NWA210AX lower transmit power on 5GHz compared to NWA90AX

malakudi
malakudi Posts: 12
First Comment Friend Collector
I really don't understand why my NWA210AX shows transmit power of 16 dBm on lower 5GHz channels (36 to 64) when NWA90AX shows 23 dBm on the same channels on same place with same regulations applied and same channel width (80MHz). Can you explain the difference?
When switching to channels of higher band (100 to 140), NWA210AX goes to 22 dBm (+6 dBm from lower band) while NWA90AX goes to 26 dBm (+3 dBm from lower band). This difference does not make sense. 
Even if I add the antenna gain where NWA210AX is 6dBi and NWA90AX is 4dBi, there is still difference:
NWA210AX 16+6=22 on lower band, 22+6=28 on higher band
NWA90AX 23+4=27 on lower band, 26+4=30 on higher band

Changing channel width to 40 or 20 MHz does not make a difference.

I bought NWA210AX for better, please explain why I can't get same dBm as NWA90AX.


All Replies

  • malakudi
    malakudi Posts: 12
    First Comment Friend Collector
    I attach screenshots where the different transmit power is shown in Nebula interface

  • Zyxel_HsinBo
    Zyxel_HsinBo Posts: 122
    5 Answers First Comment Friend Collector
     Ally Member
    edited November 24

    NWA210AX equip with 4x4 antenna, which provides more 3dBm power than 2x2 device (NWA90AX). Thus the real output transmit power need to plus 3dBm in your calculation.

    The transmit power is related to the channel and the channel width,
    When you use the same channel, the lowest channel width (20MHz) will be the max transmit power.
    Since factory chipset limitation that the power value of small business models (NWA50AX, NWA90AX, NWA55AXE) from Nebula front-end would always display the result of configuring with 20Mhz, and the power vlaue of NWA210AX will display the value according to the currently applied setup. ( NWA210AX equipped with different chipset )
    Thus it's the reason why the value of NWA21AX very different with NWA90AX in your test scneario (80MHz).
    Thank you.

  • malakudi
    malakudi Posts: 12
    First Comment Friend Collector

    NWA210AX equip with 4x4 antenna, which provides more 3dBm power than 2x2 device (NWA90AX). Thus the real output transmit power need to plus 3dBm in your calculation.

    The transmit power is related to the channel and the channel width,
    When you use the same channel, the lowest channel width (20MHz) will be the max transmit power.
    Since factory chipset limitation that the power value of small business models (NWA50AX, NWA90AX, NWA55AXE) from Nebula front-end would always display the result of configuring with 20Mhz, and the power vlaue of NWA210AX will display the value according to the currently applied setup. ( NWA210AX equipped with different chipset )
    Thus it's the reason why the value of NWA21AX very different with NWA90AX in your test scneario (80MHz).
    Thank you.

    Specifications in Zyxel site give for NWA90AX: 
    Antenna gain 2.4GHz: 3 dBi
    5GHz: 4 dBi
    And for NWA210AX:
    Antenna gain 2.4GHz: Peak Gain 5dBi
    5GHz: Peak Gain 6dBi

    So the difference is 2 dBi as I already mentioned and not 3 dBi.

    Also, what you say is not true, at least is not shown in Nebula interface. Even if I configure NWA210AX for 20MHz, it still shows 16 dBm for lower 5GHz band and 22 dBm for higher 5GHz band.
    Here is the screenshot:

    The thing is that I feel the transmit power is indeed lower, I placed both NWA210AX and NWA90AX close to each other and I see difference in reception, especially on lower band of 5GHz - but of course this is only a feeling since I don't have a spectrum meter to do accurate measurements. According to Nebula information shown, NWA210AX transmits 28 dBm on higher 5GHz band (22+6) while NWA90AX transmits 30 dBm on higher 5GHz band (26+4). And NWA210AX transmits only 22 dBm on lower 5GHz band (16+6) while NWA90AX transmits 27 dBm on lower 5GHz band (23+4).
    Since the limit for lower band of 5GHz for EU is 23 dBm with TPC, NWA210AX stands 1 dBm lower and NWA90AX 4 dBm higher.
    If NWA90AX displays transmit power with the value of antenna gain included while NWA210AX displays transmit power with the value of antenna gain not included, then NWA90AX is correct on lower band of 5GHz (23 dBm) while NWA210AX is 1 dBm lower (16+6=22 dbM). On the other hand, on higher band of 5GHz NWA210AX is 2 dB less from 30 dBm (22+6=28 dBm) and NWA90AX is 4 dB less from 30 dBm (26 dBm).
    It is completely confusing, since the antenna is not detachable or replaceable, Nebula should show transmit power with antenna gain included for both devices. And they should have same numbers on same config.

  • malakudi
    malakudi Posts: 12
    First Comment Friend Collector
    edited November 25
    And just want to add that on 2.4 GHz, NWA90AX reports 19 dBm while NWA210AX reports 20 dBm, with the allowed EIRP to be 20 dBm. So why we see 20 dBm for NWA210AX, for 2.4 GHz the antenna gain is included or not?

    And I want to mention that adding gain of antenna to the EIRP is actually incorrect method, since the energy is the same, the antenna just controls the directionality of the energy. Antenna does not produce energy.

    I would expect to see 20 dBm for 2.4 GHz (which I see on NWA210AX, but 19 only on NWA90AX), 23 dBm for lower band of 5 GHz (which I see for NWA90AX but not for NWA210AX, which I only see 16 dBm) and 30 dBm for higher band of 5 GHz (which I don't see on any of the two devices, 22 dBm for NWA210AX and 26 dBm for NWA90AX)
  • malakudi
    malakudi Posts: 12
    First Comment Friend Collector
    Can anyone from Zyxel reply to this?

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