Change Wireless Region

Take a look at the attached picture. It shows channels usage in my neighborhood.

I have tried channel 3, 8, and 13 and compared the result. I found channel 13 gives the best result in covering my house. Unfortunately, I cannot use it in just one of my laptop. I have 2 PCs and 2 laptops working with channel 13.

Yes, it is clear why - it only partly interferes with acess ponits on ch11. On other channels you have interference on both sides (nice pic, where did you get it from?)
Have you tried to download driver and software directly from intell?
http://www.intel.com/support/wireless/wlan/4965agn/

Updating the driver and software was not useful. I cannot connect to channel 13.

Is wireless regional setting depends on hardware or software? I will try booting using Linux (Ubuntu) to see if its software related.

PS: I used inSSIDer (http://www.metageek.net/products/inssider) to capture wireless signals in my neighborhood.

Let me know the result. I vote for SW. Thx for link.

Unfortunately, the test using Linux was not successful. It is not OS or driver related, possibly BIOS or hardware.

I have a strong believe on hardware limitation. However, I searched the BIOS configuration and no such parameter for Wi-Fi. I dont know if I need to update the BIOS firmware from Sony Europe or Japanese support site.

In any case, I bought a USB wireless adapter for the laptop.  As a workaround, I am using it instead of the internal one to connect on channel 13.

Hi,
are you using ubuntu? There is a bug in drivers, taht do not allow using ch12&13
http://www.ubuntu.com/getubuntu/releasenotes/810#Only%20US%20wireless%20channels%20enabled%20by%20default%20on%20Intel%203945
There is also workaround - maybe it will apply also to you.

All workarounds (option file and iw command) with Ubuntu 9.10 did not work.

I need to use a channel with low interferance to have best coverage. A channel that is supported by all wireless adapters in my home. I am thinking to use the 5GHz band. All of PCs and Laptops support it. My AP can support it. The problem will my PlayStation3 support this band. I dont think so. but I will have to try.

You should always use 5Ghz band ----
in 5Ghz there are more channels and fewer interfering devices and most likely fewer other APs nearby.
only drawback is that you'll get a bit smaller coverage.

But 5Ghz is the solution ---

Thanks Jakob, but the 5Ghz is not supported by my PS3.

Well --- looking at your survey with inSSIDer, channel 1 would be the best to use for you.

Even so - no matter how many APs that's within your reach computer - there has to be a lot of them to really interfere with your network so much that it will influence your wireless performance.
So given the PS3 limitations, and design limitations of 802.11b/g - your stuck with ch 1,6 or 11

Do you experience any problems with wireless performance or is just looking at different channels as a precausion?

I have coverage problem. The signals will drop if I move the laptop in any different room. Ch13 was my solution to cover the hole apartment. I had a working solution but limited to some laptops. I could not enable ch13 in just one laptops (the newest one).

Have you tried using inSSIDer and doing survey from every room with channels 1, 6 and 11.
Channel 13 shouldn't have any greater coverage than the other channels ---

I did the survey in all channels. The best one is channel 13.
If I choose channel 1, 6 and 11, my neighbors signal will override my signal immediately after moving to another room. That results in lose of signals.
Also, I found that channels 3 and 8 are slightly better that 1, 6 and 11.

Could you try to use WLAN range extender (example - linksys WRE54G - better to look for the same brand) and configure your network on Ch3?

if you use channel 3, you'll get interference for all APs at channel 1 and channel 6.
But, then again - if it works for you - use it. And you could try range extender, but still - i find it odd that neighbouring AP totally kill you signal.

Have you got any possibility to move the AP, if just to check? Try adjusting antennas.What WiFi router do yoiu have?

Range extenders will not work as there is no signal outside my living room (AP location.) The extenders are useful in case you have coverage problem due to distance limitation. My problem is the high interference.

I have Linksys WRT610N. Changing its location to another room did not help in reducing the interference in the other (non AP) rooms.

I thought of those power line adapters with wireless such as the Netgear Powerline. Maybe I can connect one in the living room and one in each room. But I have several concerns in such solution. First, the solution could be more expensive than buying a new laptop. Second, the quality and bandwidth of the network could be affected. Also, I could have some rooming problem.

Anyway I think we have shifted from the main subject that is changing the region of wireless adapters. I thought that changing the region in my wireless adapter is cheaper and possible. The same way we change AP region. I dont want to use any kind of extenders and loss more money. If there is no solution to change the region, then I have to live with the current status.

Thank for all for your kind help.

Changing region on wireless equipment is not easy, and in some cases not possible.
Did you say what router you have?

Sorry --- to quick on the button. You said WiFi card.
Where do you live? Japan/Europe? laptop bought there?

Look at this: http://download.intel.com/network/connectivity/products/prodbrf/Intel_Wireless_WiFi_Link_4965AGN_User_Guide.pdf

Sadly, nothing on changing region - but as long as it's EU/JPN you have 1 - 13

My router is Linksys WRT610N.

My location is Dubai (United Arab Emirates). We suppose to follow the EU region. I bought the laptop from gitex shopper (a computer exposition) in Dubai.

Can you create more than one SSID on your router?
if so:
Create SSID1 - 802.11a/n - used for all laptops (WPA2/AES - PSK - if possible) - ex: 10.10.11.0 - 255.255.255.0
Create SSID2 - 802.11b/g - used for PS3 (same encryption) - ex: 10.10.12.0 - 255.255.255.0

Then create filter and firewall rules to guide traffice from SSID 1 to SSID2. Allow any from 10.10.12.0 to 10.10.11.0 and vice versa.

Looking at my Intel 3495, using ProSET admin tool (http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Wireless+Networking&ProductLine=Intel%C2%AE+WiFi+Products&ProductProduct=Intel%C2%AE+Wireless+WiFi+Link+4965AGN)
i cannot extend channels beyond 11

You will have to move ;)
I have mentioned range extender, because the idea was that. Stronger the interfering signal is, more troubles you will have. If you ampify your signal, less interference you will notice. Closer to the router you are, stronger is the signal - less interference you have.
If you place exterder inside the exsisting range, you will boost the signal strenght in that range.
Regarding the attached picture the signal levels are not so high - below -70dB. I have tested signal strentgh thru concrete-steel wall and it was -50dB. That is 20 dB of difference and if I remember correcty every 3dB is doubling the strentgh.
But I suspect, that your neighbors will not share your joy.
Unfortunately your router does not allow to change the antena. If you had antena that emits signal to directions you need, the signal willbe stronger in that direction and your neigbours would have less interference.