Key fobs, also known as remote keys or remote transmitters, have become a common piece of equipment in today's vehicle, being ubiquitous in every market segment. Once limited to remote locking and unlocking operations, today's key fobs can be used to control many comfort and security features beyond locking and unlocking, such as alarm system operation, vehicle locate, approach lighting, memory seat recall, and remote starting systems. Key fobs are designed to be easy to use as well as easy to carry and transport in personal containers, such as purses, pockets, wallets, and the like.
Accordingly, as with other personal effects, key fobs and other portable remote devices can be lost or misplaced or can be otherwise difficult to find. Even with careful tracking of a remote device, children and pets, among other factors, can make location difficult. Moreover, multiple remote devices are often distributed with each vehicle. In the event that more than one remote device becomes lost or misplaced, finding them again can require additional effort.
System designs and strategies are presented for the use of a bidirectional communication system as a mechanism to request a misplaced or lost key fob to annunciate its presence through one or more mechanisms. Furthermore, strategies are discussed to enhance the coverage area in which the misplaced key fob will respond when an annunciation request is initiated.