I sometimes found a spurious AP at channel 6 using ‘Network Stumbler’. Please let me know if there is something I can do in order to have the best possible signal at my second floor.
I read your article about interference. I would like to know if I can increase the power of my wireless in a stable way and get ride of any interference. My network design: First floor: Zyxel P660HW-61 as ADSL router and AccessPoint ( 802.11g and 802.11b ), channel 11. Second floor: Notebook WindowsXP SP2 with a 2100 3B 802.11b centrino wireless chipset. I have also a 1.88/1.9 GHz cordless phone always on and a Panasonic Microwave oven usually switched off. I sometimes found a spurious AP at channel 6 using “Network Stumbler.” Please let me know if there is something I can do in order to have the best possible signal at my second floor.
— Simone Chemelli
I recently came across a tool by the name of WiSpy. For $99, it turns your laptop into a basic spectrum analyzer. There is substantial documentation that is available on the Web site to help you identify different sources of interference.
I recently had a chance to use this tool when I installed a pair of access points to cover a medium size building. It started with being on top of a Cisco 1200 Series access point and not being able to “hear” it. I could see the one on the other side of the building but not the one near me. USing the WiSpy tool, I was able to identify a channel hopping 2.4 Ghz cordless phone as being the problem. Hopefully this tool might help point you in the right direction. As to increasing the power of the Zyxel access point/router, you may not have any options. Check the setup screens and see if you have any options for adjusting the power level. Some brands do let you do this, but Zyxel doesn’t appear to.
If your access point has detachable antennas, you can also look using a higher gain antenna to help boost the coverage area of your current setup. This might help drown out the interference or at least make it easier to establish a connection between your laptop and the access point. Your local computer store might have some of the extended gain antennas that should do the job for around $30.
If they don’t have anything on hand, you can look at some of the online vendors for options that they have available. One vendor that I have used in the past when looking for different Wifi antennas to solve coverage problems is Fleeman, Anderson and Bird.
If changing antennas doesn’t work, you may need to consider a secondary access point. Over the years, I have had situations where even with changing antennas on the access point, I couldn’t provide consistent coverage between floors in a building. It is also might be worth turning off the wireless phone to see if it might be either the cause of the problem or at least a contributing factor.
