WLAN or Wi-fi is the hottest wireless technology in circulation these days. What is the one big reason for the growing popularity of WLAN? You guessed it right: mobility. As more and more people in home, offices and in transit (at airports, hotels and restaurants) use devices like laptops and handheld PDAs, their yearning for an unfettered access to a high-speed Internet connection too is growing. In the highly networked markets of US and Europe, wireless LANs are popular because of four main reasons—user mobility, speedy and less cumbersome installation, installation flexibility, and scalability.

Technology Options

n Standards at a Glance: At present, globally there are two main types of WLANs—802.11a and 802.11b—based on the standards established by the Institute of Electrical and Electronics Engineers (IEEE). The latter has been around for years and is the most widely adopted, while the former was introduced more recently and is in the nascent stage of acceptance by equipment vendors. The significant differences between the two are that 802.11a offers a faster connection than 802.11b and operates on spectrum that is less cluttered than 802.11b. Then there are newer variations on these two offerings, such as 802.11g, 802.11e and 802.11i, which in essence are enhancements to the existing standards, offering greater compatibility, flexibility and security to Wi-Fi networks. 802.11b offers a throughput of 11 megabits per second theoretically (practically its 5.5 Mbps) and operates on the 2.4 GHz band, while 802.11a offers a connection speed of 54 Mbps and runs on the 5 GHz band.

n 802. 11g: The 802.11g standard is a combination technology that is compatible with 802.11b and uses the 2.4 GHz band with a data rate comparable to that of 802.11a. As 802.11a runs on the 5 GHz band that is regulated in India and is unlikely to be offered to private enterprises for use at least in the near future. So enterprises can look forward to deploying 802.11g. Besides offering five times more throughput than 802.11b, 802.11g is backward compatible with 802.11b. This enables an access point built for 802.11g to connect 802.11b if that is all that is available. A laptop with 802.11b capability and a tablet PC with 802.11g, for instance, can use the same base station.

n 802. 11a: Given the fact that the 2.4 GHz band is too crowded and interference prone, it is believed that 802.11a could well become the future standard of all WLAN deployments. That’s because it operates in the cleaner 5 GHz band (exactly between 5.15–5.35 GHz and the 5.725–5.825 GHz) and offers higher bandwidth (54 Mbps). The benefits of this standard are greater scalability, better interference immunity, and significantly higher speed. However, for all these benefits to reach user, the government would have to deregulate the 5 GHz band.

n 802.11b: 802.11b wireless networking consists of the stations or hubs, access point and ports. A Station (STA) is a network node that is equipped with a wireless network device. A personal computer with a wireless network adapter is known as a wireless client (i.e. laptops using wireless PCI cards). Wireless clients can communicate directly with each other or through a wireless access point (AP). Wireless clients are mobile. A wireless AP is a wireless network node that acts as a bridge between STAs and a wired network. The wireless AP is similar to a cellular phone network’s base station. Wireless clients communicate with both the wired network and other wireless clients through the wireless AP. Wireless APs are not mobile and act as peripheral bridge devices that extend a wired network. A port is a channel of a device that can support a single point-to-point connection. For IEEE 802.11b, a port is an association, a logical entity over which a single wireless connection is made. A typical wireless client with a single wireless network adapter has one port and can support only one wireless connection. A typical wireless AP has multiple ports and can simultaneously support multiple wireless connections. The logical connection between a port on the wireless client and the port on a wireless AP is a point-to-point bridged LAN segment—similar to an Ethernet-based network client that is connected to an Ethernet switch.