System and method for asset tracking and monitoring using antenna diversity
View Patent ↗A system and method for asset tracking and monitoring using antenna diversity. Antenna diversity ensures that the mobile terminal maintains good visibility of a satellite throughout the transport route. In one example, a first antenna is mounted on a first side of an asset transporter (e.g., flatbed trailer) and a second antenna is mounted on a second side of the asset transporter. A selector/combiner in the mobile terminal enables multiple antennas to be leveraged in the satellite communication process.
1. An asset tracking system for use on an asset transporter carrying an asset load, a form of said asset transporter precluding attachment of a device above said asset load, comprising:
a mobile terminal that is affixed to said asset transporter at a location on said asset transporter whose visibility to a satellite is reduced when a particular orientation of said asset transporter causes the asset load on said asset transporter to be between said mobile terminal and said satellite;
a first antenna coupled to said mobile terminal for receiving signals from said satellite, said first antenna being positioned on a first side of said asset transporter; and
a second antenna coupled to said mobile terminal for receiving signals from said satellite, said second antenna being positioned on a second side of said asset transporter different from said first side, said positioning of said first antenna on said first side of said asset transporter and said second antenna on said second side of said asset transporter causing at least one of said first and second antennas to have a relatively unobstructed view of said satellite for every orientation of said asset transporter relative to said satellite, said positioning of said first and second antennas on said asset transporter assuring that the asset tracking system receives satellite signals in said mobile terminal using at least one of said first and second antenna regardless of an orientation of said asset transporter relative to said satellite.
2. The system of claim 1 , wherein said first antenna is integrated with said mobile terminal.
3. The system of claim 2 , wherein said second antenna is coupled to said mobile terminal via a cable.
4. The system of claim 1 , wherein said mobile terminal includes a signal selector that selects a satellite signal from one of said first and said second antenna.
5. The system of claim 4 , wherein said selection is based on signal strength.
6. The system of claim 1 , wherein said mobile terminal includes a signal combiner that combines satellite signals received from said first and said second antenna.
7. The system of claim 1 , wherein said satellite signal is received from a communication satellite.
8. The system of claim 1 , wherein said satellite signal is received from a GPS satellite.
9. A mobile terminal for use with an asset tracking and monitoring system, said mobile terminal being affixed to a first side of an asset transporter at a position that has a reduced visibility to a satellite when a particular orientation of said asset transporter causes an asset load on said asset transporter to be between said mobile terminal and said satellite, comprising:
a first antenna for receiving satellite signals from said satellite;
an antenna port for connection to a second antenna for receiving signals from said satellite, said second antenna being positioned on a second side of said asset transporter different from said first side of said asset transporter on which said mobile terminal is mounted, said positioning of said first antenna on said first side of said asset transporter and said second antenna on said second side of said asset transporter causing at least one of said first and second antennas to have a relatively unobstructed view of said satellite for every orientation of said asset transporter relative to said satellite; and
a satellite receiver that is coupled to said first and said second antennas, said satellite receiver having an increased visibility to said satellite as compared to a visibility provided by said first antenna alone.
10. The mobile terminal of claim 9 , further comprising a signal selector that selects signals received by one of said first and said second antennas.
11. The mobile terminal of claim 9 , further comprising a signal combiner that selects signals received by one of said first and said second antennas.
12. The mobile terminal of claim 9 , wherein said asset transporter is a flatbed trailer.