y Today several 802.11 standards exist. 802.11b and 802.11g devices trans- mit in the unlicensed 2.4 GHz range, while 802.11a devices transmit at 5 GHz. Needless to say this presents a radio compatibility problem that had to be overcome. As far as implementation history is concerned, 802.11b was the first version of the Wi-Fi standard to reach the market. It is the least costly and offers the lowest bandwidth of the three, trans- mitting in the 2.4 GHz spectral band at speeds up to 11 Mbps. Next in the developmental lineup was 802.11a. Operating at 5 GHz, it can handle transmission speeds up to 54 Mbps. Its biggest challenge, however, was its incompatibility with the widely accepted 802.11b To remedy this, 802.11g was introduced, which operates in the same 2.4 GHz band as 802.11b but offers transmission rates at speeds equivalent to 802.11a-upward of 54 Mbps. As a result, it is not only compatible with 802.11b but also benefits from the lower cost, unlicensed spectrum at 2.4 GHz. To achieve the high-bandwidth levels that these systems offer, innov- ative data encoding techniques are used. One of the most common, employed in 802.11a and 802.11g, is called orthogonal frequency division multiplexing (OFDM). OFDM divides the radio signal into multiple sub- signals, which are then transmitted simultaneously across a range of dif- ferent frequencies to the receiver. 802.11b, on the other hand, uses a different encoding technique called Complementary Code Keying (CCK). As one knowledge base defines it, complementary codes are "binary complementary sequences with the mathematical property that their periodic auto-correlative vector sum is zero except at the zero shift." And while that definition may set the engi- neers in the audience all aquiver, it makes me feel like I'm reading the bridge column in the newspaper. So, in English, CCK is simply a tech- nique that creates a set of 64, eight-bit "code words" that encode data for 11 Mbps data transmission in the 2.4 GHz band (802.11b). These code words are mathematically u