802.11 Channel Interference

[Indraneel Chakraborty]

Hello List Members,
	In IEEE 802.11b which is using Direct Sequence Spread Spectrum we can have only 3 non-overlapping channels.  But do you have any analysis or pointer about how the available bandwidth would change per channel if one uses the overlapping channels?  say channel 4 and 5 or 4 and 6? What about 802.11a with OFDM? I understand that what keying mechanism you use would affect the final bandwidth achieved, but then what's the raw channel throughput in these cases? What would be the practical throughput in each case of interference? 
	Every help would be greatly appreciated,
Thanks,
Indraneel