There are two basic infrastructure models for wireless set-ups.
Every station has a wireless connection to provide a self contained network.
A BSS can overlap with another BSS to provide a greater coverage area. Before 802.11, most of the wireless LAN products were DSSS and ran in the 902 - 928MHz range. DSSS Direct Sequence Spread Spectrum takes the normal narrow-band transmission and spreads it over a larger range, thus preventing interference from blocking out the entire signal. 802.11 defines 11 separate channels . For North America, they start at 2412 MHz and are spaced 5 MHz apart.