Will ePMP 4500L support sync over power

Obviously sync is not supported in firmware yet anyway, but I’m really hoping the answer is “eventually”.

We’ve always had reliability problems with the GPS pucks on ePMP radios. Sync over power has solved those problems for us.

If they don’t support sync over power we won’t be using them. Just about any Access Point on our network can see a dozen other access points we can not function without Sync. ePMP’s horribly unreliable onboard GPS (even with the new pucks) combined with cambiums repeated stance of denying there is a problem means there is no way I’m using any more of their products that can’t sync over power.

At one point we removed every single PTP 3000L from our network because they can’t sync over power. About 3 months ago I found myself in a position where I needed to split an AP but there was no antenna solution for 3000 that would work in this instance. So, knowing better, I split the sector with 3 3000L’s and RFelements asymmetrical horns. I used the new and improved GPS pucks cambium had sent me and… as expected constant loss of syn on all 3 radios on 130ft stand pipe water tank with no other devices on the tower except ePMP AP’s and an AF11 , no one else has hardware on this tower and the nearest cell phone tower is 6 miles away. We went up the tower 3 times to replace, move and adjust the pucks but ended up having to replace all 3 3000L’s with 2000 APs (because they could be used on the horns already installed and they can do sync over power).

That’s a two hour average on the graphs so lots of drops of 2 hours or more and lots and lots and lots of drops less than 2 hours.


Want to hear something scary ? In the last 2 months I have had 2 3000AP’s on two different towers stop working with sync over power. All the other APs on the the tower /injector work , we swapped ports on the sync injector between working/nonworking APs and swapped cables between 2 APs but the problem stays with the AP. One of the 3000AP’s started working again after powering off for a while and being powered back on the other 3000AP(different tower) would no longer work with sync over power no matter what we tried ( 3 other AP’s on the same tower / injector working fine) so we change it to onboard GPS, that lasted a whole 2 days before onboard gps started losing all sats so it had to be replaced (and that was a pain). Lots of 2000APs and even a few 1000APs out there on sync over power that have been working fine for many years but as we slowly replace them with 3000’s it looks like 3000’s sync over power may not be so reliable.

Unfortunately, it does not have hardware support for sync over ethernet. That being said, Cambium has made some improvements to its onboard GPS sync.

I would rather have sync over power than onboard sync any day! Regardless of the GPS improvements, relying on the onboard GPS has been a very big problem almost as big as not having sync at all. At least with a PF solution I have options, could even be convinced to toss in a CMM or cnMatrix if I had to, but not if the option isnt there.

Maybe a different SKU and see which one the community buys the most of, assuming the SKU difference is obvious like -GPS for onboard GPS???

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Ahh so like 3000L the L means “Loses Sync” instead of “Lite”. Seems they could save a few $ and not even bother with including onboard gps on the L radios.

How could they possibly improve something they have continually insisted has no problems… and second are you saying they made improvements to the onboard GPS on 4500 vs the all the previous ePMP platforms that didn’t really need any improvement because they are were already so awesome ? Because from 1000 to 3000L our imaginary onboard GPS issues have only gotten worse, not better.

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Not trying to be snarky - but I was thinking the same thing. If Cambium doesn’t think there has been an issue… then what did they improve? Or how could those improvement be expected to address the reported issues, if they don’t agree that there are issues?

For what it’s worth, we’ve actually had very little GPS issues, including 3000 and 3000L with the pucks they shipped with (whatever flavor those are?) but for my 2c, the integrated GPS has been pretty good. Obviously others have different experience, but just saying it’s not horribly broken for everybody, everywhere, all at once.


I guess I overstated the GPS improvements as being “considerable”… but they do have a new improved GPS puck that adds filtering… aside from that, the GPS chip is the same in the e4k and e3k… so no real improvements or changes there.

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