Many of my projects deal with real time tracking and instrumentation. Tracking containers is a natural outgrowth. There are many challenges. Very low power embedded technology is necessary as containers aren't tethered to power. Network connectivity (satellite or terrestrial) to report location derived from GPS. Cryptographic protection to ensure the efforts aren't subverted. Interoperability of the RF linked management systems across trucks, trains, aircraft, ships and ports.
I have another project related to the nuclear waste train. It has similar requirements for instrumentation and tracking. That is going to be a longer execution time frame because of the requirement to run 100,000 miles around the test loop at Pueblo, CO.