Cambium PmP 450 3.65GHz issues

We have had 3 different 450 series 3.65GHz AP's on different towers since the product was released.  One of them has continually had issues since it was put on it's tower with LBT events from no where.  We have tried different firmware, different frequencies, different channel width, increasing/decreasing the power levels, increasing/decreasing antenna gain, turning on adjacent support, and turning off other Access Points around it.  Nothing has helped, and the problem has only gotten worse.  The other two AP's are 5 and 10 miles from the first and have never had a problem.

As if 1200+ LBT events wasn't enough, now we are getting errors that I can not find documentation on.  Can anyone please explain what a Bad Achnowledgement is under the Scheduler tab?

Bad Acknowledgment :

This number doesn't seem to be increasing at the same rate as the LBT events, but I am down to digging for any answers I can get.  If nothing else, I am at the point of scrapping the product alltogether.

Thanks in advance for any help


Hi Mike,

I would request you to please send us the CNUT capture of the AP and email us at We would open up a ticket and analyze the files.


Vivek Gupta