP1000 GPS Sync 2.4 Connectorized APs (Unless they are not capible of this configuration.

My main delema is the I am not sure how the internal GPS will work on the units seeing as how at least one of them will have an obrstructed view and the UGPS does not looke like a good option due to the seperation of APs and the quantity.

My best Idea is to use a CMM but I would like to use a third party switch we have already had deployed in our network elsewhere. Is that even possible? If so, what is the best unit to use?

Any suggestion?


If you already have the radios, check the firmware version on the internal GPS - if you have one with version AXN_3.20_8174 then you're good to go.  The AXN_1.51_2838 and other 2xxx versions are a different (older) GPS chip that works fine, but the 8174 is GPS+GLONASS, able to see and lock onto more satellites more readily.  (here in our office, first floor center of the building, I can get one of them running with sync from internal GPS, WITHOUT an external GPS antenna connected, seeing 15+ satellites sometimes)

That being said, if you want to centralize the sync but use your own switch instead of CMM then Packetflux is worth a look.  You'd need a sync injector (4-ports sync and POE),  30v power supply, SiteMonitorII (not strictly necessary, provides web UI to control/monitor injector) and a SyncPipe GPS unit.  About $300 maybe.


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I think I failed to mention that the switch we have is PoE. Would I still be able to use that line of products for that?

No, sync has to come from internal GPS or injected 1PPS on the ethernet cable along with power.  I'm not aware of anything that will layer the GPS pulse on top of existing POE.