Apple looking to extend battery life by tinkering with ways to power-off Bluetooth
Apple notes that even though some Bluetooth enabled products have timing circuits that turn off the device after a certain amount of time of not being in use, that too also uses the battery even when it is not being used. Apple's idea would allow the user to turn off one Bluetooth device and have the rest follow in-line. Besides turning off power, the linked Bluetooth enabled products could also change the settings of the device it is linked to, like an Apple iPhone.
An Apple iPhone could be preset to automatically turn off all Bluetooth connected devices, or allow minimal Bluetooth activity, when the headphones are turned off. This would allow users to change levels of their Bluetooth communications to "Sniff, Hold or Park" modes. In the "Sniff" mode, a device "sniffs" around for a Bluetooth signal using a reduced amount of power. "Hold" means that a device is connected to Bluetooth but is not being used while "Park" means that the device is connected and is active. Not only can this save battery life on an Bluetooth connected device, but also on the Apple iPhone as well. In the patent application, Apple says that an iPhone could switch to a battery saving mode until a call is received.
Bluetooth 4.0 comes with the new Apple iPhone 4S, set for release on Friday. This version of Bluetooth offers three modes, "Classic Bluetooth," "Bluetooth High Speed" and "Bluetooth Low Energy". The latter offers connectivity up to 160 feet for applications that require low-power, a longer range than the competing RFID has.
source: FreePatentsOnline via AppleInsider