New Momentum For Wireless LANs

News flash: 2000 will be the year of the wireless LAN.

If you're a network manager, you're probably groaning, having heard this declaration before. But industry interoperability testing is lending new credibility to the claim that wireless LANs finally will be ready for enterprise-class applications, enabling office workers to take Internet connectivity with them into conference rooms, colleagues' cubicles, even into the lunchroom.

Still, several kinks must be worked out if wireless LAN products from different vendors are to work together.

The industry's first 802.11 certification tests, results of which were released this week by the Wireless LAN Interoperability Forum, reveal problems with coordinating access points for roaming.

The 802.11 standard itself doesn't specify a hand-off mechanism to allow clients to roam from one access point--a physical unit usually placed in the ceiling to conduct radio frequencies--to another access point. Vendors have implemented their own solutions.

Lynn Chroust, product marketing director for wireless LAN vendor Proxim Inc., a test participant, said the forum's roaming test was the most advanced undertaken to date. “They put different vendors' access points on the infrastructure, and then tried to have clients from different vendors roam around,” Chroust said. However, according to Chroust, there was very little communication between the access points, which were supposed to work together, forwarding traffic to one another.

Roaming is a key concern of Internet environment managers, because, as users move from one access point to another within offices, they could lose their connections to the Net and have to re-establish them at the next access point. “Routing IP is a challenge. IP addresses just aren't used to moving around,” said Bill Huhn, vice president of marketing at Intermec Technologies Corp., a wireless LAN vendor and test participant.

Wireless network management and security also must be improved, test participants said.

Huhn said few vendors have gotten to the point of providing basic diagnostics to help IT managers pinpoint problems on their wireless networks--critical because of the fluid nature of these environments. Roaming, meantime, presents a security challenge. Encryption is built into most wireless LAN products, but “the industry needs to work on the ability to authenticate users moving from one point to another,” Huhn said.

Casey Sterling, systems administrator for Southern Company Energy Marketing, had a different security problem with his early wireless network: Anyone using the same wireless adapter card as Southern could join the network unencumbered.

“All they'd have to do was plug into the network, and the network would automatically assign them a DHCP address,” Sterling said. That bug, however, was fixed by the vendor, Proxim.

On a positive note, 802.11 wireless vendors are showing they're willing to participate in certification testing to identify such problems, and to reassure wireless LAN adopters that they won't be locked into one vendor.

As Chroust pointed out, wireless LANs are still in their infancy, relative to wired Ethernet.

“The Ethernet we know is not how it started out,” she said. “There were years and years of interoperability testing. Wireless networking is not mainstream for most IT managers yet. It's pretty mysterious.”

That is one reason the Wireless LAN Interoperability Forum set out to test 802.11 products: to increase their visibility. (The University of New Hampshire's Interoperability Laboratory did the actual testing.)

Another reason for the testing is that the 802.11 spec is about 500 pages long, leaving plenty of room for interpretation by equipment vendors. The forum planned certification testing to ensure that vendors are following the letter of the standard.

Once issues such as roaming are ironed out, wireless internetworking could move beyond its current niche applications in distribution centers, retail and the medical field.

Enterprise applications involve constant connectivity for employees on the move within their buildings. Picture the CEO giving a speech in a company auditorium and employees accessing the presentation on their laptops, or employees in a conference room meeting accessing e-mail or various Web sites.

At ISP D&E Communications, a wireless network at headquarters has greatly enhanced productivity, said Philip Theis, director of information technologies. When directors from various branches get together for meetings, each is offered a wireless laptop or palmtop loaded with a RangeLAN2 wireless adapter card from Proxim. RangeLAN2 access points are positioned on shelves above the ceiling in conference rooms on each of six floors in the building.

The meeting participants have instant access to updated information on the company Web site, as well as to recent e-mails that may provide information useful for the meeting.

“We encourage our employees to store all of their data on the network,” Theis said. “And all applications are stored on the network, as well, instead of being installed on individual machines.”

Theis also noted that meeting participants can get important corporate updates via e-mail rather than disruptive pagers. Data travels over the wireless network at 1.6 Mbps.

Southern Company Energy Marketing, which trades energy as a commodity, has another e-mail-related use for wireless networking.

Before Sterling equipped his help-desk staffers with Hewlett-Packard's Jornada handheld computers loaded with Proxim's wireless LAN card, they would spend half the day running to their offices to check for e-mail from clients needing help, and then running back to the trading floor to assist those individuals. Now staffers essentially carry their office with them, and receive e-mail help requests on the fly.