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New Member

Less-congested Radio Channel feature


Cisco Aironet 350 Series Wireless Bridge has the option "Search for less-congested Radio Frequency". Once activated, this option scans all possible channels of communication in ISM band, 2.4GHz and choose the least congested one. In case that an interferention appears, the bridge changes the channel and the second bridge of the pair re-associates to the new channel frequency in 2.4 GHz band.

I'm using Cisco Aironet 350 Series Wireless PCI Cards for wireless communication and I would like to know if such an option, as scanning the least congested radio frequency may be the part of the firmware of PCI Cards?

For example, other wireless products (Linksys, SCM,etc) support frequency scanning, starting from some firmware version.

The part of frequency change should require both sides to communicate their intentions and switch channels at the same time, but the mechanizm of finding the least congested channel remains still unclear.

Could you please answer, if it's possible to use this feature with PCI Cards, Cisco Aironet 350 Series?

Thank you,


Cisco Employee

Re: Less-congested Radio Channel feature

All 802.11 client devices scan all channels to find valid AP's

It is the AP that decides the channel.

It should be noted that the bridge and AP will only scan for less congested channels at start up and if a major change has been made to the radio config.

Here is the documentation that describes this feature

This link will describe the settings for the client card the section on channel assement should answer your question on how it determines if the channel is congested or not

You will find all the feature that are on PCM cards are also on PCI cards, some of the features described here are only in the latest firmware ACU and NDIS combo

New Member

Re: Less-congested Radio Channel feature

I'm using Cisco Aironet PCI cards in Linux, when one mashine is playing the role of AP and the other is a client. The problem is that once assigned the channel remains the same on the client and AP mashine. I'm looking for a solution for this problem, the possibility to scan the channel frequencies, for example initiated by the network manager, finding the least congested one on the AP side, changing the channel of the AP, and, as I expect, the client re-assosiates automatically to the AP, looking for the wanted SSID.

The question is - what is the mechanism of frequency scanning and how AP decides which channel is the least congested one.

Thank you for your help,


New Member

Re: Less-congested Radio Channel feature

hie ,

this depends on which mode of operation you are using

if it is infrastructure then the AP will decide the channel

and if it is point to point adhoc between two wireless cards.. then both the cards willl decide the channel.


regards......... sandeep