Abstract: Communications devices such as cellular telephones share resources, for example to conserve battery capacity or to enable a device to perform a function not available to another one of the devices. Such devices may find particular utility in a mobile personal emergency response (MPERS) environment, and may enable clients of an MPERS service to take better advantage of the service. The devices communicate over a local wireless communications system to determine which device may perform a particular function. Other resources that may be shared include cellular connectivity and global positioning capability.

Abstract: Communications devices such as cellular telephones share resources, for example to conserve battery capacity or to enable a device to perform a function not available to another one of the devices. Such devices may find particular utility in a mobile personal emergency response (MPERS) environment, and may enable clients of an MPERS service to take better advantage of the service. The devices communicate over a local wireless communications system to determine which device may perform a particular function. Other resources that may be shared include cellular connectivity and global positioning capability.

Abstract: A method of operating a communications device to maintain a position fix of the communications device includes obtaining a position fix using a position determination capability of the device, such as a global positioning system capability. The method further includes emitting a first acoustic signal, and recording a baseline acoustic signature in response to the emission of the first acoustic signal. The method further includes emitting an additional acoustic signal and recording an additional acoustic signature resulting from the emission of the additional acoustic signal, comparing the baseline acoustic signature with the additional acoustic signature, and estimating, based at least in part on the comparison of the baseline and additional acoustic signatures, whether the communications device has moved between the recordings of the baseline and additional acoustic signatures.

Abstract: A method of operating a communications device to maintain a position fix of the communications device includes obtaining a position fix using a position determination capability of the device, such as a global positioning system capability. The method further includes emitting a first acoustic signal, and recording a baseline acoustic signature in response to the emission of the first acoustic signal. The method further includes emitting an additional acoustic signal and recording an additional acoustic signature resulting from the emission of the additional acoustic signal, comparing the baseline acoustic signature with the additional acoustic signature, and estimating, based at least in part on the comparison of the baseline and additional acoustic signatures, whether the communications device has moved between the recordings of the baseline and additional acoustic signatures.