cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1575
Views
0
Helpful
5
Replies
Willem de Groot
Beginner

Question about Antenna settings on 1852E in Mobility express

Hi all,

I'm not sure about the settings of the"Antenna Configuration" for an 1852E Mobility Express Access Point.

2019-09-13_15-08-14.jpg

 

If I look at the datasheet for the 1852E, it notes that 2.4GHz uses 3 antennas. -> Does that mean that for Radio 1 only 3 Antennas need to be ticked (which 3)?

The antennas I use are AIR-ANT2524DW-R-RF 2.4GHz2 dBi/5 GHz4 dBi DipoleAnt.White,RP-TNC

so, is it correct that I have to change the Antenna Gain for 2.4GHz to 4 x 0.5 dBi?

 

Thanks a lot

Willem

5 REPLIES 5
pieterh
VIP Collaborator

>>> Does that mean that for Radio 1 only 3 Antennas need to be ticked <<<

-> NO. the 4th is also used, it means only max. 3 antenna's are used to transmit, this could vary according to client position.

if 4 antenna's are mounted -> all boxes ticked

 

the current shown  antenna gain settings are correct

   2,4GHz: 2dBi -> 4x0.5dBi

   5GHz: 4dBi -> 8x0.5dBi

pieterh

 

I have 2 x 1562E AP's. One is the RootAP and the other is MeshAP mode to create a bridge. Each uses a single AIR-ANT5114P2M-N external antenna which have 14 dbi gain. Using your info below.

 

2.4GHz: 2dBi -> 4x0.5dBi

5GHz: 4dBi -> 8x0.5dBi

 

My setting should be 

5 Ghz: 14dBi -> 28 x 0.5 dBi ?

and according to Cisco's documentation. the antenna is actually 13 dBi gain with cabling.

Would I be right on this?

No not really,
when I wrote 2,4GHz: 2dBi -> 4x0.5dBi
this meant using 4 internal radio's each at power level 0.5dBi

28 X 0,5 dBi would describe 28 radio-transmitters in above calculation

 

but i believe the AIR-ANT5114P2M-N only has a single coax-connector?

so you can only attach and use a single radio from the AP and disable the others!

 

furthermore dB's are not multiplied but added/substracted

-> the 14dBi of the antenna should be ADDED to the dBi's of the radio.to calculate ERP.

or other way around: ERP - Antenna-gain = radio-power

Hi Pieterh,

 

Okay so that's asking for the radio count. its calculating the Antenna Gain =  (# radios) x 0.5 dBi

 

Sorry for my ignorance. This is quite a confusing parameter in the WLC as I have looked all over documentation and states very little about how to calculate and that its the radio count. I am only using this as a bridge. they are not taking clients. The AIR-ANT5114P2M-N has two antennas with 2 connector pig tails. Right now, I'm only using the 802.11a side for the backhaul on the bridge.

What should I be using for the radio count? 2?

The radio count available depends on the electronics circuit in the access point. you do not need to calculate the number?

the 1850 series has a total of 4 connectors each internally connected to a dual-band radio

so 4x 2.4GHz radio's and 4x 5GHz radio's present

as you mention the  AIR-ANT5114P2M-N has internally two antennas with total 2 connectors you can only connect two of those radio's to the antenna.the other two connectors on the AP are unused.

also as the antenna is only 5GHz (not dual-band ) you need to disable 2.4GHz

I also advise to disable the unused 5GHz radios in the AP configuration.

never done this on a 1852, but I guess you do this by disabling diversity and then select the active antenna's

 

 

 

 

Create
Recognize Your Peers
Content for Community-Ad