Illustration: Dan Page

Wi-Fi is one of the great success stories of the past decade, and the industry that's grown up around it hasn't been standing still. In the past few years, amendments to the IEEE 802.11 family of standards have improved security and greatly increased the speed with which data can be moved around. Soon Wi-Fi access points will be able to cluster together in what are called mesh networks, making large wireless networks cheaper to operate by allowing a cluster of access points to exchange traffic and share a single high-speed connection to the Internet. Last March, an IEEE task group approved the new mesh capability, known formally as 802.11s.

Meshing is already used in some wireless applications—for example, in the sensor networks used to monitor manufacturing processes and in heating, ventilation, and air-conditioning systems. In 2003, the IEEE approved a standard for those networks, 802.15.4, popularly known as ZigBee. Unlike the new Wi-Fi standard, ZigBee was designed to support relatively low-power, low-data-rate networks.

There is also a need for high-speed mesh networks, and indeed several Wi-Fi and other wireless equipment makers already offer access points that use proprietary mesh-networking techniques. They include Motorola Inc., of Schaumburg, Ill.; Nortel Networks Corp., in Brampton, Ont., Canada; and Tropos Networks Inc., of Sunnyvale, Calif. Last year, Tropos's mesh equipment gave critically needed Internet access to residents and emergency workers in New Orleans and other U.S. cities in the Gulf region immediately after Hurricane Katrina. The city government of Las Vegas uses a mesh network to support many municipal activities; its network's technology is based on military research commercialized by Mesh Network Inc., which is now part of Motorola [see "Viva Mesh Vegas," IEEE Spectrum, January 2005]. And Nortel recently built a network in Taipei with almost 10 000 nodes.

In addition to these companies, at least 12 others contributed to the effort to draft the new standard, including such industry powerhouses as Cisco and Intel. Once their products conform to 802.11s, mesh networks can be built up using equipment from any of them, lowering costs and improving reliability.