Ideally, dual-band Wi-Fi adapters let you run 802.11a and 802.11b wireless networks side by side according to your need and budget. The 54Mbps 802.11a is up to five times faster than 802.11b-and about five times as expensive. Unfortunately, the two technologies' data transmissions don't mix. But new transceivers from Intel and others for about $650 run 802.11a and 802.11b networks side by side. Also, $125 to $160 dual-band PC cards from firms like D-Link let mobile users tap networks wherever they go. "A is for halls, b is for walls," says mobile analyst Ken Dulaney, referring to 802.11a, which works well in open spaces, vs. 802.11b, which is better at penetrating walls. 802.11b is fine for sending documents in an office, but 802.11a lets you browse the Web and download files in commercial hotspots.
Dulaney says dual adapters are here to stay, but networking protocols are not set in stone. Europe is demanding changes to 802.11a, that could affect existing hardware. Then 802.11g rivaling 802.11a's speeds could challenge the status quo. Experts recommend waiting until year-end 2003 for large-scale Wi-Fi deployments.
San Francisco-based Erik P. Nelson is a frequent contributor to Entrepreneur.