Patent ID: 9020526
Filing Date: 2015-04-28
Classification: G01S

Abstract:
1. A method for operating a set of tracking devices comprising: detecting location information via a selected one of the tracking devices; automatically sending a broadcast message including a unique identifier for the selected tracking device and the detected location information from the selected tracking device to one or more other tracking devices; automatically receiving broadcast messages from other tracking devices including unique identifiers and detected location information for the other tracking devices; the broadcast messages being sent and received between tracking devices over a first type of wireless communication channel; at least one of the tracking devices also sending and receiving messages over a second type of communication channel to a nearby user device, the user device including a general purpose computer with a user interface, the user interface to permit an operator of user device to operate the general purpose computer to send a query message to the selected one of the tracking devices to locate any tracking device of interest that is within range of another tracking device to receive the broadcast messages therefrom, even with the tracking device of interest not being directly connected to the user device and/or out of range of the first wireless communication channel; such that no single general purpose computing device serves as a central point for collecting and distributing location information among tracking devices, the user devices, and/or other general purpose computing devices; rebroadcasting received broadcast messages, wherein the broadcast messages further include a sequence number and wherein the broadcast messages include a hop count field and wherein the method additionally comprises: incrementing the hop count field each time a message is rebroadcast; and dropping messages having a hop count that exceeds a certain amount.