Posted 03 January 2010 - 01:41 AM
I copied this from somewhere else. But it does a good job splaining it all
The problem is in the way that 802.11b/g operates and the way that many cordless phones operate.
Wifi (802.11b) is a direct sequence spread spectrum technology, that is in the 2.4 - 2.483 ghz spectrum, Wifi uses channels that are 22 mhz wide, at each channel center point Wifi hops 11 mhz down, and 11mhz up from the center of the channel, 400 times per second.
the "unlicensed" bands, such as 900mhz, 2.4ghz, 5.8ghz are just that, unlicensed, meaning that anyone can develop any technology they want to utilize the spectrum. The FCC regulates this simply by putting parameters on the EIRP (Equivalent Isotropically Radiated Power) emitted at the antenna, in 2.4ghz, not to exceed 4 watts. the presumption being that this would curtail people stomping on each other to some degree.
Most modern cordless phones use Frequency Hopping Spread Spectrum, and typically do it across the entire available spectrum. BlueTooth is also a FHSS technology. While cordless phones are typically proprietary in their use of FHSS as far has hop sequences and how many times per second they change frequencies, it can be similar to BlueTooth which hops at 1600 times per second across the entire 2.4ghz range.
What does all this mean?
In order for your Wifi device to communicate it must be able to distinguish data signals from background noise (such as microwaves, cordless phones, bluetooth). The higher the "noise floor" the more signal strength you need between your wireless access point / router and your client device. When the difference between noise floor and received signal strength is not sufficient the data packet won't be seen.
Additionally, and more common, since these FHSS devices are typically hopping thru the entire sprectrum at a must faster rate then your wifi, they have a much greater chance of sending signal on the exact same frequency at the exact same time as your wireless, each signal currupting the other and causing the devices to use whatever mechanism has been designed to deal with such issues.
For Wifi, every packet sent by either side of the communication is to be acknowledged by the receiver. If no acknowledgement is received, then the sender "resends" the data packet. Potentially dramatically reducing performance.
Even phones that market them as 10 channel phones, don't really behave well in these environments, because they are typically constantly searching, probing the available channels for the "least congested" place to do business.
You could have gotten a router that when mixed with your phone could have caused issues or not. So there is no real way of knowing. But if you still have the 2.4 phone when you switch to N (or whatever will be around then) you can use it again. lol
Hope this helps
Associate in Applied Science - Network Systems Management - Trident Technical College