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A
wireless network or
Wireless Local Area Network (WLAN) serves the
same purpose as a wired one — to link a group of
computers. Because
"wireless" doesn't require costly wiring, the main benefit is that
it's generally easier, faster and cheaper to set up.
By comparison, creating a network by pulling wires throughout the
walls and ceilings of an office can be labor-intensive and thus
expensive. But even when you have a wired network already in
place, a wireless network can be a cost-effective way to expand or
augment it. In fact, there's really no such thing as a purely wireless
network, because most link back to a wired network at some point.
The Basics
Wireless networks operate using radio frequency (RF)
technology, a frequency within the electromagnetic spectrum
associated with radio wave propagation. When an RF current is
supplied to an antenna, an electromagnetic field is created that
then is able to propagate through space.
The cornerstone of a wireless network is a device known as an
access
point (AP). The primary job of an access point is to broadcast
a wireless signal that computers can detect and "tune" into. Since wireless networks are usually connected to wired ones, an access point also often serves as a link to the resources available on the a wired network, such as an Internet connection.
In order to connect to an access point and join a wireless network,
computers must be equipped with wireless
network adapters. These are often built right into the computer,
but if not, just about any computer or notebook can be made
wireless-capable through the use of an add-on
adapter plugged into an empty
expansion slot,
USB port, or in the case of notebooks, a
PC Card slot. |
Key Terms To
Understanding Wireless Networks:
Related Articles
on Webopedia:
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Wireless Technology Standards
Because there are multiple technology standards for wireless networking,
it pays to do your homework before buying any equipment. The most common
wireless technology
standards include the following:
- 802.11b: The first widely used wireless networking technology, known as 802.11b (more
commonly called Wi-Fi), first debuted almost a decade ago, but is still in
use.
- 802.11g: In 2003, a follow-on version called 802.11g appeared offering greater
performance (that is, speed and range) and
remains today's most common wireless networking technology.
- 802.11n:
Another improved standard called 802.11n is currently under development and
is scheduled to be complete in 2009. But even though the 802.11n standard
has yet to be finalized, you can still buy products based on the draft
802.11n standard, which you will be able to upgrade later to the final
standard.
All of the Wi-Fi variants (802.11b, g and n products) use the same 2.4
GHz radio frequency, and as a result are designed to be compatible with each
other, so you can usually use devices based on the different standards
within the same wireless network. The catch is that doing so often requires
special configuration to accommodate the earlier devices, which in turn can
reduce the overall performance of the network.
In an ideal scenario you.ll want all your wireless devices.the access point
and all wireless-capable computers.to be using the same technology standard
and to be from the same vendor whenever possible.
Speed & Range
When you buy a piece of wireless network hardware, it will often quote
performance figures (i.e., how fast it can transmit data) based on the type
of wireless networking standard it uses, plus any added technological
enhancements. In truth, these performance figures are almost always wildly optimistic.
While the official speeds of
802.11b,
802.11g, and
802.11n networks are
11, 54, and 270 megabits per second (Mbps) respectively, these figures
represent a scenario that.s simply not attainable in the real world.
As a general rule, you should assume that in a best-case scenario you.ll get
roughly one-third of the advertised performance.
It's also worth noting that a wireless network is by definition a shared
network, so the more computers you have connected to a wireless access point
the less data each will be able to send and receive. Just as a wireless
network's speed can vary greatly, so too can the range. For example, 802.11b
and g officially work over a distance of up to 328 feet indoors or 1,312
feet outdoors, but the key term there is "up to". Chances are you won't see
anywhere close to those numbers.
As you might expect, the closer you are to an access point, the stronger the
signal and the faster the connection speed. The range and speed you get out
of wireless network will also depend on the kind of environment in which it
operates. And that brings us to the subject of interference.
Interference
Interference is an issue with any form of radio communication, and a
wireless network is no exception. The potential for interference is
especially great indoors, where different types of building materials
(concrete, wood, drywall, metal, glass and so on) can absorb or reflect radio
waves, affecting the strength and consistency of a wireless network's
signal. Similarly, devices like microwave ovens and some cordless phones can
cause interference because they operate in the same 2.4 frequency range as
802.11b/g/n networks.
You can't avoid interference entirely, but in most cases it's not
significant enough to affect the usability of the network. When it does, you
can usually minimize the interference by relocating wireless networking
hardware or using specialized
antennas.
Data Security
In the same way that all you need to pick up a local radio
station is a radio, all anyone needs to detect a wireless network within
nearby range is a wireless-equipped computer.
There's no way to selectively hide the presence of your network from
strangers, but you can prevent unauthorized people from connecting to it,
and you can protect the data traveling across the network from prying eyes.
By turning on a wireless network's encryption feature, you can scramble the
data and control access to the network.
Wireless network hardware supports several standard encryption schemes, but
the most common are Wired Equivalent Privacy (WEP),
Wi-Fi Protected
Access (WPA), and
Wi-Fi Protected Access 2 (WPA2). WEP is the oldest and least secure method and
should be avoided. WPA and WPA2 are good choices, but provide better
protection when you use longer and more complex passwords (all devices on a
wireless network must use the same kind of encryption and be configured with
the same password).
Unless you intend to provide public access to your wireless network
— and put your business data or your own personal data at risk — you
should consider encryption mandatory.
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DID YOU KNOW...
ad-hoc mode is an 802.11 networking framework in which
devices or stations communicate directly with each other,
without the use of an access point (AP). Ad-hoc mode is also
referred to as peer-to-peer mode or an Independent Basic Service
Set (IBSS). Ad-hoc mode is useful for establishing a network
where wireless infrastructure does not exist or where services
are not required. |
Adapted article courtesy of
SmallBusinessComputing.com.
You can read the
full version here.
Last updated: April 11, 2008
Did You Know... The Differences Between Hubs, Switches and Routers?
Ever wonder what the difference is among these boxes? The functions of the
three devices are all quite different from one another, even if at times they
are all integrated into a single device. Which one do you use when? Let's take a
look...
PracticallyNetworked.com
PracticallyNetworked.com provides
easy-to-understand help for small-network builders. The site contains how-to
information for setting up and debugging home-office and small-business
networks. Users can also find extensive troubleshooting information, tips on
getting applications to work through firewalls, product reviews on network
hardware and software, and more.
The Differences Between WEP and WPA
When protecting data send via wireless, security and protection is offered
through encryption schemes that come with your wireless hardware you can enable.
Wi-Fi
Planet
802.11 news, commentary and information.
Minimizing
802.11 Interference Issues
RF interference will continue to plague current
and future 802.11b implementations unless an adequate site survey is conducted -
preferably prior to actual network installation.
Did You Know...All About Broadband/ICS Routers
Not all routers are created equal since their job will differ slightly from
network to network. Additionally, you may look at a piece of hardware and not
even realize it is a router. What defines a router is not its shape, color, size
or manufacturer, but its job function of routing data packets between computers.
SmallBusinessComputing.com
Provides technology solutions for small
business owners, hardware/software reviews, webmaster resources and news. |
