A new patent application for "Wireless Audio Output Devices," was released this Thursday by the USPTO and US Patent and describes exactly how the new W1 chip that is included in the AirPods allows pairing settings. In Summary, the charging case that comes with AirPods functions as a physical synchronization interface.
In addition to a built-in battery, the case features its own microprocessor and communications stack, a motion detection cover to initiate the perfect synchronization process with an Apple device and a physical Bluetooth manual pairing button with non-hardware Apple , like Android phones.
During the synchronization process, each AirPod sends a shared signal for the charging case over a secure wireless link. This strengthens security and prevents malicious users from connecting wirelessly to AirPods to listen to phone calls and more.
The synchronization process requires the charging case because the AirPods themselves lack a pushbutton to start the synchronization. Once paired, AirPods are instantly available on every Apple device connected to iCloud with the same ID. With non-Apple hardware, standard Bluetooth pairing with a PIN code is required to connect the headset.
Each AirPod memory packet is housed in a module that stores the Bluetooth link information and unique headset MAC address. This allows the iOS battery widget to view the battery levels of the right and left AirPods, as well as the charging of the case.
Apple's invention also points to a primary AirPod that is paired and communicates with a secondary AirPod. In this way, a secondary handset then receives data and audio signals from the first handset. If a user takes an AirPod from their ear, a secondary AirPod then changes their way of working to receive data and audio signals from a host device.