Abstract: A uniform protocol can facilitate secure, authenticated communication between a controller device and an accessory device that is controlled by the controller. An accessory and a controller can establish a pairing, the existence of which can be verified at a later time and used to create a secure communication session. The accessory can provide an accessory definition record that defines the accessory as a collection of services, each service having one or more characteristics. Within a secure communication session, the controller can interrogate the characteristics to determine accessory state and/or modify the characteristics to instruct the accessory to change its state.

Abstract: A uniform protocol can facilitate secure, authenticated communication between a controller device and an accessory device that is controlled by the controller. An accessory and a controller can establish a pairing, the existence of which can be verified at a later time and used to create a secure communication session. The accessory can provide an accessory definition record that defines the accessory as a collection of services, each service having one or more characteristics. Within a secure communication session, the controller can interrogate the characteristics to determine accessory state and/or modify the characteristics to instruct the accessory to change its state.

Abstract: A portable electronic device that can receive power from an internal power source (such as a battery) and/or a second portable electronic device is described. In order to coordinate the power availability in these portable electronic devices, a power-management mechanism in the portable electronic device (which may be implemented in hardware and/or software) may determine a power state of an internal power source in the second portable electronic device, and may accordingly adjust a power consumption by circuits in the portable electronic device and/or the power received from the second portable electronic device. In this way, the power-management mechanism may approximately synchronize the power consumption in the portable electronic devices and/or the power states of the internal power sources in the portable electronic devices. This approximate synchronization may facilitate concurrent operation of the portable electronic devices.

Abstract: A portable electronic device that can receive power from an internal power source (such as a battery) and/or a second portable electronic device is described. In order to coordinate the power availability in these portable electronic devices, a power-management mechanism in the portable electronic device (which may be implemented in hardware and/or software) may determine a power state of an internal power source in the second portable electronic device, and may accordingly adjust a power consumption by circuits in the portable electronic device and/or the power received from the second portable electronic device. In this way, the power-management mechanism may approximately synchronize the power consumption in the portable electronic devices and/or the power states of the internal power sources in the portable electronic devices. This approximate synchronization may facilitate concurrent operation of the portable electronic devices.