In the smart home, the term gateway stands for the smart home control center: All smart home sensors (e.g. window sensor, Smart home devices (e.g., water sensors) send their data to the gateway via the Zigbee wireless protocol. The gateway processes the received data and triggers an action if necessary. A concrete example: If the window sensor reports that a window has been opened, the gateway triggers the action "Turn down the heating" and sends this command to the radiator thermostat. The gateway also feeds the received information into the Wi-Fi network so that the smart home owner can access it via an app on their smartphone. The flow of information also works the other way around: The smart home owner can use their smartphone to issue commands that the smart home components should execute, e.g., "Turn off the lights in the living room." Here, too, the command is first sent to the gateway, which then forwards it to the affected components.
Some gateways are connected to a Cloud connected, such as the Smart Home Hub of the essentials brand. Others offer local control of the Smart Home devices, where the Smart Home data is not forwarded to the cloud, such as the USB gateway from ConBee. For the smart home to function without the cloud, a dedicated server is required as a storage center for the smart home data.
