Broadband W-LAN So What Is 802.11 about?

The key drivers of demand for broadband wireless access networks are rapid
growth in wireless and mobile communications, the emergence of multimedia
applications, and the need for high-speed Internet access, led by the telecom
deregulation.

Today’s primarily narrowband wireless services are mostly used for
circuit-switched voice services. The evolution of second-generation and the
development of third-generation mobile wireless systems aims to enable networks
to provide instantaneous user bit rates of up to 2 Mbps per radio channel. This
capacity will significantly improve packet-data and mobile multimedia
applications. In addition, even higher data rates could be obtained for local
area networks (LANs) using novel short-range wireless technologies. Typical
applications are bandwidth-hungry, real-time and interactive multimedia services
such as high-quality video distribution, client/server applications, and
data-bank access.

LANs have ubiquitous presence in most networked offices. Only problem is that
they have traditionally been tied to wires, thus restricting user freedom.
Wireless, which offers that freedom, is now entering the realm of LAN. However,
till now, wireless-LAN has been at an embryonic stage.

Different Options, Different Speeds

802.11–the first IEEE wireless LAN standard/protocol to emerge–offered a
data speed of 1—2 Mbps, not enough to meet the needs of today’s broadband
applications.

The two latest versions of 802.11, denoted by suffixes ‘a’ and ‘b’,
promise vastly improved speeds.

802.11b offers a speed of 11 Mbps operating at 2.4GHz. It has seen market
penetration mainly in niche applications such as buildings where the new cabling
presents a problem. 802.11b offers benefit of a 100-m range, but requires ten
times more power support than Bluetooth. The high power draw may make it a less
attractive proposition for mobile communication devices such as PDAs and
notebooks, but the range makes it ideal for LAN applications. It operates on a
‘hopping’ basis, switching frequencies every 2.5 seconds. By wireless
standards, this is a relatively slow switching sequence, making it somewhat
susceptible to interference. For comparison, Bluetooth shifts frequencies 1,600
times per second.

802.11a offers broadband connectivity to the Internet in a LAN. Currently
under development, it is expected to provide an impressive 20—50 Mbps speed
while operating at 5.1GHz.

Applications Galore

The advantage that the wireless connectivity offers over other wired Internet
connectivity alternatives like fiber is that it adds the mobility dimension to
devices. It makes rollouts faster, rapidly increasing new subscribers. Not only
it is convenient for the mobile user, it is also the easier way to connect home
networks. The spectrum used for connectivity is likely to be cheaper and
unregulated.

Traditionally, W-LANs have seen applications in markets such as healthcare
and warehousing, where companies can justify high equipment and integration
costs. But recently, the applications have grown into mainstream businesses,
homes and educational environments as well. With the number of devices in a home
multiplying, there is a need to connect them. Wireless LAN offers the best
solution for the purpose.

Niraj K Gupta www.telecombyNirajGupta.com