Method for tracking containers using a low-rate wireless personal area network system

摘要

A method for tracking a plurality of containers each joined to an electronic tracking device having routing capabilities and a WPAN-enabled radio receiver/transmitter configured to attempt to connect to a pre-configured WPAN upon being activated comprises activating the radio receiver/transmitter of each tracking device joined to a container being loaded onto a cargo vessel; receiving an indication from each tracking device that fails to connect to the WPAN; intermittently performing a network scan to locate each WPAN-connected tracking device; intermittently configuring the WPAN to include each WPAN-connected tracking device in a hybrid tree-mesh network topology; intermittently configuring routing information stored on each WPAN-connected tracking device to maintain mutual communication with each WPAN-connected tracking device and enable mutual communication between each WPAN-connected tracking device; receiving transport-related data from each WPAN-connected tracking device; transmitting the transport-related data to a control station through a LAN on the vessel; broadcasting a request to be routed between the WPAN-connected tracking devices in a depth-first traversal of the network topology that directs each WPAN-connected tracking device to enter a low-power mode when the depth-first traversal backtracks from the tracking device; and receiving an acknowledgment of the request communicated from each WPAN-connected tracking device when the tracking device enters the low-power mode.