The two types of spread-spectrum radio are direct sequence (DSSS) and frequency hopping (FHSS). Both are shown in Figure . They are based on the idea that a signal that is spread widely or that is quickly moving from channel to channel will be difficult to detect and hard to interfere with. DSSS generates a redundant bit pattern called a chip or chipping code, for each bit to be transmitted. FHSS uses a narrowband carrier that changes frequency in a pattern known to both the transmitter and the receiver. If everything stays properly synchronized this creates a single logical channel, even though the frequency is constantly changing. Early implementations of 802.11 used FHSS, however 802.11b standardized on DSSS.

Currently the 802.11a and 802.11g standards, operating up to 54 Mbps, use OFDM instead of DSSS. OFDM limits the crosstalk or interference of transmitting channels. OFDM is used in European digital audio broadcast services. Compared to DSSS, OFDM allows more speed. OFDM does not give up distance. In fact it facilitates longer distance capability. OFDM does require more processing power in the radio.

In addition to taking care to match transmission technologies, wireless network administrators must be aware that connection issues can also exist in changing environments where obstacles may block, reflect, or impede signals. Antenna choice and mounting location must be carefully considered when designing WLANs in order to avoid future interference. The connection will usually not be lost even though the available bandwidth may drop very low. Lack of guaranteed bandwidth is of particular concern for many companies.