In their most basic form, Bluetooth® beacons broadcast packets of data, called advertisements, announcing their presence to nearby listeners like smart phones and Bluetooth gateways. Much more is possible though, as the advertisements can include location data, sensor information like environmental conditions – the temperature or humidity at the beacon’s location or other parameters, like the temperature of a person wearing a beacon. Advertisements can be transmitted continuously, or on an event basis, like advertising on motion, as determined by an accelerometer in the beacon. Beacons can also keep a log of the accelerometer and other sensor data, to be downloaded later when a receiving device is available, giving a history of the conditions that the beacon encountered.