Suddenly lost GPS

a cluster of EPMP2000 on 4.5.6 with 90 degrees antennas.
Worked flawlessy till sunday.
Now all STA down because no gps sync

I checked and:
1st sector: latitude/longitude NA, 0 sat
2nd sees a lot of sat but SNR to 0
3 works OK
4 as the second.
what can I check?

I have had the same problem for years and I understand you.
I no longer have the desire or strength to seek help from Cambium.

I am very sorry that you are going through the same thing that I have been suffering for years.
These from Cambium have no hearing and do not fix the flaw in the firmware.
For the same reason I stop buying the same under that brand and migrate to another brand.

Welcome to the club. Sync over Power is the only real solution.

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Which then also precludes being able to use the 3000L, and forces us into buying 3000 MU-MIMO for $1,000+ ea it you want the option of Sync over Power.

Plus, if GPS isn’t going to work reliably anyway, then why not let us use SM’s (without GPS) and use RFE Horn antennas as APs? But no, they’ve removed that feature from the SM’s, in order to try to manipulate us into buying GPS AP’s. However, in reality, what it actually accomplishes is force us to go back to purchasing another brand. Genius “sales team” business model.

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Yep, it’s a real issue (gps reliability on epmp, I had similar issues with 1000 gear). Open a ticket with Cambium and they will send you new pucks that may help. The pucks aren’t a panacea though, something is obviously broken and it’s been happening for way too many years at this point.

Hello. Thank you for you answers.
So there is no real solution, no official solution from cambium?
It was working absolutely fine… then OFF.

I have been waiting for a solution for 3 years and it has been a waste of time.
There are only two reasons for GPS problems.
1.Cambium does not want to solve this and forces you to buy more accessories from them.
Or newer generation equipment.
2. They do not know how to solve a problem.

Best regards

I agree in every way… the GPS issues were never a real problem for us (we have always used sync-over-power) until the 3000L came along and if they had more antenna options for the 3000 we simply wouldn’t have bought 3000L, a 30v , filterless, no-sync-over-power radio with unreliable onboard GPS sync that wouldn’t even need to exist if they didn’t disable PMP (and probably GPS sync) in the still expensive 300 CSM.

So there is no real solution, no official solution from cambium?
It was working absolutely fine… then OFF.

For us “trying things” that require hours of prep and money (not to mention angry customers) for tower climbs to move / replace pucks that may or may not be the problem it just isn’t worth it when we can just do sync over power.

Even if you are going to primarily use ePMP’s onboard gps I would highly recommend that you pick up a packetflux sync injector and sync box ( about $300’ish total) that will allow you to provide/restore sync in an emergency and, depending on how you are powering your AP’s, do it without having to climb the tower.

PowerInjector Plus Canopy-Style Sync - Gigabit Version - PacketFlux Technologies $169.00
SyncBox Junior Basic Version - PacketFlux Technologies $99.95
48VDC 2.5A Power Supply for various products - PacketFlux Technologies $35.00

That will power/sync up to 4 1000/2000 AP’s . It never fails, we started with Canopy 14’ish years ago and in those 14 years there was only ever one time GPS failed. Note that one of the reasons it may be so bullet proof is that the GPS receiver/antenna is down on ground were there probably isn’t as much interference as there may be 100’s of feet in the air.

Unless you have 3000L…in that case you’re spending lots of time/money/angry customers climbing the tower… possibly over and over and over trying to move the pucks, re-orient the pucks, build little rain proof houses for the pucks, replace the pucks, disconnect the pucks, reconnect the pucks…

We did just recently receive a batch of the 3rd gen GPS pucks from cambium and have re-deployed a few 3000L’s with the new pucks… as you have noted, these things can work for a long time before the fail so only time will tell if the new pucks are the magic bullet.

The problem is not about the GPS packs from the Cambium I moved to Ubiquita and the Mimosa devices work perfectly. Never a single outage with them. What is happening with Cambium is a clear picture that it is a software failure or a tactical decision.

I hope the Cambium people are taking notice of issues like these.We’re busy running a new GPS P2MP pilot for a big project and we’ve barred Cambium p2mp/p2p hardware due to all the issues we’ve experienced.

I don’t get why Ubnt/Mimosa GPS stuff just works for the life of the link but Cambium seemingly cannot get it right under any iteration of their radios.

