Zwave is a communication protocol that uses RF (Radio Frequency) technology for home automation. Zwave operates at 908.42 MHz with a source-routed mesh networking topology and utilizes GFSK modulation technique. Z-Wave is designed to provide reliable, low-latency transmission of small data packets at data rates up to 100kbit/s with communication distance about 30 meters.
A Zwave network controller, is a central device to setup and manage the network while the other home devices are included before operation in the network. ZWave network is identified by a Network ID and each device is also identified by a Node ID.
The Network ID (4 bytes) is assigned to each device by the network controller when the device is added into the network, thus nodes with different Network ID’s cannot communicate with each other. The Node ID (1 byte) is the address of the device / node existing within network. Devices can communicate to one another by using intermediate nodes to route around.
Z-wave released later versions with added network discovery mechanisms so that ‘explorer frames’ with pruning algorithm could be used to heal broken routes caused by devices that have been moved or removed. A Z-Wave automation system can be remote controlled via the Internet, using a Z-Wave gateway or central control device which serves as both the Z-Wave hub controller and portal to the outside.