| 摘要 |
A non-transitory computer readable medium containing computer program instructions for monitoring whether persons in a group are each away from an associated vehicle. In one embodiment, the computer system receives an association between each of multiple persons in the group with one of multiple vehicles and automatically receives digital information, derived from measured rf signal strength, indicating whether any one of multiple persons in the group has moved from a first relatively close position with respect to an associated vehicle and farther away from the associated vehicle than the first position. A notification is sent from the computer system to at least one device associated with a person in the group based on received information that a first of said multiple persons is farther away from the associated vehicle than the first relatively close position is from the associated vehicle. |
