Wi-Fi Looks to Simplify Network Switching

LAS VEGAS -- The Wi-Fi Alliance aims to make sure dual-band wireless LAN clients can efficiently find and hop onto the fastest network available even if it was made by a different vendor.

The consortium of vendors of IEEE 802.11 wireless LANs will begin as soon as November 29 certifying products that include support for both the IEEE 802.11b standard, which delivers 11 megabits per second maximum bandwidth on the 2.4-GHz radio spectrum, and IEEE 802.11a, which offers as much as 54 mbps on the 5-GHz range.

Although there already are products on the market that are built to support each standard as written by the Institute of Electrical and Electronics Engineers (or IEEE), Wi-Fi will test to make sure products from different vendors work together smoothly, said Sarosh Vesuna, a member of the group's board, in a briefing Monday here at the Comdex trade show.

Handling Handoffs

Wi-Fi also has set down rules for how clients and wireless access points should handle a handoff, which should take place when a user with a dual-band wireless LAN client moves from the range of an 802.11b network into the area covered by an 802.11a network, or vice versa.

For example, the group is working on ways to avoid a client system jumping back and forth between the two types of networks when the user moves in and out of range of a faster network. Once it has a satisfactory connection to one network, the client would stick to that system. These types of issues, in addition to establishing interoperability among actual products, are beyond the scope of the IEEE, which writes standards but gives vendors some discretion as to how they implement them, Vesuna said.

Although a test bed is in place and products can begin to undergo testing starting November 29, dual-band products probably won't go on sale with Wi-Fi certification until mid-December, he added.

Products built to the IEEE 802.11g standard, a nearly complete specification that would deliver 54 mbps bandwidth on the 2.4-GHz spectrum, probably won't be certified as interoperable by Wi-Fi until the fourth quarter of 2003, said Wi-Fi spokesperson Brian Grimm. When they are certified, Wi-Fi won't call them 802.11g products, he added. It plans to call them 54 mbps 802.11b, because focus groups of potential customers have shown users are confused by the alphabet soup of wireless LAN standards, Grimm said.