Selective reporting of events in asset tracking system

1. A method comprising:

entering an event masking parameter into a server computer;

generating an event masking rule based at least in part on the entered event masking parameter;

downloading the event masking rule from the server computer to an asset tracking unit;

detecting an event, said detecting occurring at the asset tracking unit; and

determining at the asset tracking unit, based at least in part on the downloaded event masking rule, whether to report the detected event;

wherein the detected event is at least one of: coupling to a truck tractor of a truck trailer to which the asset tracking unit is attached; and de-coupling from a truck tractor of a truck trailer to which the asset tracking unit is attached.

2. The method of claim 1 , wherein the downloading occurs at a time when the asset tracking unit is attached to a transportation vehicle.

3. The method of claim 2 , wherein the transportation vehicle is a truck trailer.

4. The method of claim 2 , wherein the transportation vehicle is a cargo container.

5. The method of claim 1 , wherein the event masking rule provides that the detected event is not to be reported during certain hours of a day.

6. The method of claim 1 , wherein the event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is not within a certain geographical area.

7. The method of claim 1 , wherein the event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is within a certain geographical area.

8. A method comprising:

providing an asset tracking unit that is attached to a transportation vehicle;

detecting an event that is related to the transportation vehicle, said detecting occurring at the asset tracking unit; and

determining, based at least in part on an event masking rule, whether to report the detected event;

wherein the detected event is at least one of: coupling of the transportation vehicle to a truck tractor; and de-coupling of the transportation vehicle from a truck tractor.

9. The method of claim 8 , wherein the event masking rule provides that the detected event is not to be reported during certain hours of a day.

10. The method of claim 8 , wherein the event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is not within a certain geographical area.

11. The method of claim 8 , wherein the event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is within a certain geographical area.

12. The method of claim 8 , wherein the determining step is performed at the asset tracking unit.

13. The method of claim 8 , wherein the determining step is performed at a central station.

14. The method of claim 8 , wherein the transportation vehicle is a truck trailer.

15. The method of claim 8 , wherein the transportation vehicle is a cargo container.

16. A method comprising:

providing an asset tracking unit that is attached to a truck trailer;

detecting an event in which the truck trailer is coupled to a truck tractor; and

reporting that the truck trailer has been coupled to the truck tractor only if the asset tracking unit detects that the truck trailer is moved by at least a predetermined distance after the asset tracking unit detects that the truck trailer has been coupled to the truck.

17. A method comprising:

providing an asset tracking unit that is attached to a transportation vehicle;

detecting an event in which a door of the transportation vehicle is opened or closed; and

refraining from reporting the event unless the event occurred within less than a predetermined period of time after at least one prior event in which the door was opened or closed.

18. An asset tracking system comprising:

a server computer;

a plurality of asset tracking units, each attached to a respective transportation vehicle; and

a central station;

the server computer programmed to:

receive inputs from at least one user to enter at least one event masking parameter;

generate at least one event masking rule based at least in part on the entered at least one event masking parameter; and

download the at least one event masking rule to at least one of the asset tracking units; and

the at least one of the asset tracking units programmed to:

receive and store a downloaded event masking rule;

detect an event; and

determine, based at least in part on the downloaded at least one event masking rule, whether to report the detected event to the central station;

wherein the detected event is at least one of: coupling one of the transportation vehicles to a truck tractor; and de-coupling one of the transportation vehicles from a truck tractor.

19. The asset tracking system of claim 18 , wherein each of the asset tracking units includes a GPS (Global Positioning System) receiver.

20. The asset tracking system of claim 18 , wherein the downloaded event masking rule provides that the detected event is not to be reported during certain hours of a day.

21. The asset tracking system of claim 18 , wherein the downloaded event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is not within a certain geographical area.

22. The asset tracking system of claim 18 , wherein the downloaded event masking rule provides that the detected event is not to be reported at times when the asset tracking unit is within a certain geographical area.

23. The asset tracking system of claim 18 , wherein the central station includes the server computer.

24. The asset tracking system of claim 18 , wherein at least some of the transportation vehicles are truck trailers.

25. The asset tracking system of claim 18 , wherein at least some of the transportation vehicles are cargo containers.