Not sorting out things like this will hurt your bottom line eventually.

When I present it to ePMP and the benefits of GPS sync it is not said that I need the same more except for the pack antenna.
I quote "Cambium is inherited from Motorola GPS sync that goes with CMM.
Our engineers have gone a step further, thinking of their loyal customers and enabling sync via a GPS pack antenna (and raised it above their heads like a gold medal in athletics) "
I asked if all that was needed was answered to me of course.
My question as to why this antenna looks so gentle is whether it can survive outside for years, answered of course but don’t worry there is another antenna in the device that you can see without disassembling the device.
The tension has been going on for three years now and the problem with GPS sync Cambium has never been solved.
The seller-buyer relationship should be honest and fair but in this case it is not.

Please submit a support ticket and we will help you one way or another. I will post an update on this issue here shortly.

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There are a mix of topics here so I am going to try and organize the responses here.

  1. First and foremost, GPS issue on the 3000L. Yes, we decided not to add a puck to the box as we felt that the onboard would be sufficient for tracking and locking. On top of that, I forget which firmware but we did have a clear bug that broke our communication between the receiver and our main chip. This caused GPS to be lost. We fixed that in 4.5.6 and later. However, even with a working solution and a puck, there have been reports of intermittent issues on the 3000L. Here is what we have done: 1a. We included a GPS puck in the 3000L as of October. Between inventory in the channel and cutover this takes time to get to your hands but it should be out in the market. This puck was added under two variations. A small batch went out with the same puck we use on the full 3000 but then we shifted to a much better puck with better noise cancellation. In a couple of days, I will post images and specs of all the pucks that are out there. All said and done, a software issue made the GPS problem far worse than other platforms and combined with no puck in the box it has been very challenging for you. We are sorry. However, we do feel we have rectified the situation with a solid puck in the box.

  2. General observation of GPS receivers/pucks - I haven’t climbed any tower but we suspect location of ePMP APs with onboard GPS chip and LTE interference has been a cause in the past for GPS loss. Additionally, we have seen that once GPS is lost on the receivers, it takes a very strong signal for everything to come back to normal. Sometimes, this doesn’t happen for a long time. Why is the signal lost in the first place, we are not sure at this stage. Our response is to provide a better puck so that the signal is good enough to begin with. In all fairness, using packetflux like devices is the right answer for ePMP2000, 3000.

  3. ePMP3000 - If you are seeing issues, ask for the new puck please. If you don’t want to use GPS sync, flexible scheduler is coming.

  4. ePMP2000/3000 - GPS issues. While there are reports such as the one above, in the big picture we have not heard/seen a flood of issues on these products. Very early on, we even had a customer who proved to us how LTE interference can cause the 2000 to lose sync. At this point, in these scenarios if you are seeing the problem, submit a ticket and we will address it.

Long story short, despite the continued comments from some users about how Cambium does not care (you know who you are) or how we are trying to squeeze money out of you etc…etc, we DO CARE. We care about every one of our customers small or big. However, if we jumped on every grievance you post when you are having a bad day and want to take it out on the vendor, we wouldn’t have time to work on real issues. Please submit a ticket. Our support team is trying to help you. Let them ask a few basic questions, if you think you want to bypass that and get straight to the GPS issue, say so. The GPS issue has been a pain. Period. We are trying everything to address it.



Sakid you have to understand.I cannot tell a client or an IT Manager or even my manager at work “Vendor knows there’s a problem ; No ETA . You will just have to suffer DT and erratic connectivity for a couple more years possibly” .

They will either just find a new provider or ask to remove said equipment and replace with properly functioning equipment which we’ve been doing over the years.

Unfortunately the GPS sync cat is out of the bag for Cambium and no amount of PR or spin can save it at this point.FYI virtually all my competitors have also ditched 2000/3000 platforms so the news has spread through the grapevine.

4 posts were merged into an existing topic: ePMP GPS rant

please add option like 450m: free run then GPS


Ehm… sorry
but wich is the solution?
we use the AP2000 with external gps puck.

Try updating to, if that doesn’t work, open a ticket with support.

  1. In a couple of days, I will post images and specs of all the pucks that are out there.

Are the images / specs posted somewhere and I’m just not seeing them ?