Smart watches and fitness bracelets with Bluetooth v5.1

Bluetooth v5.1

— the evolution of BLE with more reliable reconnection and economical background synchronization, plus potential support for "direction finding" (AoA/AoD) for precise device detection with the appropriate chipset and antennas. In everyday life, this results in fewer disconnections at home or in the gym, faster link recovery after leaving a room, and stable sensor telemetry transmission; compared to 5.0, the practical improvement is noticeable, and from 5.2–5.4, it is distinguished by additions like isochronous channels and refined broadcasting. Full backward compatibility: watches on 5.1 work with smartphones on 5.0/4.2, simply using the common set of features without losing basic functions of notifications, calls, and music control.