The number of wireless LAN users in North America is poised to grow more than sevenfold in the next four years, market-research firm Gartner says.

Businesses should respond to the wireless boom's opportunities by rolling out the low end of Wireless Fidelity hardware now, Gartner's analysts said Thursday at its conference in San Diego. But they should be ready to deploy higher-bandwidth gear to their mobile workers by the end of next year.

The number of wireless LAN users, expected to number 4.2 million this year, will increase to more than 31 million by 2007, Gartner's study says. However, the increase will lag behind the climb in the number of "hot spots"--zones for wireless access to the Internet and E-mail via notebooks, handhelds, and the newest generation of data-ready mobile phones.

"As more and more wireless applications are built requiring broadband connections, the possibility of more than 100,000 'hot spots' within the next five years is an innovation that can't come too soon" for providers, says Ken Dulaney, a VP and research director for Gartner. His findings point to a stall in hot-spot provider profitability until a larger number of users are armed with wireless LAN capabilities.

For the moment, deploying 802.11b-compliant wireless gear is the smart move for businesses, he says. The low end of wireless accessibility, 802.11b delivers a relatively narrow 11-Mbps pipeline to the Internet. "In most cases, businesses will be satisfied with 802.11b performance, and 802.11b will be the technology of choice for hot-spot frequenters," Dulaney says.

Two other standards, 802.11a and 802.11g, offer bigger bandwidth--up to 54 Mbps--and eventually will supplant Wi-Fi, according to Gartner. The former uses a different radio frequency than 802.11b (5 GHz as opposed to 2.4 GHz), but it's the only approved fast-access wireless standard. Although hardware supporting 802.11g, which, like 802.11b, sends its signals at the 2.4-GHz frequency, has appeared, the standard is still in flux and not scheduled to be set until later this year.

In fact, earlier this month, Gartner recommended that large companies steer clear of 802.11g until the standard is certified by the nonprofit Wi-Fi Alliance. Gartner urged companies to wait until the fourth quarter of 2003, when 802.11g-certified products would be available, before investing in this technology.

But businesses should be ready to make the move to the faster 802.11a and 802.11g technologies next year, Dulaney says. "When they mature in 2004, 802.11a wireless LANs will offer significant technological advantages over 802.11b networks," he says. Other than the bigger bandwidth, 802.11a has additional benefits for business, including a lack of interference from Bluetooth and consumer devices operating in the crowded 2.4-GHz band, and the availability of up to 13 channels in North America.

Vertical markets such as warehousing, manufacturing, health care, and education are the best bets for immediate deployment of wireless, Dulaney says. They will account for more than half of all wireless-equipped users, even through the end of 2004. "In warehouses and manufacturing, a wireless LAN decreases the number of inventory specialists required," he says, "making warehousing systems more efficient, less costly, and more accurate, with analysis of real-time inventory levels."