Wireless spec making (air) waves
- By Paul Korzeniowski
- Jun 03, 2002
Daily, about 60 employees at the Social Security Administration in Baltimore walk through a warehouse, pull forms, pamphlets and publications from various shelves, and ship the materials to private organizations, businesses and 3,800 agency offices.
"Manually entering data about which forms were sent to what offices was an inefficient, time-consuming process," said Gary Orem, a program manager at SSA. But by outfitting employees with handheld scanners and deploying wireless local-area networks from Intermec Technologies Corp., the agency cut the time it took to fulfill these orders from 45 days to one or two, eliminated a three-week backlog and reduced SSA's operating expenses by $1 million a year.
The agency represents the typical government wireless LAN user. Wireless LANs have made their way into select applications, such as those used in warehouses, military field units and emergency response systems, "where there is a need to collect information but traditional wiring is impractical," said David Krebs, group manager at Venture Development Corp. His market research firm found that federal use of wireless LANs increased by 8 percent in 2001.
After the 802.11b wireless LAN standard was ratified in late 1999, companies began releasing compliant products, sparking the increase in sales. New versions of the standard are expected to attract an even broader user base.
Previously, vendors relied on proprietary techniques to move information via wireless LANs, which operated at
2 megabits/sec. The 802.11b standard increased that speed to 11 megabits/sec and enabled vendors to price their products more competitively because they could produce one item for many customers rather than distinct ones for each.
Users can now mix and match vendors' products, and they have plenty of choices from companies such as Colubris Networks Inc., Intermec, Proxim Inc. and Symbol Technologies Inc. In addition, just about every major networking company offers wireless LAN products, including 3Com Corp., Alcatel, Avaya Inc., Cisco Systems Inc., Enterasys Networks Inc. and Nortel Networks Ltd.
The increased competition has also driven down pricing. "Three years ago, a wireless adapter cost a few hundred dollars, compared to $80 to $90 today, and a network access point was priced at more than $1,000. Now, it is about $170," said Greg Collins, a director at Dell'Oro Group, a market research firm.
With prices falling, government agencies are finding new uses for the technology. For instance, Army officials at Fort McPherson, Ga., who must meet the never-ending challenge of ensuring that their facility is secure, have begun testing a system that places wireless LAN adapters in vehicles. As a vehicle approaches an entry point, it transmits information to a server, which then determines whether to open a gate and allow entry.
"We are still experimenting [with] placing transmitters on each vehicle to ensure that the data is received," said Hugh Wiley, deputy director of public safety at the base. Officials plan to complete a pilot test of the system this summer.
Although interest in 802.11b networks is growing, the technology has yet to move beyond a niche audience for a variety of reasons. For starters, many agencies find justifying wireless LAN deployments difficult, if not impossible.
Wireless systems cost more and deliver less bandwidth than terrestrial LANs. In addition, Ethernet-wired adapters, which support speeds from
10 megabits/sec to 100 megabits/sec, are often bundled with new PCs. The top speed for a wireless adapter is 11 megabits/sec, although vendors are putting the finishing touches on a
54 megabits/sec standard. Prices range from $70 to $100 per adapter. Pricing for wired Ethernet LAN access points is about $50 per port, while wireless links cost about four times as much.
Also, wireless connections can be more difficult to deploy than their wired brethren. A wireless link consists of a sending component, which is an adapter that fits into a laptop slot, and a receiving device, called an access point, which functions like an Ethernet switch and collects information from a number of systems. Its inbound connection resembles a cellular antenna, capturing radio waves transmitted within a certain distance, and its outbound link is a wired line that connects users to a wired enterprise network.
A wireless LAN user does not need unimpaired line of sight from the adapter to the access point, because transmissions usually can penetrate walls and other nonmetal barriers. However, wireless LAN access points have to be stationed close to one another so transmissions do not drop as users move from place to place. Consequently, a network technician has to decide how many users an access point can support.
It is simple to make such determinations with wired links, but wireless connections are not as straightforward because the number of users logging on to an access point constantly changes.
In theory, as many as 50 wireless terminals can share an access point; however, the more users tap into a point, the more likely that throughput problems will arise. Also, shipping large files, such as video clips, will slow performance. In practice, companies have found that 15 to 20 users can work with each access point.
The network administrator also has to decide how far users can be from the access points. An access point can reach users up to 1,000 feet away, but once again, that depends on an agency's network traffic pattern.
Because each deployment is unique, positioning must be done on a case-by-case basis. Agencies often need to experiment with a couple of different configurations before they find the one that works best.
Better Security Needed
Security is a top concern for many government agencies. Unfortunately, "we found [that] a number of agencies have implemented insecure wireless LANs," said Scott Hemmig, director of e-government solutions at Avaya. Once an agency deploys a wireless network, breaking into it can be a simple as connecting another wireless PC to the LAN.
Encryption helps agencies protect information, but 802.11b's encryption techniques, dubbed Wired Equivalent Privacy (WEP), are limited. The specification, which complies with federal encryption export rules that existed when development of the standard began in 1997, limits public encryption keys to 40 bits.
"Hackers can download free programs from the Internet that break WEP security functions," said John Dow, vice president of marketing and corporate development at Fortress Technologies Inc.
To address the problem, the Institute of Electrical and Electronics Engineers Inc. is developing the 802.11i standard. It uses the Extensible Authentication Protocol, which supports 128-bit encryption and a variety of authentication processes. Vendors expect the standard to be completed by the end of the year and plan to begin shipping compliant products next year.
In the meantime, suppliers have relied on proprietary techniques to plug security holes. "The 802.11b security glitches definitely slowed the momentum we saw in wireless LAN adoption," said Dan Shell, consulting engineer at Cisco.
New uses for the technology have been fueling that momentum. Increasingly, telecommuters and small office users are coupling Digital Subscriber Line services and wireless LANs to support integrated voice and data services, said Ken Haase, director of product marketing at Proxim.
The Sept. 11 terrorist attacks also spurred interest in 802.11b networks for disaster recovery applications. "After Sept. 11, many agencies understood the need for more flexible communications systems, a term that fits wireless LANs," said Avaya's Hemmig.
So despite the deployment and security concerns, the technology continues to take root. "Wireless LANs are not a technology where there has been a lot of talk and no action," said Venture Development's Krebs. "There has been a steady increase in the number of organizations implementing the technology, and I expect that to continue during the next few years."
Korzeniowski is a freelance writer in Sudbury, Mass., who specializes in technology issues. He can be reached at firstname.lastname@example.org.