New in Wireless...
- By Wendy Chretien
- 01/31/05
A fast review of what’s next in higher ed wireless networking technologies.
If you’re involved with the care and construction
of campus networks, you know that keeping up with developments in the wireless
world is nearly a full-time job. But what if you cannot devote about 40 hours
each week to keeping informed? To the rescue: A summary of some of the emerging
changes and issues follows.
Ubiquity
Wireless LANs on most campuses consist of islands of
coverage. Students, however, now have begun to expect wireless data coverage to
be just as available as coverage for their mobile phones—in some cases, even off
campus. You may wish to compare your institution to Intel Corporation’s top 100
list of “Most
Unwired Colleges.” While 100 percent campuswide coverage isn’t yet
widespread, it is out there: For example, Case Western Reserve University (OH) features the
world’s largest, free, public wireless network, covering its 90-acre campus with
more than 1,315 access points. You can expect ubiquitous wireless, or at least
the expectation of it, to head your way soon.
Interference
In an unlicensed arena like Wi-Fi, it’s too easy for a
student or staffer to set up a new wireless network without understanding or
dealing with the potential interference to existing networks. By now, the
controversy generated in September 2004 at the University of Texas at Dallas
(about restricting students’ use of Wi-Fi in dorms, due to wireless
interference) has subsided, but that’s because the administration backed down
from its initial stance. UT’s proposal to prohibit the use of private Wi-Fi
networks fizzled due to protests that only the FCC has jurisdiction over the
interference of radio signals. In the long run, most higher ed institutions will
need to create policies dealing with interference and security. One option:
Apply existing Acceptable Use Policy (AUP) boundaries to prevent harm to the
university’s network environment.
Security
The first recent development in
security—the new IEEE 802.11i standard—was ratified in June 2004 and is
available in some products now. The biggest change is support for the AES
encryption standard, which although requiring new hardware in access points, can
greatly enhance the privacy of wireless communications. Products that meet the
802.11i standard should be labeled as WPA2-compliant.
Another development in this area is the use of
centralized “wireless switches” to configure security settings and enforce
policies across the entire wireless network, from one point. Aruba (www.arubanetworks.com) and Airespace (www.airespace.com) are the market leaders, but the big
networking vendors are moving in. One instance is the Cisco Systems (
www.cisco.com)
purchase of AirDefense in October 2004, to strengthen its wireless security
story (the Airespace buyout is next). New products should be available in March
that incorporate the RF monitoring capabilities boasted by AirDefense. Key
features include detection of “rogue” access points, protection against
unauthorized intrusions, and the ability to track a wireless network’s overall
“health.”
Remember, security can be imposed at several layers in
the OSI model, and a multilayer defense is more effective than any single
method. (American
University in Washington, DC uses a combo of encryption keys; unique
Service Set Identifier, or SSID, names; and required registration to a
university computer account.) If your campus has Remote Authentication Dial-In
User Services (RADIUS) authentication in place, be sure to utilize it for your
wireless LANs, too.
Voice Over the Wireless LAN
(Wireless VoIP)
For those who understand just how different wireless is
from wired networking, wireless VoIP is a somewhat frightening prospect. Why?
Because to achieve good voice quality requires very consistent network
conditions, and it’s tough to design a wireless network that meets those
stringent requirements. Dartmouth College
(NH) is piloting students’ use of softphones (a program on the computer that
allows it to be used like a phone; a headset is highly recommended) over the
campus network, including the wireless network. The college is testing a
combination of equipment including such from Cisco Systems. Another manufacturer
working in this area is Extreme Networks (www.extremenetworks.com),
which is supporting voice over wireless by implementing the SpectraLink Voice
Priority Protocol and Inter-Access Point Protocol in its Layer 3 switches.
Handhelds on the WLAN
Remember the softphones at Dartmouth?
That software is also available on some personal digital assistants (PDAs),
permitting users to make voice calls over the wireless LAN via handheld devices.
This will be an added boon to many: Wireless PDAs have really taken off in the
university healthcare environment where practitioners use the devices to access
patient records, record vital signs, and review medication orders. Now, they’ll
be able to communicate, too.
Other Trends…and You
Watch for increases in wireless
throughput to 100 Mbps via 802.11n (planned to be ratified in 2006), with
pre-standard implementations as early as this summer. Another IEEE standard in
the making is 802.11e, which will specify quality of service (QoS). This
standard is expected to be ratified by mid-year. However, packet prioritization
or Wi-Fi Multimedia (WMM) is already here.
Also coming soon are phones that can
use both traditional cell/PCS and Wi-Fi. The first of these have come to market,
but are not yet widely available.
As for the trends in general, and
what action you should take: Frankly, it isn’t a question of whether, but when
these trends will affect your institution. Prepare yourself now for the future
of wireless on your campus by researching and piloting some of these new
technologies; in short, work now to get those policies in place.