Controllers and Displayed Antenna Types

mmatulevich · ‎07-11-2007

Our site's access points are a majority of 1242APs with some 1230s. They all are using external diversity antennas. Noticed that the controllers list under the details of all a/b/g radios as having 0 x 0.5dmb gain.

WCS shows the same gain value, and also shows 4941 (rubber-duck) models for the 802.11b/g types, and 5135d-r models for the 802.11a types.

Selecting the proper models that are actually in place - 2010's and 5170's, the gain is increased. One b/g radio I tested this on now shows 12 x 0.5dmb = 6dmb current gain.

I was pretty sure a higher gain with directional antenna's is a good thing, but not sure in the world of lwapp and auto-rf. I guess the controllers may be showing those other models as default because they have no gain to begin with? Just want to get some input before I consider correcting the values at my sites. Thanks in advance

aghaznavi · ‎07-18-2007

You are rite that a directional antenna provides higher gain traversing greatest distance. But the coverage will be very less.

Whereas, an omni-directional antenna's coverage will be more but the distance or range it traverses will be comparatively less. This should also be applicate Lightweight AP and controllers.

Refer http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a00807f34d3.shtml for more information on antennas.

mmatulevich · ‎07-19-2007

Thanks for the update! TAC explained to me that the specific model antenna type is not used in auto-rf calculations and only comes into play when plotting them on maps for heat signature accuracy?