The GPS chip that Cambium uses has a ceramic resonator antenna as part of the package. So in theory it can work without an external antenna. We have tested this and as you observed it is not reliable for this application. By adding the external antenna and reading about this antenna from the manufacturer, we implemented a virticle mounting policy. This means we mount to virticle surfaces only, cable pointing down and for us only facing south.
This allows our epmp3000L radios to perform properly and the do not loose sync.
We still have packetflux timing for our 1000s and 1000-lite APs despite having the internal gps as backup.
Make sure you are not using the round gps puck, only the square ones.
Screenshots from my previous post say that there is a terrible omission in writing the firmware for GPS It is impossible to hear it detects a large number of satellites and the SNR is zero. How is it even possible to hear something that is heard on the lita and the signal does not exist. Funny, isn’t it.
All GPS packs are square and I turned them off as a potential problem, I transferred them to Ubiquiti airFiber links, they work there by
several years without loss of GPS.
regards
Snr of 0 isnt as bad as you think. Thats why they provide the rx signal strength too.
Think of the satellite showing up at snr 0 as the same as listening to someone speak in a very noisy environment, since you can hear the other person a bit does not mean that you can hear them above the noise by an appreciable amount. But you can hear enough to know that they are there.
Also it takes 4 satellites with an snr of 6 to make the fix needed for gps timing as per the firmware. Ofcourse if you have some LTE cell towers near (relative term, think if your cell phone has signal in lte mode then its near) then you can desense the gps antennas (both internal and external) and thus not get gps timing pulses. We have one tower where we had to make a metal box open on one side for the gps antenna to prevent the new cell tower from mangling the gps signal at the antenna. The box needs to be twice the width of the antenna, twice the height and no more than about 2 inches deep. This prevents the box from hindering the gps signal. We just used 16ga steel and havent lost gps sync on that tower since.
Please don’t misunderstand me.
I don’t need lectures in electronics and radio engineering. I am 51 years old and I have been with this subject since the time when many who are help desk in Cambium were not even born.
Additional armor adding a mesh or steel box is unnecessary if the firmware is written properly and is not.
The same ceramic antenna active and other passive components that were mostly made by the Chinese are used by everyone.
The topology is the same because it is done as the component manufacturer suggested, why change anything.
Why doesn’t the GPS crash on the Ubiquiti device.
Not because someone knew how to make firmware properly.
Though I am not yet in my 50’s do not discount what others say, we come froma wide variety of backgrounds and may have an idea or two about the problems.
The GPS chip in question comes with or without a ceramic resonator cavity antenna. The cost difference between the two is literally a couple of pennies. Cambium chose to provide an option of not using an external antenna but include an antenna in the box (except for the e3kL). For what its worth, the sync over power has been solid without issue and the onboard GPS is a toy that is nice but really not necessary and could be dropped in favor of using only sync over power but the point is moot.
The GPS didnt crash until Cambium trued to make sure that the N based devices didnt get left behind on the upgrade path to AC making sure you didnt have to run multiple generations of APs on a tower (which by the way UBNT devices still have problems with) saving you money and costing Cambium sales revenue. You dont have to forklift your network just to get more throughput to a sector not a whole tower as you can upgrade just the sector you need to. Again costing Cambium revenues that UBNT forces you into. Yes Cambium is more expensive up front but you also get support from Cambium, just try to call UBNT and get a person to help you in a meaningful way including unlocking a shell and letting you see whats under the hood while fixing a problem.
The chip manufacturers plant location is simply a governmental issue that drove companies to place those facilities where it was economical. You want chips made locally, then pressure your authorities to grant incentives to manufacturers. Again moot point.
Compairing UBNT and Cambium technologies and calling them the same is like calling an apple an orange. They are based on the same standards and use compairable chip sets but they are not the same. Open a few up and compare them and you will understand.
Firmware stability? Really compairing UBNT to anyone regarding stability is an industry joke. I have an UBNT link that has more down time than a politician! And yes one bad egg shouldnt spoil the batch but isnt that what your claiming?
Building of firmware, well since both devices run a stripped down flavour of linux and add the features of choice it is really an implementation choice. Do I use dnsmasq or bind? Do I use isc-dhcp or udhcp? Apache or nginx? J-node or just use http calls? Also consider the base flavour and its code base, run a couple revisions behind but is really stable or run bleeding edge? There is also the mentality of one root and never upgrade until no other choice path.
There are really too many options to try and say one is the best and how they interact with each other can be both frustrating and amusing.
Before you claim I am blind to the faults of the epmp series, I am not and Fedor can confirm that I have no problem pointing them out. But I also provide my insight as to what could be done about it as well and not always in open forum. But I am not here to fight with you.
