- Both 802.11a and 802.11b were produced in 1999. They described two incompatible systems aimed at different markets. The 802.11a standard yielded a fast but expensive wireless network. The 802.11b standard used cheaper equipment and so came within the price range of home electronics. It was 802.11b that started the home Wi-Fi network market. The main reason 802.11b is cheaper to produce is its use of a lower frequency of radio wave. A lower frequency can be generated by cheaper equipment. The 802.11a standard used a 5 gigahertz frequency, whereas 802.11b uses a 2.4 gigahertz frequency.
- Wi-Fi networks use a process called modulation. The transmitter generates a carrier wave. Each block of data is converted into a square wave and the two waves are merged before they are sent out. This means that the faster waves are generated, the faster data can be sent out and so more data can be sent faster. A higher frequency means that wave generation is more frequent. The waves are thinner and there are more of them per second.
- The 802.11g standard was introduced in 2003. It improved on 802.11b by borrowing methods from 802.11a and its better performance increased the consumer uptake of Wi-Fi technology. However, the cost of generating a 5 gigahertz frequency was still not within the range of consumers by 2003, so 802.11g still used the 2.4 gigahertz frequency. The 802.11g standard also uses a form of modulation called Orthogonal Frequency Division Multiplexing. This cuts up each carrier wave into sections, producing sub-carriers. Each sub-carrier carries a packet of data, giving 802.11g much greater throughput than 802.11b.
- The 802.11g recommendations achieve a clear data throughput of 54 megabits per second. This is a great improvement on the 802.11b throughput rate of 4.5 Mbps. The latest version of the Wi-Fi standards is 802.11n, which can achieve data throughput of up to 600 Mbps.
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