So after upgrading to 15.1.1 I now have 6 access points that kick DFS errors regardless of what channel I try, even if the spectrum analyzer says its clean. All of theses ap have been up and running for months having never kicked a DFS error until the moment I installed 15.1.1 Any ideas? At this point I may just have to go back to 15.0.3. I don’t have the room to put them all in 5.7.
What model AP are these?
Are they PMP 450 or PMP 450i?
Are you near a TDWS or no?
There have been changes in the rules surrounding DFS event detection that we were forced to put into the radio software, but we are doing our best to meet the regulations while limiting the amount of "false" detections.
There may be something we can further improve here.
Where can we see the rules.
I'm running vanilla PMP450 APs & SMs.
I know you are working within the FCC mandates, but...
I would like to know what the protocol is once a detection kicks off. Do you listen for x amount of time to make sure the channel is clear (False detection). Is it a set 30 minutes then up? What I have started doing is to reboot the AP once the sector goes down. It hasn't failed to restart yet. If it is an actual detection, why is there no data in the log?
07/18/2017 : 07:22:42 CDT : :type 00000000, width 0, period 00000000, mult 0, cnt 0
The rules are a subsection of the FCC Part 15 rules... and the updated rules can be seen at this link.
In a nutshell, as soon as there is a detection, the radio will move to the alternate channel (if configured) and must remain out of the detected channel for 30 minutes (it checks every minute to see if the energy or radar signature is no longer there).
1 Like
Theses are all pmp 450m. There is radar near by at the airport, there always has been, never a problem until now. Two of these ap have been running 5.4 for over two years without a single hit. They where the original 450 before we switched them to 450m about 4 months ago. As of now we are going to have to go back to the stable 15.0.3 since we don't have room for everything in 5.7
@CambiumMatt wrote:The rules are a subsection of the FCC Part 15 rules... and the updated rules can be seen at this link.
In a nutshell, as soon as there is a detection, the radio will move to the alternate channel (if configured) and must remain out of the detected channel for 30 minutes (it checks every minute to see if the energy or radar signature is no longer there).
Is there a way to "see" the data the unit is aquiring during these one minute checks. Does the detection last a minute, ten etc. Something like Radar detect - No Radar Detect - End Radar Detect. Again, why no data in the log? Just a bunch of 0s.
We don't have any alternate freqs available.
I'd like to know for sure, or as close to sure as possible, whether or not the detection is real. What, if anything other than radar, can trigger the detection? Solar flares, Global Warming/Climate Change? (TIC)
I wouldn't think a detection that doesn't last 10 minutes, let alone 1, is real, but what do I know.
Just had a lightbulb moment -
Will police radar cause a detection? We not only have a station within .5 miles of the tower, but a police officer lives across the street from one of our subs. Will an SM detection cause a sector shutdown?
Thanks for all the info on this matter.
Does the antenna you are using match the gain setting in the gui?
last week I upgraded our towers to 15.1.1 and we instantly started seeing a lot of DFS hits on three of our busiest towers. we are nowhere near any TWDR (closest is Denver and it's 100+ miles away over two mountain ranges). I downgraded the APs to 15.0.2 last friday and all three towers have not had a single hit all weekend.
it's been happening on some of our smaller towers too but to a lesser extent. The APs that are seeing DFS hits the most are the origional 1st generation 450.
Are there any recommendations to try to limit the false DFS events detected on firmware 15.1.1 and above? I have tested the latest official build for PMP-450/450i (15.1.5) and it does not seem to improve the amount of detections. We are seeing this issue on PMP-450/450i and PTP-450i radios across multiple states of the country. I created a ticket with Global Customer Support more than two weeks ago in regards to this problem but they appear to be completely unaware of this issue.
We have been able to downgrade the firmware to an earlier version as a temporary solution in some instances. However, that is not always possible as we constantly buy and deploy new equipment that is already pre-configured with firmware 15.1.1 or above. Please advise.
1 Like