Z-Wave addressing

Z-Wave has a fairly simple addressing mechanism compared to Bluetooth and Zigbee protocols. The addressing scheme is kept simple because all attempts are made to minimize traffic and conserve power. There are two fundamental addressing identifiers that need definition before proceeding:

• Home ID: This is a 32-bit unique identifier that is preprogrammed in controller devices to assist with identifying Z-Wave networks from each other. During network start, all Z-Wave slaves have a home ID of zero and the controller will systematically populate the slave nodes with the correct home ID.
• Node ID: This is an 8-bit value that is assigned to each slave by the controller and provides addressing of slaves in the Z-Wave network. 

The transport layer provides several frame types to assist with retransmission, acknowledgment, power control, and authentication. The four types of network frames include:

• Singlecast frame: This is a packet sent to a single Z-Wave node. This type of packet must be followed by an acknowledgment. If the ACK doesn't occur, a retransmission sequence transpires.
• ACK frame: This is the acknowledgment response to a singlecast frame.
• Multicast frame: This message is transmitted to more than one node (up to 232). No acknowledgment is used for this type of message. 
• Broadcast frame: Similar to a multicast message, this frame is transmitted to all nodes in the network. Again, no ACK is used.

For a new Z-Wave device to be used on the mesh, it must undergo a pairing and adding process. The process is usually started by a mechanical or user instantiated keypress on the device. As mentioned, the pairing process involves the primary controller assigning a home ID to the new node. At this point, the node is said to be included.