ePMP GPS issues

@brubble1 wrote:

Just FYI

 The SA being enabled seems to be what caused all my issues.

Yet another good reason why a simple 802.11 site survey would also be good to have, in addition to the SA.  Enabling the SA is a duck shoot in a way.

Also - since it is recommended to 'disable the SA when not in use', I think that enabling the SA should always have a timed option by default, meaning it should self-shut off by default, unless we specifically tell it to remain on forever.

In other words - if it's recommended to "disable when not in use", then 'On Forever' should NOT be the default setting on a SA..  So, I think when we go to enable the SA, the GUI should say something like "Enable Timed SA for 5m/10m/15m/30m/60m/Forever* (Warning: may cause pon"f'ar)"

At the very least... if the SA is 'on', there should be some indicator on the main status screen (like a SA logo up by the Green Globe and the Green GPS/Location icons... maybe a 'SA Running' icon up there?

Regarding the 3000 & 3000L GPS instability which some people are reporting... I just thought I'd post that our 3000 & 3000L have been very stable.  I'm just about to upgrade a few AP's to the latest 4.5beta, and I thought I'd post these two images, showing GPS uptimes since our last upgrade/reboot.

39 Days since we rebooted this 3000 AP - with no GSP Issues in the last 39 days.


67 Days since we rebooted this 3000L AP - with no GSP Issues in the last 67 days.


These are both going to 4.5-RC54 today, so the uptime will get reset - but I thought I'd post that not everyone is having GPS weirdness, and that (at least for me) the GPS has been rock solid on our 3000 and 3000L APs.

Hi all,

YOu can reach me at fedor.trutsko(at)cambiumnetworks(dot)com if you'd like to test private firmware with the GPS fix for ePMP3000L.

We would really appreciate your help and your feedback.

Thank you.

Would using an external GPS + cnMatrix away from any LTE antenna help?

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It will definitely help! Especially with a new GPS-puck.

Is that the standard GPS puck that ships with the ePMP3000?

It’s got a relatively short cable - can I pop an extender cable on it? Any cabling distance limit?

As I’d like to install the puck on the roof of the building the cnMatrix would be installed in. The actual ePMP radios are installed on the tower next to the building 25M up.

30 meters I believe for CNM and a puck.

Yes it is. There were 3 generations of them. I’m talking about the last one.

Yes you can add an extender. But actual distance will depend on cable quality and connections losses. I suggest to experiment with available materials. 25 meters is significant distance.

Am I better off using cnPulse - I’m assuming since it’s Ethernet 100m limit applies?

We have a water tower where we’re colocated with 3 GSM operators. You can imagine what level LTE signals are there. Considering there’s lots of metal constructions, antennas human high, etc, the harmonics from LTE totally destroys GPS signal. It didn’t catch any satellite for even 1s there. We use 3rd gen GPS pucks and have placed them under the water tank some 5 meters below the roofing. We use 10 meter extenders with H155 coaxial cable, and so far this tower did’t have any GPS problems. Watch for very good characteristics of coax shield. Lower grade cables get easily penetrated.

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