Antenna parameters and gain in EWC

[jmprats]

Some doubts about antenna gain and parameters in EWC. I can't understand why is so complicated: I have to check which antennas the AP are using (A, B, C, D) and the antenna gain in 0.5 dBi units. Cases:

1. I connect an AP C9115AXE with 4 antennas ANT2525DW (gain 4dBi at 5GHz and 2 dBi at 2.4 GHz). The controller by default only enables antenna A and B. I understand I have to check also C and D. Is that correct? Moreover I have to set antenna gain to 8 at 5 GHz and 4 at 2.4 GHz. Right?

2. AP C9115AXI. I have some with internal antennas with just Antenna A and B checked by default and other with Antenna A, B, C and D checked. I understand I have to check the 4 antennas in all, true?

Thanks

[Flavio Miranda]

@jmprats 

 You shoudn't change anything related to antenna selection or antenna gain. This should be automatic. Thats the WLC function

[jmprats]

thank you for your answer, but I am pretty sure that with AP's with external antennas you must configure the antenna gain. I am not as sure with the antennas selection (A, B, C, D) if I have to check them or not - I attach an image

[Flavio Miranda]

You dont. You can, but you dont. The WLC runs an algorithm that is able to handle this for you. That´s the whole idea of WLC in the first place.

 Changing Antenna gain will most probably give you problems. If you increate the antenna gain, it is worst if you dont know what you are doing, you are going to send the signal too far away or narrowing the access point cell to much or changing the antenna beam.  Keep it as default.

[jmprats]

I have viewed in another post https://community.cisco.com/t5/wireless/antenna-gain-configuration-non-sia-antenna/td-p/5195040

that can be important to set the antenna gain properly in order to not exceed the EIRP limits. Moreover my antennas are not SIA

[Rich R · Accepted solution]

Configuring the antenna presence and gain is essential for External Antenna models if they are not SIA (you are correct in that) because the AP cannot detect automatically but you cannot set gain on the internal antenna. The tick boxes simply allow you to DISABLE those antenna for that band (set separately for 2.4 GHz and 5 GHz).  I can't imagine any reason why you would want to disable antenna though.  By default both bands are enabled for all 4 antenna and I recommend leaving them that way.  Disabling antenna would just reduce the MIMO function of the AP.

Make sure your software is up to date - refer to TAC recommended link below.

[jmprats]

thank you very much