Hello everyone,
Currently using a ubiquiti omni antenna paired with a ePMP 3000l radio. After many days of careful observation my radio seems to drop sessions at random moments. For example, I noticed that there was a session with 16-20 hours, others 15 minutes long and others with 5 minutes long. But none of them are stable. They drop for reasons unknown to me. Checked everything, from cables to the settings of the radio itself. Anyone have a recommendation or encountered the same problem and how did you fix it???
Omni Antenna (radio at this point does not matter) hears noise from 360 degrees, hears signals from 360 degrees.
so anything that can transmit a strong enough radio signal will be heard by this antenna regardles of the location of the interferer!
Now this is where the specific radio matters:
Your electrical down angle on your omni gives you a basic idea of your full strength coverage area, as you come closer to the tower the signal is reduced until at some point you can not get a signal that is usable. At this point it is critical to know several things A) your AP RX sensitivity, B) your antenna gain for this angle (see pattern chart), C) your TX antenna gain (SM your using to test with) and D) your TX power on the test SM. With this information you can calculate the maximum signal to failure that your system can tolerate before you have issues, this is not signal to noise ratio but another measure of how much you can tolerate before the AP can not hear an SM and keep its session alive. Once you know how much you can tolerate, you can select a frequency that has less than that amount of noise on it. Frequency selection is a very time consuming but important process, we are using shared spectrum and to top it off its shared with users whom just set it to max and call it good. Remember, out of the box a lot of wifi routers transmit on high when low or medium is all that needed. Channel bandwidth also effects how much you can tolerate. If your using 40Mhz channels but do not offer speeds that use the bandwidth, then there is a good reason to switch to 20 or 10Mhz channels. A 20Mhz channel will tolerate more interference than a 40Mhz channel, same for a 10Mhz channel. On a 40Mhz channel you need a signal of -70 to stay connected, but on a 20Mhz channel you only need a signal of -78. Yes max throughput is lower, but you can still punch a 50Mbps connection is your SNR is high enough, low to mid 30s is good.
With the 3000L, we found that is looses GPS if you have any co-band interference on the GPS, a puck does help but it isnt the all in one solution. Setting your hold-off time to something longer than default is a good idea, but it can also introduce drift in your transmit timing on a system that has overlapping towers, this feature is in seconds where 3600 = 1hr. Guard interval is another item to consider, try to match any with radio guard intervals, if most of the wifi in your area is using short, you use short. If most are using long, use long. Frame size will not matter against wifi interferers but make sure you use the same frame size across your entire network! Same with up/down ratios. This does not stop all drop outs as even the SM can fail to hear enough beacons to stay connected. Use cnMaestro mapping and plot all of the SM's on that tower by adding their actual geo-locations to the SM. This will help you visualize where the interference is coming from as it will show you which SM's are offline and which are not. This will help you determine if its self-interference from adjacent SM's or cross two or more towers because the SMs can hear other signals.
We are using Altelix Omni antennas in our low density areas where it does not make sense to place 4 sectors up.
Possibly a firmware issue vs what firmware the clients are using vs all AC clients or N clients or a mix. Also make sure the spectrum analyzer isn't on it causes all sorts of problems if you leave it running (at least up to 4.4.3, don't know about 4.5).
We have a 3000L / Omni micropop, mixed N / AC and 4.4.3 on everything. We had a lot of problems, including session drops, the AP dropping all N radios or dropping all AC radios, or just random drops. In the end 90% caused by the SA running and 10% resolved when we downgraded the AP to 4.4.1 and left the clients on 4.4.3.
Also, make sure all clients are running the same version of firmware, having just one client on a different version of firmware than the others seems to cause all kinds of problems with AP running 4.x
@brubble1 wrote:Possibly a firmware issue vs what firmware the clients are using vs all AC clients or N clients or a mix. Also make sure the spectrum analyzer isn't on it causes all sorts of problems if you leave it running (at least up to 4.4.3, don't know about 4.5).
Then why the h311 don't they put a frick'n display indicator on the frick'n top bar when it's running? I've asked and asked and asked and asked for that.
How is this difficult? When we go to the SA page, it (obviously) knows if it's ENABLED or DISABLED, and it (obviously) displays a radio button in the correct " ( ) Disabled (*) Enabled " location. SO - if they can display a 'radio button' in the GUI - they could display a SA icon in the GUI to bar, just like they do for the number of logged in users, for Internet Connectivity, for the GPS Status.
- SA_IN_THE_STATUS_BAR.jpg (15.1 KB)
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The SA causes so much chaos they should require 2 factor authentication to even turn it on and it then it should call you ever 5 minutes to remind you that you left it on...
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Exactly. I have suggested a timed SA a dozen times as well. If the SA is going to wreak havoc on everything, then when we start it, we should be able to select "5 minutes" or "15 minutes" or whatever. And have it run, collect its data, quit, and KEEP THE AGED INFO IT COLLECTED in the display.
And the root cause of 90% of that for us, is because the GUI since 3.5.6 insists on logging people out. The GUI itself, RIGHT ON THE LOGIN SCREEN (not buried several clicks deep) should ask the inactivity logout "disable / enable / time" question.
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