For any enterprise considering a wireless implementation, a good network architect is an absolute
must, preferably an architect who understands security issues associated with enterprise wireless
networks. It will save time and expense down the road to have a clear understanding of your
goals and capabilities, and the expected returns from the investment, before spending a penny.
The first critical issue is whether you need a local area network technology to support
internal users or a wide area network solution to support a workforce that is out in
the field. The next big issue is how to secure the network once it is up and running.
(If you're new to wireless, please read our
Wireless Overview.)
Wireless Local Area Network (WLAN)
If you want to offer mobility to employees who move within an office building
or complex, then a local area network, or a metropolitan/campus area network
if your facilities are expansive, is the most logical choice. The three major
IEEE WLAN standards
are 802.11b WiFi,
802.11a, and
802.11g. There are a number
of tradeoffs with each that should factor into your technology choice:
- Transfer speed. 802.11b WiFi provides transfer speeds
up to 11 megabits per second, whereas 802.11a provides transfer speeds
up to 54 megabits per second. The new IEEE standard, 802.11g, also supports
a transmission speed of 54 megabits per second
- Range. 802.11b WiFi has a range of up to 100 meter indoors
and 300 meters outdoors, but 802.11a has a shorter range than WiFi,
requiring more access points. 802.11g has the same range as WiFi.
- Interference. WiFi suffers from interference from other
2.4 GHz devices like microwave ovens, but 802.11a does not since it operates
in the 5 GHz range. 802.11g operates in the 2.4 GHz band, so it does have
the same interference problems as WiFi.
- Compatibility. 802.11a is not backwards compatible with WiFi,
requiring two different access devices if you need to support both WiFi and
802.11a devices in the same space. 802.11g is backwards compatible with both
802.11a and WiFi.
The bottom line is that 802.11g offers the speed of 802.11a and the range of WiFi.
Wireless Wide Area Networks (WWAN)
If your requirement is to support mobile employees outside the
four walls of the office, then a wide area wireless solution is more appropriate.
WWAN links
are generally offered by telecom carriers, such as Sprint and AT&T.
Like any other wireless plan for voice, this decision comes down to coverage area,
cost, and device requirements. The major downside to the Wireless WANs is the
transfer speed. The technology is still trundling along at about the same speed
as a 56K modem. Wireless broadband services are still being developed that could
bump that speed up to 2-4 megabits per second.
Wireless Security
Security is probably the number one concern
expressed by IT managers considering a
wireless implementation. Each technology introduces different
wireless security risks,
so it's well worth doing some research to understand those risks up front.
The main known wireless security risks with WLANs include:
- Insertion attacks. Insertion attacks occur when an unauthorized device
is placed on the wireless network without going through a security process and review.
- Intercepting and monitoring wireless traffic. An attacker can
sniff and capture legitimate traffic on a wireless network. Wireless sniffing requires
the attacker to typically be within range of the wireless traffic.
- Misconfiguration. Generally, factory settings for wireless devices
are set to the least secure mode possible, leaving proper security configuration to
the administrator.
- Jamming. The principles of a denial of service attack for a wired
network can be applied to wireless traffic as well. Legitimate traffic gets
jammed because illegitimate traffic overwhelms the frequencies.
- Client-to-client attacks. Two wireless clients can talk directly
to each other, bypassing the base station. Because of this, each client must protect
itself from other clients.
For more information on choosing the right wireless solution for your company,
read our Wireless Overview.
Go to Bitpipe Research Guide: Wireless.
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