PMP450i AP vs PMP450 MicroPoP AP with License Key - Differences?

What are the functional differences between the PMP450i 5GHz connectorized AP and the PMP450 MicroPoP 5GHz connectorized AP with license key?

I recognize the MicroPoP version is limited in range and subscribers without the license key, but are there any differences once the license key is applied?

Thank you, Chris

Hello @uberdome ,

note this:

The PMP 450i Access Point 5 GHz connectorized would have option to add 90/120 degrees antenna and has all powerful feature of the PMP 450i access points radios.

The PMP 450i MicroPop is a new radio with a new design.

Cambium Networks should give more information on its hardware capabilities.

Note that the MicroPop Access Point are usually deployed for short and narrow coverage. The main difference may reside in the long range capabilities.

But, on the PMP 450i, the gain are greater on the sector antenna, viewed from LINKPlanner:

The range between the two Access Point models will differ.

Cambium Networks can advise more.

Sincerely yours,

Niragira Olympe

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@Olympe, I was specifically comparing the connectorized version of the MicroPoP radio since it could also be connected to the same antenna as a PMP450i. The specifications show that with the license key, there is no range limitation.

However, the specification sheet does show a different max power level:

PMP450 MicroPoP:
+27 dBm (MIMO, combined V+H) (+22 dBm @ 256QAM)

PMP450i AP:
+28 dBm (MIMO, Combined H+V)

The PMP450i AP data sheet does not indicate what power level is possible at 256QAM. Both of the maximum power levels are still going to exceed FCC limitations, so this should not affect performance when comparing the two.

Hello @uberdome ,

I get your point. Though, if the TX powers are similar and the antenna gain are different, the coverage range might different too.

Would you be patient and wait for Cambium Networks updates on this?

Sincerely yours,

NIRAGIRA Olympe

You can use the Link Capacity Planner tool, found here:

https://support.cambiumnetworks.com/files/capacityplanner/

This tool will allow you to accurately (but easily) see the range and modulation levels. You can change the equipment being used and see any differences.

@CambiumMatt what are the differences between the two? Are they functional equivalent? Does the MicroPoP version have the same filtering as the 450i? Are there any limitations of the MicroPoP or improvements in it that wouldn’t be revealed in the calculator?

I’ll go ahead and use the capacity planner spreadsheet to compare, but I’m looking for other information as well that would not be revealed there.

Regarding the Capacity Planner in this particular example, I’m seeing potential issues that make me question the results. For example:

  • The PMP450i is rated up to 28 dBm, but the planner only lets it go up to 27 dBm.
  • DL link budget appears to be calculated differently between the two (All specs the same, DL link budget at 1x on the 450i is 3 dB higher than on the 450u even though they have the same sensitivity and same Tx parameters)
  • If I max out power on PMP450u at 27 dBm, the link budget calculates using 22 dBm at 8x (As expected according to the datasheet); however, if I set power to 20 dBm which is below the 22 dBm max for 8x, it calculates using 15 dBm Tx power.

These issues beg questions like, is there a fundamental difference in how the 450i and 450u transmit 1x, or is there a calculation issue? When limiting power on the 450u, are you reducing the power used for every modulation evenly whereas in the 450i you are not? Is the max power on the datasheet listed incorrectly for the 450i, or is it incorrect in the planner?

Thank you for your help, Chris

The differences you are seeing are likely due to regulatory considerations.

In certain regions, there are specific out of band emissions that are required to be met. The product is capable of 28 dBm, but in the US, for example, it only allows up to 27 dBm, due to out of band emission limits. This same reasoning can be applied for the other scenarios you list. These power limitations are also affected by the proximity of the center channel to the band edge, so try adjusting the operating frequency and see if things change.

Fundamentally, the products operate similarly, but there will be some nuance because the regulations are constantly changing, so things may differ depending on when they were certified. The only other difference is that the 450 MicroPoP does not contain the dynamic interference filtering circuit that is present in the 450i. This does not, in itself, affect the link budget, but might help if the AP is deployed in high-noise environments (which is not typical when using a MicroPoP, which is generally used somewhere other than the Macro or Tower site).

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I turned Region to “Others” for testing the maximums since both exceed the US limits. I tried a few frequencies and it does not go higher than 27 dBm for the 450i. I admit I did not check every possible option.

Is the dynamic interference circuit the only thing the 450u is lacking?

The nature of the reduced link budget in 8x does not look to be regulatory. It could be a design limitation, I suppose. Since the other questions don’t have direct answers, I will open a support ticket to ask.

Thank you for the help. If you have any other differences to suggest, I’d be interested to see them.

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Hello Mr. @CambiumMatt ,

thank for the precision.
I am also learning.

Sincerely yours,

Niragira Olympe