One of the biggest challenges within the currently marketed track and trace systems is the difficulty of communicating when the container does not have a field-of-view of the sky or strong connectivity to ground-based networks such as cellular or trunked radio, including containers stacked for ocean transport.
A specific leading product that claims to give real-time tracking, admitted that it cannot track a shipment on the ocean real-time when there is no cellular or Wi-Fi signal, so the customer only receives its location data once its container reaches its destination Port, if it ever does.
The cost for repositioning containers within the US is approximately $500 Million per year, per ocean carrier. The average turn-time (round trip) per container globally is 4 round turns per year. With accurate tracking of empties, the ocean carriers can each gain up to 2 additional turns per container per year, but easily 1 additional turn per year. That is a huge cost reduction!