Buzz over ZigBee

The Buzz Over ZigBee

Focusing on the short range may be bad for business--unless you're talking about remote control technology. The latest short-range wireless option is known as ZigBee, an open standard created by a nonprofit consortium of companies called the ZigBee Alliance.

ZigBee chips require very little power, which means they can be operated for long periods using only a battery. However, because they send and receive data at a low rate, these chips are not right for pushing large amounts of data; rather, the technology is designed to help create wireless sensor networks for close-range remote monitoring, home control, and building automation network applications. While many applications are consumer oriented, some business security uses are foreseen.

RAE Systems, a Sunnyvale, California-based manufacturer of chemical and radiation sensors, has recently rolled out RAEWatch, a wireless sensor bundle that can be used in applications such as monitoring public venues or securing cargo containers.

Bob Durstenfeld, director of corporate marketing for the firm, explains how a shipping container equipped with ZigBee sensors could be monitored: "You'd have a transponder on the dock, on the truck carrying the container to the dock, and on the ship. You'd uplink it and keep track in real time of your containers." The container could thus be tracked from ship to dock to truck to its destination.

Durstenfeld compares the workings of a ZigBee radio network to the Internet, where packets move nonlinearly from server to server until they reach their destination. "The beauty of ZigBee is that it forms an ad hoc network," he says. "It lets you have a cloud of sensors that can talk from sensor to sensor and act as their own repeaters. You can monitor multiple points from one central point or one edge point of the cloud of sensors." Unlike a hub-and-spokes configuration, where if one radio drops, the signal is lost, "ZigBee lets you talk from the closest radio," he says.

Regardé is a new business that plans to sell products with ZigBee technology. Cofounder Jared Richard Brandt says the company is running a beta test with hundreds of homeowners who have installed in their homes some ZigBee-enabled sensors that can detect door openings, smoke, and carbon dioxide, and other sensors that control low-power electric devices such as lights.

The sensors communicate via the ZigBee protocol to a small Linux-based device with a built-in e-mail server that is connected to a homeowner's computer. So, for example, a parent can be notified at work via e-mail when a child has returned from school. Next generation devices will tie into traditional alarm-monitoring services, Brandt says.

One homebuilder, eager to protect homes under construction and high-value tools left on building sites, is working with Regardé to use Zigbee to monitor entry and exit to the work sites using motion detectors activated after working hours. These sensors would transmit data back to a base station that would be housed in one of the model homes, where a broadband connection would allow a project manager to monitor any movement on the site after the construction site was closed for the night. An alert could also be sent to an alarm-monitoring company.

Brandt points out that the transmissions are encrypted; he notes, however, that some security issues are inevitable, because ZigBee devices need to be visible to function. As for security, Chris Lopez, an analyst with market research company ABI Research who forecast high-growth for the ZigBee market, says the specifications have been closely watched to ensure that the technology is secure from attack. But like the Bluetooth protocol before it, problems with ZigBee are not likely to come to light before products are rolled out and security researchers start poking holes in it.