Wireless local area networks
(WLANs) are small-scale wireless networks with an operational
distance of a few hundred feet. WiFi is the most prevalent
form of WLAN technology, which encompasses a host of
specifications within in the 802.11 family. The specification
uses a spread spectrum technique of frequency hopping
to increase security, see security below. 802.11a is
an extension to 802.11 that provides 54Mbps to wireless
LANs in the 5Ghz band. 802.11b or WiFi, provides 11Mbps
transmission in the 2.4Ghz band. 802.11g provide 20+
Mbps in the 2.4Ghz band. While WiFi technology has to
compete against WANs, GPRS, 3G etc its fast data speeds
and relatively cheap implementation costs have made
it a popular choice across many market sectors.
Accessibility
Wireless corporate mobile connectivity
is becoming well established for Internet access and
applications on the private LAN. It is ideally placed
to serve the health sector for access to patient records
and to allow public access to the Internet. Other
public access eg airports, libraries and hotels are
becoming available although there are concerns on
the cost effectiveness of free access and this may
change in the future.
Applications
Many appliances, like laptops,
mobiles phones, PDAs, now have 802.11 functionally
built in or available as optional additions. This
move towards lighter portable devices is moving the
market for mobile users to access their email and
databases easily and from anywhere. Its appeal is
across many sectors of industries for a variety of
uses:
- Warehouse inventory tracking
- Patient care records;
- Real-time information sharing;
- Extending broadband limitation
reach;
- Reducing IT costs;
- Security and surveillance;
- Convergence of voice and data
to public hotspots.
Return
on Investment
For organisations considering
implementing WLAN infrastructures a free benefits
calculator tool is available from: http://www.wi-fi.org/OpenSection/WLAN_Calculator.asp
Point-to-Point
and Last Mile Access
WLANs are not just for mobile users.
Interconnectivity between buildings on an enterprise
campus, hospital or educational establishment has
shown that WLANs can provide dedicated bandwidth and
offer alternatives for DSL, E1/T1 or lease line connections.
Payback for using point-point or point-to-multipoint
solutions can show a return on investment over traditional
lines within 12 months.
WLANs are insecure. The spread
spectrum techniques, developed in the war, are nearly
impossible to break unless the 'spreading codes' are
known. The 802.11 publicly define those spreading codes,
which obliterates its inherent security. Hackers can
sniff SSIDs (Service Set Identifiers) to attach rogue
access points (AP) by using easily obtained analysis
tools like Netstumbler or AiroPeek. Although SSIDs can
be turn off by administrators they can still be found
in the frames that are associated with an AP.
With 802.11 networks you can enable Wired Equivalent
Privacy (WEP) to provide elementary encryption for sensitive
data. However, monitoring an active network for less
than a day can easily expose the keys required to decrypt
the traffic.
WLANs can be made to be secure using strong encryption
techniques and restricting user access with two-factor
token authentication at access login to authentication
servers like Defender.
Link
to Products and Wireless Networks
For
further information on implementing practical and secure
WLANs then please contact our office.
