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New Member

continue less congested channel topic

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,

Valery

2 REPLIES
Cisco Employee

Re: continue less congested channel topic

Valery,

I just want to be clear on what you are asking.

Is your problem that it wont scan at start up ?

Or is it that when the card has been running for a while then congestion is encountered it will not scan and move channels ?

If it is the first there is no option for scannning in ad hoc mode, infact you must manually configure all cards to the right channel.

From the documentation page

Specifies which frequency your client adapter will use as the channel for communications. These channels conform to the IEEE 802.11 Standard for your regulatory domain.

In infrastructure mode, this parameter is set automatically and cannot be changed. The client adapter listens to the entire spectrum, selects the best access point to associate to, and uses the same frequency as that access point.

In ad hoc mode, the channel of the client adapter must be set to match the channel used by the other clients in the wireless network.

If it is the second option, then even if there was a scanning option in ad hoc mode then if it was the same as the AP it will only scan at start up or if the radio is restarted for some reason such as a configuration change.

Ad hoc mode is really like using a cross over cable between 2 ethernet nic cards.

New Member

Re: continue less congested channel topic

Thank you,

I just wanted to know if such thing as frequency scanning for less congested radio channel using PCI adapter Cisco Aironet 350 Series cards is possible.

I see, that in ad hoc it is impossible, and in infrastructure mode it is run only at the start up by the AP.

Thank you for your time and explanations,

Valery

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