Zwave and Zigbee are two standards for wireless networking of sensors and controls. Both implement meshes of nodes and can recover from failed or missing nodes. Both are designed for extremely low-power operation, targeting applications where battery-powered sensors must be in service for months or years at a time.
Zigbee is an open standard. Of the two, it is more complex, and perhaps more complete. Extremely large networks (65K nodes) can be created and managed. Zigbee seems to be targeted at industrial sensor applications – temperature and humidity in a factory, for example. There is an assumption that the user of the technology is fairly sophisticated.
ZWave is a proprietary standard targeted at the home user. It supports networks of at most 200 nodes. Initial devices currently implement controls (switches and remotes) and lighting controls. Some thermostats have been produced with ZWave capability. Network setup has been simplified for the home user. The USB ZWave “dongle” shown below has one large “pairing” button that sets up a connection between the dongle and a slave device. The dongle is then plugged into a host computer running home automation software.
Some sensors exist for ZWave networks. Most are motion detectors and door sensors for home security applications. One interesting sensor from Homeseer implements motion, temperature and light-level sensors in a single battery-powered unit. This relatively new device seems to be popular with enthusiasts for custom applications.