System and method for real time asset location and tracking
A system for estimating the current position of an asset within a location that includes a transponder associated with the asset, a plurality of wireless interface devices provided within the location, and a central computer system in electronic communication with the wireless interface devices. The central computer system is adapted to: (i) identify a particular one or more of the wireless interface devices that have received a wireless signal from the transponder, and (ii) determine an estimate of the current position based on the identified particular one or more of the wireless interface devices.
1. A system for estimating a current position of an asset within a location, comprising:
a transponder associated with said asset;
a plurality of wireless interface devices provided within said location; and
a central computer system in electronic communication with said wireless interface devices, said central computer system being adapted to: (i) identify a particular one or more of said wireless interface devices that have at least received a wireless signal from said transponder, and (ii) determine an estimate of said current position based on the identified particular one or more of said wireless interface devices, wherein said location includes a plurality of sub-locations, wherein each of said sub locations includes a set of said wireless interface devices, wherein in each said sub-location a particular one of the set of said wireless interface devices included in the sub-location is structured to determine a sub-min-term for said transponder, the sub-min-term for each sub-location representing a plurality of Boolean variable values, each of said Boolean variable values being associated with a respective one of the wireless interface devices of the set of said wireless interface devices included in the sub-location and indicating whether the one of said wireless interface devices has at least received a wireless signal from said transponder, wherein said central computer system receives one or more of the sub-min-terms and determines said estimate of said current position based on said one or more of the sub-min-terms.
2. The system according to claim 1 , wherein said central computer system is further adapted to cause said wireless interface devices to generate a plurality of wireless interrogation signals, wherein said wireless signal from said transponder is generated in response to receipt of at least one of said wireless interrogation signals.
3. The system according to claim 1 , wherein said wireless signal from said transponder is generated continuously.
4. The system according to claim 1 , wherein said asset is either an animate object or an inanimate object.
5. The system according to claim 1 , wherein each of said Boolean variable values is a 1 if the one of said wireless interface devices associated with the Boolean variable values has received the wireless signal from said transponder and otherwise is a 0.
6. The system according to claim 1 , wherein each of said Boolean variable values is a 1 if the one of said wireless interface devices associated with the Boolean variable values has received and recognized as valid the wireless signal from said transponder and otherwise is a 0.
7. The system according to claim 1 , further comprising a plurality of wireless access points provided within said location, each of said wireless interface devices being in electronic communication with said central computer system through at least one of said wireless access points.
8. The system according to claim 7 , wherein the wireless access points at least in part implement a wireless network according to the IEEE 802.11 set of standards.
9. The system according to claim 8 , wherein said wireless interface devices are adapted to wirelessly communicate with said transponder at a first frequency and with at least one of said wireless access points at a second frequency that is different than said first frequency.
10. The system according to claim 1 , wherein each of said wireless interface devices is in electronic communication with said central computer system through a wired connection.
11. The system according to claim 1 , wherein each of said wireless interface devices is in electronic communication with said central computer system over existing power lines.
12. The system according to claim 1 , wherein said location is one or more buildings.
13. The system according to claim 1 , wherein said transponder includes an electronic device having an inactive, sleep state and an active state, wherein said electronic device consumes power from a power source of said transponder in said active state, and wherein in response to receiving the at least one of said wireless interrogation signals, the transponder is structured to convert said the at least one of said wireless interrogation signals into at least one DC signal without consuming power from said power source or another power source within or connected to said transponder, and provide a wake-up signal to said electronic device, said wake-up signal causing said electronic device to move from said inactive, steep state to said active state, wherein thereafter said wireless signal is generated by said transponder.
14. The system according to claim 1 , wherein said central computer system receives all of the sub-min-terms and determines said estimate of said current position based on all of the sub-min-terms.
15. The system according to claim 1 , wherein said central computer system receives less than all of the sub-min-terms and determines said estimate of said current position based on less than all of the sub-min-terms.