A neighborhood network feature found in various Amazon Echos (Alexa), Ring doorbells and cameras. Using Bluetooth Low Energy (BLE) for communications to nearby devices and LoRaWAN for longer distances, Amazon Sidewalk is designed to help people find lost pets and solve other neighborhood issues.
Sidewalk-capable devices are known as Sidewalk Bridges, and they use a small portion of the user's Internet bandwidth. The more Sidewalk Bridges activated in a neighborhood, the more useful the network becomes. See LoRaWAN