The document discusses home automation and security systems. It describes a 4-level node system to control different automation aspects through sensors, controllers and actuators. Level 0 nodes are sensors that connect to Level 1 interface nodes. Level 1 nodes control Level 0 nodes and provide a user interface. A base station connects Level 1 nodes to a central server. Level 2 nodes control audio/video and connect directly to the server. Level 3 nodes may provide video streaming. The system uses various wired and wireless technologies to connect nodes and devices.