Scanning Access Points configured with JAPAN Channels

Unanswered Question
Apr 23rd, 2008
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I have configured the below mentioned configuration for my Access Point. These wireless networks are not appearing in windows client network list. I have tried explicit scan also. Still it is not showing networks with 184,188 channels. But it is showing all remaining networks.

Country code: JAPAN

SSID for WLAN 1: Wireless Network1

WLAN 1 mode: 5 GHz 54Mbps (802.11a)

WLAN 1 auto channel: Enabled

WLAN 1 channel: 184 (4920MHz)

WLAN 1 alt. channel: 188 (4940MHz)

SSID for WLAN 2: Wireless Network2

WLAN 2 mode: 5 GHz 54Mbps (802.11a)

WLAN 2 auto channel: Enabled

WLAN 2 channel: 188 (4940MHz)

I am using CISCO AIRONET 802.11a/b/g WIRELESS ADAPTER. This problem can occur due to the following reasons.

(1) Do I need to set any region settings at Adapter?

(2) Does adapter firmware depends upon

country? How do I check the adapter firware?

(3) Is there anything wrong with adapter vendor driver? Do I need to set anything in driver level for supporting JAPAN channels.

Anyone please help me to identify and resolve the above problem.


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Anonymous (not verified) Tue, 04/29/2008 - 13:18
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What channels are available? The 802.11b standard defines a total of 14 frequency channels. The FCC allows channels 1 through 11 within the U.S.; whereas, most of Europe can use channels 1 through 13. In Japan, you have only one choice: channel 14.

An important concept to note regarding channel assignments is that the channel actually represents the center frequency that the transceiver within the radio and access point uses (e.g., 2.412 GHz for channel 1 and 2.417 GHz for channel 2). There is only 5 MHz separation between the cente frequencies, and an 802.11b signal occupies approximately 30 MHz of the frequency spectrum. The signal falls within about 15 MHz of each side of the center frequency. As a result, an 802.11b signal overlaps with several adjacent channel frequencies. This leaves you with only three channels (channels 1, 6, and 11 for the U.S.) that you can use without causing interference between access points.


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