Abstract: A system for warning of potential collisions among subjects includes devices configured to be transported by the subjects. At least one of the devices may have a device identifier and may include a transceiver configured to transmit radio frequency signals including the device identifier. At least one of the devices may include a processor operably connected to a transceiver configured to receive radio frequency signals. In at least one of the devices, the processor is configured to store another device's identifier in a storage medium, to determine a signal strength of a radio frequency signal received from the other device, and to issue a warning signal based at least in part on at least one of the signal strength and the other device's identifier. The warning signal is configured to warn a subject of a potential collision with another subject.

Abstract: A method for avoiding collisions may include receiving a signal from a device, where the signal includes an identifier of the device transmitting the signal. The method for avoiding collisions may further include determining strength of the signal. The method for avoiding collisions may further include reading from a database a threshold corresponding to an allowable distance to the device. The method for avoiding collisions may further include comparing the threshold to one of the determined strength of the signal and an approximate distance of the device calculated based on the determined strength of the signal. The method for avoiding collisions may further include issuing a collision warning if the one of the determined strength of the signal and the approximate distance of the device exceeds the threshold.