An introduction to wireless networking
By Eric Leland
Wireless networking products have become more popular in
the last few years due to an increase in competition among
manufacturers and the emergence of a more dominant wireless
technology standard. This report looks at the benefits and
drawbacks of wireless networking and provides further resources
for research into wireless products.
Definition: Wireless Networking
Wireless networking refers to hardware and software combinations
that enable two or more appliances to share data with each
other without direct cable connections. Thus, in its widest
sense, wireless networking includes cell and satellite phones,
pagers, two-way radios, wireless LANs and modems, and Global
Positioning Systems (GPS).
Definition: Wireless LAN
Wireless LANs enable client computers and the server to
communicate with one another without direct cable connections.
Generally, a wireless LAN is connected to an existing wired
LAN, although they can exist without a wired LAN (in this
case, users will only be able to communicate with other users
on the same subnet).
Components of a Wireless LAN
Necessary components include an Access Point, Client LAN
adaptors and the wired LAN. The Access Point is a device that
translates between the wired LAN and the wireless LAN. The
Client LAN Adaptors are PC cards, PCI or ISA boards that plug
into laptop or desktop computers equipped with radio transceivers
to communicate with the Access point. Other components to
a wireless LAN can include Extension Points and Directional
Antennas. Extension Points are devices similar to the Access
Point, but not connected to the wired LAN. Extension points
serve to extend the range of the wireless network by relaying
signals from client computers to the Access point. Directional
Antennas serve to connect wireless networks located at a greater
distance from one another. Each network would have an antenna
targeted at each other (known as a "line of site" connection).
Manufacturers have adopted many competing standards for
implementing wireless communication. Interoperability between
different communications standards is currently not available.
It is important to evaluate, with any wireless LAN networking
system, the technology it uses, the features it provides and
the industry support it has. Below are common standards available:
How a Wireless LAN works
In a typical wireless LAN configuration, the Access Point
connects to the wired network from a fixed location using
standard cabling. The access point receives and transmits
data between the wireless LAN and the wired network infrastructure.
A single access point can support a small group of users and
can function within a range of less than one hundred to several
hundred feet. End users access the wireless LAN through the
wireless-LAN adapters installed in their computers.
Benefits of Wireless LANs
Cost: Wireless LANs can cost less to implement than
wired LANs, especially in situations where implementing a
wired LAN requires extensive labor and materials to install
the wiring and drops. For environments that are difficult
to wire (such as schools or temporary spaces) a wireless network
can be more cost-effective in the long run than a wired one.
Simple/flexible to Install: Wireless LANs eliminate
the time needed with wired LANs for laying and pulling wires,
and can reach places that cannot be reached by wires. Portability:
Wireless LAN systems can move physical locations much easier
than wired LANs, reducing total cost of ownership for organizations
that are on the move.
Mobility: Wireless LAN systems can provide LAN users
with access to network information anywhere in their organization.
Scalability: Wireless LAN systems can be configured
for small offices and large, with peer-to-peer systems or
large established LANs, specific to the localized need of
a workgroup or across the whole enterprise. Wireless LAN systems
grow easily with the need by adding more access points, client
LAN adaptors and extension points. Wireless can be a good
solution if you need to connect several buildings without
installing a wired connection. Wireless LAN bridges can extend
LANs that are typically one to five miles apart. These wireless
bridges span multiple-building LANs without incurring the
monthly costs of a T1 or higher speed lines.
Drawbacks of Wireless LANs
Cost: In environments with installed wiring or less
demanding wiring needs, the up front costs of adopting a wireless
LAN system can be more expensive than with wired LANs.
Interoperability: There are several competing technologies
used by wireless LAN vendors to communicate data between hardware,
with no ability for communication directly between systems
using these different standards.
Interference: Most of the wireless devices today operate
on 2.4-GHz radio bands, which are also used by cordless phones
and most microwave ovens. The potential for interference when
used near other devices sharing the same frequency band.
Speed: Most commonly used wireless LAN products are
rated for a maximum 11Mbps throughput, and in practice see
speeds about 80% less than this - some wireless LAN products
are rated for speeds much less than this (HomeRF systems for
example). Still quite speedy for most network needs and for
broadband Internet sharing, but for larger offices with high
network traffic and demands for speed, this should be taken
Wireless LAN Products
Simple wireless LAN systems provide an Access Point that
is plug-and-play when connected to an existing wired network.
They may or may not include client LAN adaptors. More advanced
solutions function as stand-alone networking systems that
often provide cable/dsl router, switch, DHCP and firewall
technology together with an Access Point. As of this report,
prices for Access Points range from $250 to $1500 each, and
client LAN adaptors cost from $80-$200 each. When networking
Macintosh systems, it is important to consider whether the
product comes with macintosh drivers for the Access Point
and the client LAN adaptors, and if there is a Macintosh version
of the supporting administration software. If you've decided
that a wireless LAN is the right networking solution for your
organization, here are a few products that we recommend...
For the small office, D-link offers a wireless Access Point
using the 802.11b specification plus two USB client LAN adaptors
for $500 (kit with two PC cards for laptops costs $450). This
unit has DHCP built in and can be used with or without an
existing wired network. D-Link also offers an inexpensive
stand alone Access Point (DI-713) for $200. PC only. See http://www.dlink.com
for more details.
For larger systems, Orinoco AP-1000 offers a wireless Access
Point with an array of features, including the ability to
upgrade radio technology by swapping in new PC cards - thus
if Orinoco decides to adopt a new radio standard, the Access
Point can still be used. Also has load balancing, support
for voice transmission, uses 802.11b standard, supports wired
and fully wireless setups and more. Access Point costs around
$900 and each client LAN adaptor costs around $150. Mac and
PC. See http://wavelan.com/template.html?section=m58&page=103&envelope=94
for more details.
Apple Airport offers a wireless solution geared primarily
toward Macintosh networks comparable to the D-link option
($300 for each access point, $100 for each LAN adaptor). One
unique feature of the Airport is that HP makes a device capable
of wirelessly sharing printers with the Airport Access Point
($300). Thus the printer does not have to be connected via
wires to a server computer. Check out http://www.apple.com/airport/specs.html
for information on the Airport.
Comparison of Several Wireless LAN Products (May 2001) http://www.pcworld.com/reviews/article/0,aid,50415,pg,8,00.asp
Reviews of Wireless LAN products (Feb 2001) http://www.zdnet.com/products/stories/reviews/0,4161,2685770,00.html
Apple Airport Access Point (popular Mac wireless networking
TechRepublic: Wireless LAN Articles and discussion http://www.techrepublic.com/article.jhtml?src=search&id=r00720010330bla01.htm
Good introduction on how wireless LANs function and their
Gartner Wireless LAN whitepaper (January 2001) http://www.techrepublic.com/download_item.jhtml?id=dr00620000616ang13.htm
Gartner Bluetooth whitepaper (August 2000) http://www.techrepublic.com/download_item.jhtml?src=search&id=dr00520000817ggr01.htm
HomeRF Standard Homepage
Universal Client Wireless LAN Adaptors