Mobile communication devices, like smartphones, cooperatively interact with one another and with a communication provider, like a cellular telephone provider, to manage power usage by the mobile devices, where the communication capabilities of the devices are still retained. For example, for two mobile devices, the first device may be placed into a reduced-power mode, while the second device remains in a non-reduced-power mode. The second device at least partially assumes the communication capability of the first device so that the communication capability of the first device is retained.