## Radio Basics

IEEE 802.11 networking devices transmit and receive radio signals. Users communicate with the network by establishing radio links between mobile devices and access points, or between each other.

| WARNING: A minimum separation distance of 20 cm (8 inches) should be maintained between the radiating element of this product and nearby persons to comply with FCC rules for Radio Frequency (RF) exposure.

IEEE 802.11 devices use frequency modulation (FM) to transmit digital data from one device to another. The radio signal propagates into the air as electromagnetic waves. The receiving device demodulates the signal, which results in the original digital data. The radio devices transmit in the frequency ranges from 2.4 to 2.5 gigahertz for 802.11b networks and 5.15 to 5.35 gigahertz for 802.11a networks. These are license-free ranges throughout most of the world. The actual range is country-dependent.

### Direct-Sequence Spread Spectrum (DSSS)

Broadband spread spectrum uses an algorithm to spread the transmission of a narrowband signal over a segment of the radio frequency band or spectrum. DSSS is a spread spectrum technique in which the narrowband signal is combined with a "chipping sequence" to spread the radio signal sequentially across the entire frequency range specified by the channel of operation. The Intel® PRO/Wireless 5000 LAN Access Point uses DSSS for radio communication.

| NOTE: In the United States, the three non-overlapping direct-sequence channels are channels 1, 6, and 11.

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