CBRS - Upper or Lower frequency?

When selecting a 10MHz channel, I don’t see any way to specify to use a lower or upper channel.

So for example, if selecting a 20MHz chunk and selecting 3580, how does cnMaestro/AP determine if it’s going to use 3590 or 3570 for the other 10MHz chunk?

Specify the center frequency.

If you want 3580-3590, specify 3585x10. If you want 3570-3590, specify 3580x20.

OK… that may answer my question from the other post then… 3550 and 3560 are CPASed out at the moment… so if I requested 3580 and 30MHz, it couldn’t give me the full 3570.

No, I don’t think it has anything to do with CPAS.

If you specify 3580x30, it should ask the SAS for 4 multigrants:
and then use only half of the outer 2. cnMaestro is doing the correct thing based on what you asked for.

But what you are asking for is suboptimum, it means you need 40 MHz from the SAS of which you are only going to use 30 MHz. That increases the probability of not being able to get all 4 multigrants, or having one of them terminated, or getting your EIRP reduced to protect a PAL protection area.

Yes, I understand that… but the 3560 is CPASed out at the moment… so my lower 5MHz was terminated. I see what I’m doing wrong and it’s a combination of being late, bad day… and a bit flustered with cnMaestro having massive delays reflecting what’s going on and needing an AP up tomorrow.


cnMaestro can be slow to reflect device status changes, but not things like spectrum inquiry or grant status. It can take several minutes for all the SMs to request their grants and register, that can be frustrating.

But if your grant request requires 5 MHz at the top and bottom, likely you’re still doing something wrong.

And if you’re in an area where waiting overnight for CPAS applies, get used to it, this is your life going forward. Cambium does give some recommendations on timing to minimize the CPAS delay, I seem to remember it depends a bit on which SAS you are using.

I could be wrong, but I think you can request 10+10+10 to get your 30 MHz, and if the SAS only approves 0+10+10 temporarily, you can run with that and later you may automagically get your additional 10 MHz and the EIRP will be adjusted accordingly. That way you could be up and running now with a little less bandwidth than you’d like. Best to get someone from Cambium to talk more authoritatively about that, or check the operations guide and webinar video/slides.


That’s what I’m thinking – with the chunked grants… you could request a 10MHz channel to get up… and that will take place while waiting for the rest.