Could a 450M 3GHz support 3900 - 3980MHz?

I have read that, and have already been in discussion with several CanWISP members. Here is what we can say at this time.

The hardware does not support operation in that band today. We have component-based filtering in place to prevent out of band emissions, which includes things above 3900 or so. We can enable the product to operate in frequencies higher than 3900 MHz, but there is performance degradation that gets worse very quickly beyond that… we will work to characterize this, but I don’t expect those results to show that the product platform is practically usable from 3900-3980 MHz.

Cambium stands ready to support (with as much data as possible) the arguments that CanWISP intends to make, and my personal opinion is to try to quantify not only the cost of replacing existing equipment, but the lost opportunity cost of stopping all current investment for your business due to the possibility of being displaced by “Option 2”.

For those that want to read about the possible options, Section 9 of this document covers the potential outcomes.


Thanks Matt,

To all reading: If you are a user of 3.65 in Canada I highly urge you to submit comments to ISED to get away from 3900-3980. This would be an extreme problem on our network as it sounds like we would have to wait for a specific run of hardware from Cambium to run 3.90GHz. Doesn’t sound like the right move for Canada.

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Ryan, if you are not a member of CanWISP, I would recommend checking out the organization. We are the Canadian version of WISPA.

Our organization is definitely working hard on this consultation.


Hi Terry,

I am a member. Haven’t seen any discussion about this on the mailing list but glad to hear canwisp is also understanding how this would impact current WBS users.

Is there any chance that Cambium would do a hardware revision? It would be entirely for the Canadian market, so that begs the question whether Canadian customers are a large enough group for there to be a business case for such a thing…
All I can say is that I sure hope they are.

5 posts were split to a new topic: Any chance of 6GHz PMP450?

Final decision has been released: Decision on the Technical and Policy Framework for the 3650-4200 MHz Band and Changes to the Frequency Allocation of the 3500-3650 MHz Band - Spectrum management and telecommunications

What’s the official word from Cambium?

@CambiumMatt provided some information during the 2021 CanWISP presentation and has characterized the impact on existing PMP 450x equipment currently operating in the 3.3 - 3.9 GHz spectrum.

  • Works reasonably well up to 3940 MHz

  • 3940 - 3950 MHz, ~2-3 db loss

  • 3950 - 3965 MHz, ~3-4 dB loss

  • 3965 - 3980 MHz, ~6-8 dB loss

The Good News: 3 GHz 450m re-design will eliminate most of this loss - Due to release Q4 2021.



I am trying to determine the best path forward. Can you comment on the CPE. Can we expect to see the same loss of 6–8dB at 3965 - 3980 at the CPE if a current CPE is connected to the newly redesigned APs. If so, is there a new CPE planned for the Canadian market


@CambiumMatt (just bumping)

We are making progress on the 450m and are currently expecting a Q4 introduction. Most of the loss is due to the Rx chain on the 450m, and this will be eliminated with the new device. Using the current 450b SM, you’ll still see 2-3 dB total link budget loss. We are currently planning software calibration changes to help with this as much as possible, but no new SM hardware plans as yet… still evaluating the capability of launching this program in the future.

Is this a software redesign or new 450m hardware?

This is a hardware refresh.

That is good to know… I am looking at jumping into 450m 3GHz but if ISED ruling changes the spectrum then I will have wasted a lot of money.

How about the old 3.3-3-5 models of AP’s and CPE? What kind of spectrum range can they move around in before they have too much loss?


Any update on the release of the refreshed 450m?


I’m hoping for an update as well…

Bumping this. Thank you

Due to increased constraints and delays on components (which have gotten much worse recently), we are now looking at introduction of the redesigned 3 GHz 450m in Q1, likely at the end of February.


Thanks Matt, appreciate the update.