Canada 5.1 GHz band error

In Canada, the 5.1 GHz band has similar rules as 5.8

Specifically, for PtP systems, the max EIRP should be 53 (see

However, when I use LinkPlanner to plan a 5.1 Ghz link (PMP450m), the subscriber (450i) should count as a PtP link, correct? However, LinkPlanner shows the EIRP limit as 30.

I haven't used these in the wild either, I would be curious to know if the same limit applies to an actual 450i subscriber radio

Thank you for bringing this to our attention!

LINKPlanner and Cambium Networks products comply with the guidance for Canada, which is a combination of maximum conducted power, maximum antenna gain, maximum power spectral density, vertical elevation mask, and maximum out-of-band emission for outdoor, indoor, and point-to-point systems.

In this case, it’s not just a matter of ensuring that the PMP 450i SM’s EIRP is less than or equal to 53 dBm. (The combination of other factors above must be considered as well.)

I hope this helps!


So I’m confused. What is the maximum EIRP for a 450i SM in the 5.1GHz band in Canada? The regulation says 53 for a PtP radio, are you saying there is some other factor that is limiting the SM to 30 EIRP?

If so, what factor is that?

The out-of-band emission requirement ("-27 dBm/MHz e.i.r.p") is limiting the SM's transmit power.

I apologize for any confusion!


I really don't think that is the case. For instance, if I create a PTP450i link in Link Planner, it shows the max EIRP at 30 dBm (7 dBm max transmit power).

But I have an actual PTP450i, when I put it in 5.1 GHz, the max transmit power is 27 dBm. I don't have a PMP450i SM to test, but I would be curious if the actual hardware is limited to 7 dBm or 27 dBm transmit power

The same goes for a PTP670 by the way. LinkPlanner lists the max EIRP at 30, but I have an actual PTP670 on the 5.1 band, and it seems to operate at a maximum of 41 EIRP

Can you please confirm the antenna you are using (and have configured in the radio) and the bandwidth for the PTP 670? The max EIRP is dependent on both of these parameters and in LINKPlanner there are two options United States and United States (Parabolic) for when you are using an external parabolic dish.



The PTP670 has an integrated antenna, I think I figued out the PTP670 though, even though the radio lists 18 dBm as the max transmit power, the radio never goes higher than 13 dBm (which would be 36 dBm EIRP), this is on a 20 MHz channel.

LinkPlanner still seems a bit off, because it lists 30 dBm EIRP as the max for a PTP670 at 20 MHz, but it appears teh real world max is 36 dBm.

I don't have a PTP450i or PMP450i SM to test, but I'd be curious what the actual real world maximums are vs what LinkPlanner shows

I've attached a screenshot from a PTP450i, it shows (I believe) the radio transmitting at 27 dBm power on the 5.1 GHz band

When I configure LINKPlanner for 5.1 GHz United States, 20 MHz bandwidth with integrated antenna then it is also predicting a max EIRP of 36 dBm in agreement with what you are seeing in the product.

I'm using a 40 MHz channel on a PTP670 and it allows the EIRP to go up to 36

Maybe I need some consulting help from Cambium? Another question I have is about the 450b subscriber. The User Guide seems to suggest that the 450b subscriber can transmit at max power in the 5.1 GHz band, unlike the 450i subscriber, however LinkPlanner shows the maximum EIRP as 31 for a 450b subscriber

Additionally, in the 5.8 band, the User Guide shows a maximum power limt of 21 dBm and EIRP limit of 36

However this doesn't even make sense, if the power is 21, and the antenna gain is 23, the EIRP is 44. LinkPlanner shows 44 as the EIRP limit for a 450b in 5.8. Which numbers do I believe?

Regulatory can be quite tricky and involved, as you are seeing.

I suggest a quick call to customer support (or your Regional Technical Manager).

Be sure to mention this post.