We are not here to fight but to discuss in the name of progress.
At least I want to resent anyone.
And I don’t want anyone to insult me either.
My personal position and I do not want to lead anyone to make the wrong decision.
The problem with GPS has been there since ePMP.
And no additional nets and steel boxes are needed, this can be solved by neatly writing the firmware.
If nets and these steel boxes were needed, Cambium would sell it properly as its product and it would cost at least $ 100 per piece.
I begged someone to look at that GPS.
A colleague talked for days with support from Cambium regarding the GPS problem. Once he told me I’m giving up, which firmware, which antenna is south
do you have a GSM, TV or Radio transmitter on the tower is it round or square etc.
Have you tried to move the antenna.
But the firmwre team made sure the web looked a little different (very important)
And version 4.6.0 comes out when someone there has a problem with the characters%, $, #, & / and the like.
Version 4.6.0.1 is coming out urgently!
Is that the support we are talking about.
Why did anyone even touch that?
When there are more important problems.
Cambium inherited from Motorola a reputation that has seduced many like me and we will see how it continues.
Everything Cambium has done in terms of fixing GPS problems is ridiculous.
Older firmware versions had synchronization for up to 68400 seconds or 1 day.
Someone raised it to 684000 seconds or 10 days and it is considered a solved problem.
The solution to the problem of dying of laughter.
Best regards.
OK - well, as I told you in private message already Zica, you’re doomed to no solution then.
Cambium is trying to help and has asked you multiple times for:
Your AP Support Files
Your Support Ticket #
You are refusing everyone’s help, and instead are choosing NOT to provide anyone with the technical info they need. So, good luck with that working out for you.
I ask the administrator to delete the post before one of the cambium engineers finally publishes it
When and with which version of the firmware the internal and when the external antenna works,
Why is there no internal or external antenna option in the settings?
And of course still no one has ever answered my question whether they know how to solve GPS outages or they don’t want to solve them!
Regards
Just to let you know that a few minutes ago I dropped GPS sync on two AP 2000s
Clearly sunny. Before it turned out, the signals from the satellite were brutal.
The other 5 on the tower left to work ok.
there is no LTE even at 10km.
Gentlemen in Cambium, you passionately predicted that GPS sync is not working as it should.
Hi Fedor
Why is that?
You did it three years ago, then two years ago without results.
I no longer have the nerve or time for that, but I have the time and desire to be loud on the forum.
You still haven’t answered me if you know how to solve it or if you want to solve it.
It’s not just me who has the problem, everyone has it
except for those who do not use GPS sync so solve the problem globally.
Check that firmware once and pay attention to the signal margin. Even a blind person would see that, what is the problem with you.
Regards
I don’t think I personally did it 2 or 3 years ago.
And you are not providing me the support ticket number where I could check technical aspects of the issue.
Hey all, if you are having issues with the ePMP2000 radios please try running the latest firmware and the new pucks issued for the ePMP3000 series (the round ones).
So far we have had great success by doing this. I am working with Cambium to resolve this issue and it is something we have been testing for a few weeks now with success. To me it is still early in testing but so far every ePMP2000 we have put 4.6 firmware combined with these GPS pucks has resolved the loss issue…
If more people can confirm this we may get broader results and more confirmation… If you have a AP that is constantly doing this I encourage you to try it and monitor the outcome and report back to Cambium
This site exists for constructive discussion, for people who are willing to help work towards a solution. Your posts are not constructive, and you have said multiple times that you aren’t prepared to help find a solution.
You say that these problems were reported while you were in another company. Tell us (privately if you like) the name of that company, so that we can look up the ticket details.
It is constructive and how!
I’m not the only one who has complained and still complains about GPS, this can be seen from many posts from various topics that touch on GPS in one way or another.
It would be more constructive for Cambium to realize that there is a problem. That problem is not solved by reducing me or someone else to exchanging emails or phone conversations. That recipe failed.
You have to understand me why I am frustrated.
Cambium is very happy to admit when there are problems, for example:
It wouldn’t do us any good to sweep problems under the rug; if customers lose trust in us, we lose those customers. It’s in our benefit to be transparent. There is no conspiracy to hide anything.
But in a complex system, there can be any number of different problems which all appear to have the same user-visible effect. For example, in the post above, the underlying problem had nothing to do with GPS at all, but with a separate component in the radio that shared a bus with the GPS. So saying “GPS does not work” is absolutely not helpful.
When customers report a problem, ideally we would replicate that in our lab so that we can be sure we understand it. That replication often requires the unit diagnostics so that we can be sure we have the same configuration. Sometimes we can’t replicate it, in which case the diagnostics are the only way we can try to understand it. Without diagnostics, there is very little we can do.