Wireless LAN Primer, part 1

Residential users, businesses, and service providers can benefit from
understanding wireless LANs (WLANs). Compared to wired LANs, wireless systems
can be faster to deploy and cheaper to operate. As throughput and
interoperability increase and equipment costs decrease, WLANs have become a
realistic alternative to wired counterparts.

Market opportunities
In small- and home-office markets,
residential gateways are leveraging wireless technologies to eliminate costly
inside wiring fees, while simplifying shared Internet access deployment in
single-family homes and multi-unit dwellings.

In the enterprise market segment, wireless systems are being used to provide
untethered LANs in shared spaces — like conference rooms, and hard-to-wire
locations — like warehouses. While the gear required to setup these networks
becomes increasingly cost-effective and our understanding of the technology
deepens, WLANs are a viable alternative to wire-bound office LANs.

Fixed wireless technology is a big part of the emerging Public Access
Broadband market, providing temporary high-speed Internet access at hotels, airports, libraries,
and convention centers.

Big bucks, no whammies

Increasingly, WLAN technology is being used
to offer fixed
wireless Internet access
. By connecting customer premise radios to ISP-owned
Access Points (APs), “wireless local loops” can be a lucrative broadband service
venture.

Potential revenues represented by these services are staggering. According to
Frost &
Sullivan
, the WLAN market grew 43 percent in 1999, and is estimated to reach
$1.8 billion by 2006. Although products differ for each application, the
underlying technology remains the same — IEEE 802.11. In this primer, we explain
the nuts and bolts of 802.11 Wireless LANs.

In the beginning

In your basic 802.3 Ethernet LAN, Cat5 cable
connects LAN stations to a hub. In a wireless LAN, Cat5 cable is replaced by a
radio channel, connecting stations to wireless Access Points (APs). Each
wireless station — laptop, desktop, or server — has a radio Network Interface Card
(NIC). APs are essentially hubs, outfitted with a radio transceiver, Ethernet
uplink, and 802.1d bridging software. Wireless stations transmit to an AP over a
shared channel, carved out of the unlicensed 2.4 GHz band.

Approved in 1997, the original IEEE 802.11 standard uses the 2.4 GHz band to
provide shared bandwidth at a maximum rate of 1 to 2 Mbps. In 1999, the IEEE
approved the 802.11b High Rate (Wi-Fi) amendment, increasing the rate to 11
Mbps. Together, these standards specify WLAN Physical (PHY), Media Access
Control (MAC), and Logical Link Control (LLC) layers for fixed wireless
broadband access and WLANs.

Residential users, businesses, and service providers can benefit from understanding
wireless LANs (WLANs). Compared to wired LANs, wireless systems can be faster
to deploy and cheaper to operate. As throughput and interoperability increase
and equipment costs decrease—WLANs have become a realistic alternative
to wired counterparts.

Market opportunities
In small- and home-office markets, residential gateways are leveraging
wireless technologies to eliminate costly inside wiring fees, while simplifying
shared Internet access deployment in single-family homes and multi-unit
dwellings.

In the enterprise market segment, wireless systems are being used to
provide untethered LANs in shared spaces—like conference rooms, and
hard-to-wire locations—like warehouses. While the gear required to
setup these networks becomes increasingly cost-effective and our understanding
of the technology deepens, WLANs are a viable alternative to wire-bound
office LANs.

Fixed wireless technology is a big part of the emerging Public Access
Broadband market, providing temporary high-speed Internet access at hotels,
airports, libraries
, and convention centers.

Big bucks, no whammies
Increasingly, WLAN technology is being used to offer fixed
wireless Internet access
. By connecting customer premise radios to
ISP-owned Access Points (APs), “wireless local loops” can be a lucrative
broadband service venture.

Potential revenues represented by these services are staggering. According
to Frost
& Sullivan
, the WLAN market grew 43 percent in 1999, and is estimated
to reach $1.8 billion by 2006. Although products differ for each application,
the underlying technology remains the same—IEEE 802.11. In this primer,
we explain the nuts and bolts of 802.11 Wireless LANs.

In the beginning
In your basic 802.3 Ethernet LAN, Cat5 cable connects
LAN stations to a hub. In a wireless LAN, Cat5 cable is replaced by
a radio channel, connecting stations to wireless Access Points (APs).
Each wireless station—laptop, desktop, or server—has a radio Network
Interface Card (NIC). APs are essentially hubs, outfitted with a radio transceiver,
Ethernet uplink, and 802.1d bridging software. Wireless stations transmit
to an AP over a shared channel, carved out of the unlicensed 2.4 GHz band.

Approved in 1997, the original IEEE 802.11 standard uses the 2.4 GHz
band to provide shared bandwidth at a maximum rate of 1 to 2 Mbps. In
1999, the IEEE approved the 802.11b High Rate (Wi-Fi) amendment, increasing
the rate to 11 Mbps. Together, these standards specify WLAN Physical (PHY),
Media Access Control (MAC), and Logical Link Control (LLC) layers for
fixed wireless broadband access and WLANs.

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