1. Avalanche beacons are worn by backcountry skiers and help rescuers locate buried victims after an avalanche. The beacons constantly transmit radio signals to be detected. 2. When searching for victims, rescuers switch their beacons to detection mode. The direction of strongest signal is followed to help pinpoint locations. 3. Over time, avalanche beacons haven't significantly changed in design or functionality, relying on radio transmission between search and rescue modes. However, new technologies like satellite communication could enhance their effectiveness.