Best Antenna Choices

Configuring Wireless Cisco Networks and Wireless Controllers.
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Best Antenna Choices

Post by Guest » Fri May 29, 2009 1:00 am

Im up the creek the content filter here won let me mention. Ive an Aironet AIR-AP1252AG-A-K9 and a smallish three-story, 9-unit, wood-frame construction condo building:  The wired network runs fine, but I want to supply 802.11g and n to all. The switch does POE, Ive a power injector, and have configured the 1252 no problem.  The two radios in the 1252 will support six antennas - three 2.4ghz and 3 5 ghz - but Im clueless as to what to buy or what to locate them. The roof is easy, as is the ceiling of the basement garage:  both are already wired with Cat 5E.  Locating the WAP anywhere else will require additional wiring that Id like to avoid, but Im not averse to hanging upside down by my feet in order to wire antennas, if only I know which antennas to put where. Of course since the job is measured in hundreds rather than hundreds of thousands of dollars, my local Cisco partner in Seattle won return my calls.   Antenna advice would be much appreciated.  Ive spent a week becoming familiar with the issues, but am still not confident.  It seems likely much fussing will be involved, and that I might make a false start or two equipment wise, but Id at least like to increase the odds of getting it right as quickly as possible. Thanks,Bryan

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Re:Best Antenna Choices

Post by Guest » Fri May 29, 2009 1:58 am

The entire structure is all wooden, is this right?  Not a single slab of concrete/brick wall? Have a look at the AIR-ANT2451NV-R.  Heres the link: http://www.cisco.com/en/US/prod/collate ... 2451nv.pdf Pay close attention to the horizontal and vertical azimuth plane.  This will tell you what signal footprint each of the antennaes have. This model is designed to be used for the 1250, 1260 and 3500e. Please don forget to rate useful posts.  Thanks.

Guest

Re:Best Antenna Choices

Post by Guest » Fri May 29, 2009 2:14 am

The entire structure is all wooden, is this right?  Not a single slab of concrete/brick wall? The basement garage has a concrete shell, but its all wood starting slightly above grade.Have a look at the AIR-ANT2451NV-R Interesting.  One for the entire building?  Thats an indoor-only unit, which rules out the roof.  What do you suppose the best location would be? Thanks much,Bryan

Guest

Re:Best Antenna Choices

Post by Guest » Fri May 29, 2009 3:51 am

Look at the horizontal and vertical azimuth plane (aka vertical and horizontal footprint of the wireless signal) of the antennae.  Youll notice that its as good as going around in the vertical plane (red circle) but a "kidney-shape) on the horizontal (blue line).  Id recommend you deploy at least two APs. You have to play around with the location.  I can see few options: 1.  Center of the building on the top-most floor (roof wouldn make any difference except when doing maintenance) and one on the ground floor.2.  Top most floor left-most and ground floor right-most.  Not too much or half of the signal will go out of the building.3.  Two units on the second floor. If you can deploy 3 units then I can see one option #2 and the third unit will be on the 2nd floor and center of the floor. Hope this helps.

Guest

Re:Best Antenna Choices

Post by Guest » Fri May 29, 2009 4:58 am

I get the footprint idea...  I think.  Ive gone so far as to 3D model some of them and impose them on the cube of the building.  Im picturing a globular dumb bell shape, the azimuths being round and the elevations tending toward two-lobed. Let say I go with your #1 suggestion:  two WAPs with one AIR-ANT2451NV-R each, one in the center of the roof, and the other in the center of the garage ceiling.  That means half the roof units signal is being broadcast into space, and half the garage units into the ground, right?  The remaining two halves should still penetrate the building? Not that I doubt your advice, but because Ive become curious about all this...  Wouldn some directional solution provide more usable signal?  What am I missing? Also, your #1 idea leaves potential capacity for four additional antennas - a 2.4 and a 5 on the roof, and another pair in the garage.  Is there anything I do with that to increase the likelihood of good coverage and high bandwidth? I appreciate your taking the time to get me up to speed. -Bryan

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