Reply
Highlighted
New Member
Posts: 6
Registered: ‎09-12-2017

Low throughput / high ambient noise after turning off GPS Sync

I apologize if this isn't the right section.

 

We have 2 sectors on a tower using Rocket 2xc Prisms, 10Mhz channel widths. After 8.5.4 and 6.1.7 XM/XW moved off Beta, we upgraded all the clients and APs to use TDD Fixed Framing / GPS Sync as we have it on an omni elsewhere. Both sectors had clients suddenly start dropping, so we turned it off. Moving back to Flexible Framing, no GPS sync, the ambient noise shown on one of the AP's dashboard went red (-39 to -45, high -70s to low -90s prior). Further two clients, a Nanobridge and a Bullet/grid got locked into low RX rates, 7.222Mbps and 3.xMbps. Only an AP reboot cleared those, client reboots changed nothing. Aside from the ambient noise increase and that situation, everything did and does look normal with the AP and clients.

 

Speeds, however, are 2x-3x slower than before the upgrading and turning off GPS sync with regularity. Before the upgrade, dual-polarity radios would see 15-25Mbps running iperf from our office, now we're seeing 3Mbps-8Mbps mostly running those same tests. Speed tests on the other sector are normal. We run the same tests from the same server, so even if the speeds aren't fully accurate, we use the consistency as the gauge.

 

I've played with about every setting combination there is available, eventually downgrading all the clients and the AP (back to 8.51, 6.1.6), multiple reboots, I cannot get the speeds back to where they were or at least consistent at a higher level,  nor can I get the ambient noise indicator to stay out of the -40s. It was never to that level that I saw before upgrading to 8.5.4 and turning off Fixed Framing.

 

I rebooted the AP again this morning and ambient noise went from -41 to around -90, and the speeds look close to normal after the reboot. However, I have no idea how long it'll stay this way, and I've been dealing with this for about 2 weeks.

 

Presently have this set as Data Rate Module: Default, Wireless Network Protection: On, TDMA Filter 0, AMPDU 24, AMSDU Off.

 

Any insight or help would be appreciated.

 

Thanks.

 

rocket2ac.png
Ubiquiti Employee
Posts: 7,676
Registered: ‎04-14-2017
Kudos: 1494
Solutions: 212

Re: Low throughput / high ambient noise after turning off GPS Sync

I suspect what you are seeing is heavy self-interference between your APs, which GPS Sync was preventing. Can you give me some more details on what was happening when you had GPS Sync enabled?
New Member
Posts: 6
Registered: ‎09-12-2017

Re: Low throughput / high ambient noise after turning off GPS Sync

TX/RX on some clients was unstable compared to normal, and some of them would either disappear from the AP for a while, or were connected but unreachable until we kicked them or there was a reboot in some cases. 

 

I don't know if it mattered or it's how it works, but the reported distance was off 1 or more miles beyond our furthest links, we tried by reverting AP settings and setting a fixed distance on the AP and auto distance, then re-enabling, and it didn't matter. 

 

One side had trouble around a gravel pit with GPS sync on, the other side had trouble mostly around a line of houses that have had a history of noise problems. This is the AP that is giving us trouble. 

 

We didn't have this issue when everything on that tower was at 8.5.1 and 6.1.6, and they were all upgraded at the same time. GPS Sync was left on for most of a work day, ambient noise became red on one AP after turning it off, and speed complaints started coming in the next day. We've been out to the area twice to scan from the ground, and nothing new is showing up from the AP in a scan, either. In case something new was turned on the day of the update.

 

Sometimes when I reboot the AP the noise level drops considerably, but so far it returns to -40s level.  It does appear to improve on its own, but I can't see a pattern yet.  I've tried syncing and separating sector frequencies, though we hadn't moved them much since we put them in on separate frequencies.  I've run tests while rebooting client radios, the other sector, other 2.4Ghz APs,  there is no pattern to indicate it's a specific device causing the issue, at least that we control. 

 

Any recommendations would be appreciated. I'll suggest a factory reset to the business owner or maybe swap the radio, see if it behaves differently. 

 

 

 

 

 

Ubiquiti Employee
Posts: 7,676
Registered: ‎04-14-2017
Kudos: 1494
Solutions: 212

Re: Low throughput / high ambient noise after turning off GPS Sync

We should be able to figure this out and get it resolved for you. Can you show me a diagram of how these sectors are set up?
Reply