Configuring antenna port parameters

[mlieber]

Hello, a customer has bought a new AP 3500 with external antennas and he would like use his old antenna

AIR-ANT2485P-R.

We have the option to configure the antenna parameter in WLC under

Wireless > Access Points > Radios > 802.11a/n or 802.11b/g/n for external antenna and and using only port A.

But if  we enable only one port (Example: port A) we will get a warning message: Need to have at least both dual mode antennas (antennas A and B) enabled

Is it not possible to use an antenna like ANT2485P-N together with an Access Point like 3502E?

thanks

Martin

[Stephen Rodriguez]

The 3500 doesn't use dual mode antenna, that would be a 3600/2600. So that could just be a cosmetic warning.

That being said you can use just one antenna but you will severely degrade the abilities of that AP. they would be better off purchasing the N rated patch

Steve

Sent from Cisco Technical Support iPhone App

[jonas · Accepted solution]

I now have the answer to disable B+C+D leaving only A antenna active on a Cisco 3600 and 3700 series AP.

Essentially what needs to be done is disable beamforming on the radios that you need to only have the A antenna enabled.

(Cisco Controller) >config 802.11b disable Serge-LAP-3700-1
(Cisco Controller) >config 802.11b beamforming ap Serge-LAP-3700-1 disable
(Cisco Controller) >config 802.11b 11nSupport antenna Serge-LAP-3700-1 B disable

Antennas must be disabled in D, C, B order.

(Cisco Controller) >config 802.11b 11nSupport antenna Serge-LAP-3700-1 D disable
(Cisco Controller) >config 802.11b 11nSupport antenna Serge-LAP-3700-1 C disable
(Cisco Controller) >config 802.11b 11nSupport antenna Serge-LAP-3700-1 B disable
(Cisco Controller) >config 802.11b enable Serge-LAP-3700-1

You will now see in the GUI that only Antenna A is marked.  Repeat the above process replacing '802.11b' with '802.11a' if you also need your A radio to only use the A antenna on the 3600 or 3700 dual mode ap.

Steve I am using this Access Point with Leaky Cable Antenna Technology and therefore it is essential for me to deactivate all the other antennas.

Best regards,

Jonas Nielsen

[Saravanan Lakshmanan]

AIR-ANT2485P-R is an supported antenna for 3500E AP, however it should be 6 dBi or less. And quantity require is 3.

*Not approved for use with Cisco Aironet 1260 Series, 3500e, and 3600e Series Access Point  (must be 6 dBi or less)

http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/at_a_glance_c45-513837.pdf

You could still use one antenna by disabling A & B or B & C radio ports, however you don't get true N stuff diversity, max speed, range....

[mlieber]

Hello Saravanan,

yes, you're right.

I know the dBi value was wrong configured by the client.

When we disable port B&C we will get the following error message

[Saravanan Lakshmanan]

what model wlc and code in question.

[mlieber]

WLC5508 and SW 7.3

[slilley]

I get the same results here with a 3602e AP and a 2504 WLC running 7.4.110.0.  If I try to select just antenna "A", it automatically keeps both "A" and "B" active.

Seems to work OK with just one antenna on the A port.  With just MCS 0-7 rates supported when using one antenna, the fastest speeds supported are 150Mbps w/ 40MHz channels, or 72Mbps with 20MHz channels.

Regards,

Steve

[jonas]

I get the same error " Need to have at least both dual mode antennas (antennas A and B) enabled" on a 5508 and a 2504 when selecting only the A radio on a AIR-CAP3602I-E-K9.

The 'funny' thing is if I select only the B or C or D radio the message reads "Invalid antenna combination selected. Valid combinations are A, A+B, A+B+C and A+B+C+D."

So the WLC is suggesting that an A only option is valid yet it will not actually accept it.

Is there some feature that needs enabling or disabling to configure only the A radio active?

I need to connect an antenna on this AP that only has one connector.

Cisco Please advise!

Best regards

Jonas Nielsen

[mlieber]

disable beamforming in CLI configuration

then it should work