Wireless Networks - Standards

802.11b

IEEE 802.11b operates in the 2.4 GHz unlicensed ISM band. 802.11b became a standard in September 1999. It defines Direct Sequence Spread Spectrum (DSSS) RF technology operating at data rates of up to 11 Mbps. Because IEEE 802.11b is a standard, products from different vendors can interoperate together.

802.11a

802.11a uses the less congested 5 GHz band which avoids potential interference from cordless phones and microwaves. 802.11a is not interoperable with 802.11b unless you are using equipment that implements both standards. 802.11a uses orthogonal frequency-division multiplexing (OFDM) and supports data rates up to 54 Mbps.

802.11g

In 2003, a third wireless standard called 802.11g was introduced. 802.11g works in the 2.4 GHz band but uses orthogonal frequency-division multiplexing (OFDM) to obtain higher data speeds. The 802.11g specification offers speeds of up to 54 Mbps. 802.11g hardware is compatible with 802.11b hardware, however with an 802.11b device in the network your speed will drop dramatically.

802.11n

802.11n is still in the draft stage. The new specification adds technology called multiple-input multiple-output (MIMO), a signal processing and smart antenna technique for transmitting multiple data streams through multiple antennas. This allows 802.11n to achieve maximum data speeds of approximately 200 Mbps, delivering bandwidth ideally suited for video streaming. 802.11n is compatible with previous generation 802.11a/b/g, but speed and performance will drop if an 802.11a/b/g device joins the network.

WiMAX

WiMAX (Worldwide Interoperability for Microwave Access) is based on the IEEE 802.16 standard, which is also called WirelessMAN. New WiMAX equipment will be capable of sending highspeed data over long distances - 40 Mbit/s over 10 kilometres in a line-of-sight fixed environment. At these distances, WiMAX equipment could play a key role in helping bridge the digital divide as long-distance
wireless links could help deliver higher-speed access to areas traditionally out of reach of fixed-line networks. WiMAX has also been attracting particular interest as a disruptive technology that could impact fixed and mobile markets, in both their voice and data segments. Finally, WiMAX has also been tapped as a potential key component of next-generation converged or ubiquitous networks.