PMP450x Release 20.3.1 is now available

Cambium is officially releasing the PMP450x Radio 20.3.1 software.

Radio software and documentation can be found on the support site, and will be available on cnMaestro cloud within 24 hours.

Problems and Limitations corrected in System Release 20.3.1:

Since release 20.3:

Products Affected Tracking Description
3 GHz CBRS SM’s CPY-17601 CBRS EIRP recommendation from Federated Wireless SAS causing SM to go into relinquishment loop. Cambium put out an advisement email to operators using Federated Wireless SAS on 10/1 recommending against upgrading to anything later than 20.3 BETA-1 if using Federated Wireless SAS due to a customer found bug in Cambium software. This has been fixed in System Release 20.3.1.
3 GHz CBRS 450m AP/BHM’s CPY-17608 Improvement to suspension handling on PMP 450m when “Reboot for Channel Bandwidth Change" flag was disabled.
All AP/BHM PMP 450m products CPY-17060 Improvements to logging details for crashed/hung AP’s.
3 GHz CBRS 450m AP/BHM’s CPY-17618 Corrections to Cambium’s Tx Enable/Disable handling on manual bandwidth changes and deregistration scenarios.

Any news on AutoContention for the 450m?

I’m sure @Charlie can elaborate more on this… but from what I was told this feature will probably never come to 450m due to issues with how contention slots work with the MU-MIMO groupings, also, I was told that 450m in general doesn’t have nearly the same issues in regards to allocating upload slots, again, due to MU-MIMO. Basically, it causes performance issues with 450m, and 450m doesn’t really need it anyway due to how MU-MIMO intelligently treats upload traffic.

so should we just be pulling a number randomly for our 450m’s to stick with for contention since it’s less an issue?

No, you should read and follow Cambium’s recommended contention slots white paper. Set your contention slots on your 450m’s, and then set this number on all your 450/450i AP’s that you want to sync with that have auto contention enabled… e.g. we use a contention slot value of 6 on all of our 450m’s and then set this number on all of our 450/450i’s that have auto contention enabled.


Thanks for replying @Eric_Ozrelic ! I was going to make the same reference, but you beat me to it.

Although that paper is now almost 4 years old, the recommendations are still relevant.

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