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New Member

Can I use one omni antenna with a 350?

It seems there is no point to use diversity with two omnidirectional antenna's on an access point since the AP will only use the antenna with the best reception, is that a safe bet? Will the 350AP work fine if I configure it to use only one antenna for Tx and Rx or is that the recommended configuration? I can't find anything on Cisco's web site that discusses the details of using removeable omni antenna's or how the AP determines which antenna to use by means of "best reception." Best reception from the first client that comes up or some kind of running average?

Thanks a lot for the help,

Brock Henning

4 REPLIES
New Member

Re: Can I use one omni antenna with a 350?

The reason there are two antennas, is to solve multipath RF problems. This is similar to when you are in a car at a stop sign and the radio sounds bad. If you roll forward a few feet the signal gets better. The AP does this by swapping antennas. I have seen different antennas on an AP. The trick is to make sure the covered area is the same.

New Member

Re: Can I use one omni antenna with a 350?

The 2.2dBi you'll get from the stock antennas gives you minimal coverage.

Moving to a single 5dBi or higher will give you better results - specificly, you will maintain 11Mbps further from the AP.

Aftermarket antennas give you both better gain and better options for placement.

Don't forget that antenna selection can be viewed as the first step in securing your wireless network - if the signal only exists where you want it, you'll worry less about that black van in the parking lot.

New Member

Re: Can I use one omni antenna with a 350?

Thanks to you and the other individual that responded. I've got both 5dBi antenna's connected and running in diversity mode, and it seems to be working okay. I've noticed using the Cisco site survey tool that my signal quality seems just fine (around 98%) but signal strength hovers around 70% to 85% within close proximity (about 30 to 50 feet) and with a clear line of site. Seems the high gain antenna's at 100mW would have better signal strength. There are no 2.4GHz phones or microwaves being used, and no known equipment that would operate in that frequency range. Any ideas why signal strength is only in the 95%+ range when I'm within 10 to 20 feet of the antenna? I know placement can make all the difference here, and I'm learning as I go.

Thanks again for all your help,

Brock Henning

New Member

Re: Can I use one omni antenna with a 350?

95% is a lot. Don't forget that signal strength falls of very quickly going through air.

When you run the Site Survey, make sure to use the dBm option rather than %. You'll be able to see the raw signal strength and the noise value from which the signal quality rating is derived.

You can also try different client cards, different client antennas (if you have an LMC card) or the same card at a lower power setting if you are concerned that there is a sudden drop off in any given area.

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