As an example, he cited the city traffic department's network of cameras to monitor traffic flow around the city. The mesh network could be used to bring images from the cameras back to the traffic management center. It could also help municipal work crews, equipped with mesh-enabled laptops out in the field, to download instructions and schematics from city databases.

Before long, interest began to spread to other city departments. For emergency services, for instance, Cheetah recently staged a demonstration of how responders could use the network to communicate during an emergency that included videoconferencing in the field. Cervantes has lent the fire department some mesh cards so it can start testing the pilot network.

The mesh network also offers an opportunity for Las Vegas to solve its interoperability problem. What visitors think of as a single glitzy metropolis is actually a patchwork of municipalities and areas that fall under the control of the surrounding county. Even the Las Vegas Strip, the city's signature avenue of outlandish hotels and casinos, is nearly all part of an unincorporated township called Paradise.

As a result, when major problems arise, it's difficult to coordinate the different agencies involved, such as the fire and police departments. "We've got four or five different cities, and it seems that each city has a different communications system," says Cervantes. "The mesh network could be a way to bridge that interoperability gap" if each city joined the mesh network.

Cervantes and Cheetah worked out a deal to start building a proof-of-concept network last summer. The Las Vegas traffic department agreed to provide most of the manpower and the lampposts needed to deploy the network hardware and pay Cheetah $25 000 to defray its costs. Cheetah provided all the equipment but retains ownership of it, pending the city's decision on installing a full-scale network.

Cheetah refuses to disclose the per-unit cost of the equipment but said the Las Vegas pilot network cost about $175 000—or roughly $80 000 per 2.6 km2. Of that, $30 000 pays for things like the servers Cheetah uses to manage the network and the cost of connecting it to the Internet, but the bulk, $50 000, is the cost of the mesh hardware itself.

Cheetah's hardware comes from Maitland, Fla.-based MeshNetworks Inc. [see "10 Tech Companies for the Next 10 Years," IEEE Spectrum, November 2003]. As this article went to press, communications technology giant Motorola Inc. announced it had signed an agreement to acquire MeshNetworks, with the stated intention of introducing mesh technology across all of Motorola's business units, from home entertainment to cellphones. While Motorola has its own sales force, licensed resellers such as Cheetah have been grandfathered into the agreement, says Rick Rotondo, MeshNetwork's vice president of marketing. He expects that many of MeshNetwork's current resellers will be used on a contract basis by Motorola to deploy and operate future mesh systems, because of their experience and wealth of regional contacts.

Cheetah also sells two other types of mesh networks based on hardware from Tropos Networks Inc., in Sunnyvale, Calif., and BelAir Networks Inc, in Kanata, Ont., Canada. The Tropos and BelAir mesh systems are built on top of the IEEE 802.11 Wi-Fi protocol, while MeshNetworks uses a proprietary technology originally developed for military applications.

Compared with the Wi-Fi-based mesh systems, the military-derived technology offers improved resistance to radio interference, better security, built-in geolocation, and the ability to offer different levels of service to different types of users. It also allows users to move about seamlessly within the entire coverage area, instead of having to re-establish a connection as they move from one Wi-Fi hotspot to another.

Within the Las Vegas MeshNetworks system, the average transmission speed ranges from 500 kilobits per second to 1.5 Mb/s, with bursts of up to 6 Mb/s possible. The backbone of the network is made up of 33 or so shoe-box-size gray boxes attached to traffic-light poles high above the streets, known as wireless routers [see photo, "Betting on the House"]. During the pilot deployment, city workers with a bucket truck managed in one 8-hour shift to put up 18 routers, says Cheetah's Gonzalez. Routers are simply bolted to lampposts and plugged into the photocell power adapter that sits atop most streetlights. The routers are then automatically assimilated into the mesh network. The most time-consuming element of installing or removing one is the time required to put traffic cones around the work area.