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New Member

Question about 1252 Antennas

I would like to add an additional antenna to a 1252 LAP but I'm unsure of a few things...

I know this LAP currently has atleast a yagi directional antenna (AIR-ANT2410Y-R) and also a (

AIR-ANT2485P-R) connected to it. The access point is in a ceiling so I cannot view the connections but according to this data sheet, http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/at_a_glance_c45-513837.pdf each of the antennas I've specified require 3 per AP. I am only aware of 1 of each being used so not sure why 3 would be required?

Also on my 1252 1 side has 3, 2.4Ghz connections for antennas, TX, TX&RX, and RX. If I want to only use 1

AIR-ANT2410Y-R, would this be connected to the TX&RX port? Do all antennas support tranmit and receive or are there some that only support TX and others that only support RX or is this based only how you configure the antennas? On the other side of the access point there are 3, 5Ghz antenna connections.

TIA for the help!

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Gold

Re: Question about 1252 Antennas

The yagi directional antenna is being used in a concrete hallway with steel doors, The other flat directional antenna is being used in a different hallway. What I'd like to do is add a 3rd antenna for the 3rd hallway.

The antennas for the WAPs are NOT designed as a "distributed" antenna system.  It's designed for DIVERSITY.

Is it possible to replace the 5Ghz slot with a 2.4Ghz slot like the other side?

Bad idea and it won't work.  Bad idea because you just cut down your allowed channel from three to two.

Also do all new 1252 APs come with 5Ghz and 2.4Ghz cards or is it possible to order them with 2, 2.4Ghz cards?

All 1252 come with one 2.4Ghz radio module and another 5.0Ghz radio module.  You won't find a 1252 with TWO radio modules of the same band.

7 REPLIES
Hall of Fame Super Silver

Re: Question about 1252 Antennas

The outer antenna ports are TX/RX the middle is RX. For indoor use, it's best to use all three on each radio. However, you need to use the correct antenna. The dipole antenna should have three, if you have a yagi, that's really for outdoor use in my opinion. Don't try to use a high gain antenna to increase coverage as that is a bad idea. Stick to what best, use antennas made for the access point. So it's either the omni dipole or antennas that have three leads which can be an omni or a patch antenna there are 6 lead antennas that are omni also.

Sent from Cisco Technical Support iPhone App

-Scott
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Question about 1252 Antennas

There must be at least one Rx/Tx antenna connected for the AP to work.
For the AP to work better you may need 3 antennas for hte radio. Howeber, if you for some reason want one antenna to be used you must connect it to the Rx/Tx port. Otherwise the AP won't work fine.

HTH

Amjad

Rating useful replies is more useful than saying "Thank you"
New Member

Question about 1252 Antennas

Thank you for the replies! Scott, you're right both outer ports are TX/RX and only RX in the center (this makes more sense than what I originally thought). The yagi directional antenna is being used in a concrete hallway with steel doors, The other flat directional antenna is being used in a different hallway. What I'd like to do is add a 3rd antenna for the 3rd hallway.

So I guess I will have to check the AP to see what's actually being used. If they're both 2.4 then would that mean I'd need another AP in order to have a 3rd antenna? The other 3 connections are for 5Ghz and my clients will not support that. Is it possible to replace the 5Ghz slot with a 2.4Ghz slot like the other side? This would enable me to have up to 4 TX/RX antennas for the 1 AP, correct?

Also do all new 1252 APs come with 5Ghz and 2.4Ghz cards or is it possible to order them with 2, 2.4Ghz cards?

Do all antennas support TX/RX?

Hall of Fame Super Gold

Re: Question about 1252 Antennas

The yagi directional antenna is being used in a concrete hallway with steel doors, The other flat directional antenna is being used in a different hallway. What I'd like to do is add a 3rd antenna for the 3rd hallway.

The antennas for the WAPs are NOT designed as a "distributed" antenna system.  It's designed for DIVERSITY.

Is it possible to replace the 5Ghz slot with a 2.4Ghz slot like the other side?

Bad idea and it won't work.  Bad idea because you just cut down your allowed channel from three to two.

Also do all new 1252 APs come with 5Ghz and 2.4Ghz cards or is it possible to order them with 2, 2.4Ghz cards?

All 1252 come with one 2.4Ghz radio module and another 5.0Ghz radio module.  You won't find a 1252 with TWO radio modules of the same band.

New Member

Question about 1252 Antennas

Thanks for the info leolaohoo, where would you normally find this type of information? I have Cisco's CCNA Wireless book and a brand new 1252 and did not find any documentation.

The 1252 Ap that has the 2 antenna's in different location is supporting around 20 users. The hallway for the third antenna I wanted to install would only support 2 or 3 users. Is there a smaller AP that exists to support 3 users and still be compatible with my WLC and WCS enviornment? Also does a distributed antenna LAP exist?

Hall of Fame Super Gold

Question about 1252 Antennas

Also does a distributed antenna LAP exist?

I've seen the phrase "distributed antenna systems" (DAS) being mentioned around but I've never used it.  Cisco does not support this either.

The 1252 Ap that has the 2 antenna's in different location is supporting around 20 users. The hallway for the third antenna I wanted to install would only support 2 or 3 users. Is there a smaller AP that exists to support 3 users and still be compatible with my WLC and WCS enviornment?

Hard to determine and hard to give you an answer.  There are alot of factors which determines whether or not a single WAP can cover that much distance or radius.

One of them is potential channel interferance, location of the WAP, walls, any metallic structures (filing cabinets, compactors, elevator shaft) between the WAP and the client(s).

My opinion is to get another set of WAP.  If funding is an issue, and 802.11 a/b/g (no 802.11n) is a minimum then look at the 1130. This model is very, very affordable.

Question about 1252 Antennas

Mark,

The 1252 is a 2x3 Multiple In/Multiple Out radio with 2 spatial streams.  That means that the data stream the is being sent to the client is being split between the two transmitter/antenna combinations (802.11n).  In single stream mode, the 2 antennas are used in spatial diversity and transmits on the antenna with the best receive signal from a specific client.

It is hoped that all clients can actually hear each other because in the radio scheme of things, only one device can transmit at a time (a very tiny chunk of time).  If two or more talk at the same time the signal is scrambled.  Your design has created a whole group of hidden nodes,  the devices down each hallway that continually step on each other.  Even if the AP is hung in the junction of the hallways and had all three antennas operating omni style the hidden nodes would still exist.

Yes the best bet is an AP in the middle of the lenght of each hallway.

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