Early adopters of wireless technology were in vertical markets. These users
were more concerned with mobility than with standards or throughput. Users
today are moving into more horizontal markets where mobility may be less of a
concern than interoperability and throughput. With the 802.11a and 802.11b WLAN
products, mobility and roaming do not have to be sacrificed to gain throughput
and interoperability. However, choosing the correct WLAN technology is very
important and depends on the application and infrastructure
.
The
primary applications for wireless networking are as follows:
- First is the small office, home office (SOHO) user. Generally, within this
application, multiple PCs communicate either via the AP or directly
card-to-card without the use of a hub.
- Second, mobile workers within an enterprise who do not have a stationary
desk within their corporate office. Mobile workers could also require
connectivity within an open-air environment such as a conference room. In
general, mobile workers are in occupations such as education, retail,
warehousing, and healthcare.
- Last, the connection of two or more buildings to form site-to-site
connections to link their networks together. It could also be mobile workers
requiring access to their corporate network from outside their buildings, such
as from a parking lot.
The infrastructure consists of a variety of hardware. In some cases,
multiple products are required to complete the entire infrastructure. The
various components include the following:

- Bridges – Used to connect LANs together in a site-to-site application
- AP – Serves as a connection point between a wired and wireless network
- Antenna – Transmits signals between the wireless client and the bridge or
AP
- Network Interface Card (NIC) – Resides with the client and provides a
connection point to the AP
- External NIC – Provides an Ethernet connection with a wireless transmitter
for a device that already has an Ethernet NIC installed
- External hub – Provides multiple Ethernet connections in the form of a hub
with a wireless transmitter for devices that already have Ethernet NICs
installed
- Third Party – Devices such as bar code scanners, telephones, and personnel
digital assistants (PDAs), which can connect to the 802.11 wireless
infrastructure