Patent ID: 7058113

Claim:
A radio LAN (Local Area Network) system comprising an access point forming a limited service area and a station present in the limited service area for transmitting by radio an information signal between the access point and the station within the service area: each of said access point and said station comprising: a transmitter for spreading the information signal with a direct spread spectrum system, which spreads a frequency band width of the information signal, and transmitting a spread information signal; and a receiver for receiving the spread information signal and inversely spreading said spread information signal; said transmitter comprising: a plurality of information transmitting circuits each for multiplying, in a direct spread spectrum system, the information signal and particular one of a plurality of spread codes; and a transmission controller for selecting, in accordance with at least one of a kind and an amount of the information signal, one of frequency bands and frequencies respectively assigned to said plurality of information transmitting circuits and one of packets to use for transmission of the information signal, and maintaining transmission power of the spread information signal semi-fixed; said receiver comprising: a plurality of information receiving circuits each for detecting synchronization of the information signal received, multiplying the information signal detected by particular one of a plurality of codes for inverse spreading, said plurality of information receiving circuits determining a correlation between resulting multiplied information signals to restore the information signal originally sent from said transmitter; and a receipt controller for maintaining received power of each spread information signal output from each of said plurality of information receiving circuits semi-fixed, and guaranteeing a level of the spread information signal; said access point further comprising a first interface for connecting said access point to a wired LAN; said station further comprising a second interfacing circuit for connecting said station to either one of a public switched telephone network and a terminal configured to process the information signal.