2.2.1 SPREAD SPECTRUM LANs
In exclusion of very small offices, a spread spectrum wireless LAN makes use of a multiple-cell arrangement. Each of the adjacent cells in the configuration is assigned a different centre frequency within the same band to avoid interference. With this transmission technology, there are two methods used by wireless LAN products frequency hopping and direct sequence modulation.
• Frequency Hopping: Here, the signal jumps from one frequency to another within a given frequency range. The transmitter device "listens" to a channel, if it detects an idle time (i.e. no signal is transmitted, it transmits the data using the full channel bandwidth. If the channel is full, it "hops" to another channel and repeats the process. The transmitter and the receiver "jump" in the same manner.
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