Embedded systems for Wireless Local Area Network (WLAN)

Wireless System

WLAN standards

You can find a variety of products to deploy wireless local networks (WLANs). The product's specifications vary depending upon the various wireless standards. To deploy a WLAN you must analyze these standards for wireless products. These standards include 802.11, 802.11a, 802.11b, 802.11g, and Bluetooth®. All these standards show their own advantages and disadvantages that I cover below.

IEEE 802.11 Wireless LAN standard

It was the first wireless standard introduced in 1997 by IEEE (Institute of Electrical and Electronics Engineers). It uses unregulated radio frequency signaling of 2.4 GHz (Giga Hertz). 802.11 was the name of the group who developed it. With maximum bandwidth of 2 Mbps (Mega bits per second), it is too slow for many applications as well as traditional Ethernet. This is the reason you do not find new 802.11 wireless products.

IEEE 802.11b Wireless LAN standard

To overcome bandwidth issue IEEE came up with 802.11a and 802.11b wireless standards in 1999. 802.11b gained much more popularity in vendors just because of its low cost due to unregulated radio frequency (2.4 GHz). Unregulated frequency means that other products using same 2.4 GHz radio signaling can interfere with each other. Examples include cordless phones and microwave ovens. Well interferences can be avoided by keeping the various systems away. This standard supports the bandwidth of 11 Mbps. This bandwidth is also comparable to traditional Ethernet. The advantages of the 802.11b over others standards is its lower cost and the best signaling that can hardly be obstructed.

IEEE 802.11a Wireless LAN standard

IEEE 802.11a standard was also introduced in 1999 with 802.11b standards. The reason it could not gain much popularity was its higher production cost due to regulated frequency (in a spectrum around 5 GHz). Its major advantage is higher bandwidth of 54 Mbps. Moreover using regulated frequencies does not cause any interference. The disadvantage is its short range of signaling that can easily be obstructed from walls. Other disadvantage is its higher production cost.

IEEE 802.11g Wireless LAN standard

In late 2002 and early 2003 IEEE introduced 802.11g wireless standard. The effort was to combine the both the advantages of IEEE 802.11a and 802.11b standards. It offers 54 Mbps bandwidth (802.11a) for higher data rates. It uses unregulated radio frequency signaling (802.11b) for longer distances without obstruction. Its other advantage is backward compatibility with 802.11a and 802.11b standards products. Interference due to unregulated radio signaling and higher cost than 802.11b standard are its disadvantages.