We have noticed that several of our CBRS SM's have randomly dropped from an EIRP of 46 to 41. The 46 EIRP is what has been Requested and Authorized when originally onboarded. The weird thing is that according to the CBRS Status List, we are now only asking for an EIRP of 41 and Authorized for a 41. I have double-checked my spreadsheets that have been uploaded and we are asking for a 46 EIRP in all cases. We have never asked for a 41 EIRP.
Please see attached screenshot.
The workaround has been to Relinquish the Grant and De-Register the SM from the AP and SAS. We can then load the SM back into SAS and start all over. 100% of the time we have Requested and been Authorized for a 46 EIRP.
Has anyone else seen this?
There is a chance the SAS could be reducing the EIRP. Do you see any alarm/event notifications in your cnMaestro account indicating this?
I really don't see anything to suggest that the SAS is dropping the power. With that being said, we are new to this so that most certainly could be the case.
In my case, I have yet to see a 450, 450i SM or AP reach the 46dB requested EIRP. All 150+ radios have come in at 41dB and get turned down further depending on their link quality. The 450b apparently has the ability to hit and EIRP of 48, and I have seen it authorized for as high as 50. I have not yet seen one actually transmit this high though. The only exception to this rule is the one 3GHz Medusa we have on our network that is getting to 48dB. In some ways, I wonder if it's due to the power available from the standard cambium POE/CMM5. Whereas the 3Ghz Medusa has its own dedicated power supply. Just a guess though
On the other hand, I have seen a handful of customer radios that originally only get authorized for 28dB. After some relinquishing and rebooting,they will finally come in at 41dB
Are these power levels affecting your ability to achieve the best modulation possible? I am curious if this limit is affecting your ability to provide the optimal service level.
There are certainly a few that it could allow the customer's upload to achieve better SNR's, but has them turned down slightly. Below is a good example. We have no competing noise that I am aware of, yet this customer is turned down rather than being allow to reach a level that could get him as much as 30dB SNR. Customer isn't complaining, but still... why?