Transponder system for localization of an object

• US 6,236,836 B1
• Filed: 10/31/1994
• Issued: 05/22/2001
• Est. Priority Date: 05/11/1992
• Status: Expired due to Fees

• Current Assignee: Närhi, Anne, Tony Westman
• Original Assignee: Närhi, Anne, Tony Westman
• Inventors: Westman, Tony, Närhi, Anne
• Primary Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US08/325,448
• Time in Patent Office: 2,395 Days
• Field of Search: 379/56, 379/57, 379/58, 342/457, 340/988, 340/989, 340/991, 455/38.3, 455/343, 455/31.2, 455/31.3, 455/456-458, 455/419, 455/427, 455/11.1, 455/426, 455/574
• US Class Current: 340/7.1
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder

Abstract

A transponder system is provided which presents a light weight portable or mobile system for localization of movable objects, e.g., for surveillance of valuable transports and the like. The small unit constituting the transponder contains a receiver (1) of paging type, a decoder (2), a logic unit (3), a transmitter portion (10), a built-in antenna and power supply (11). The system is controllable by an existing tested radio system for paging. One advantage of utilizing an already existing paging system is that functionality is well tested and a general covering range is obtained. In addition, costs for building up and operation of a paging system are eliminated. Control information being sent to the transponder includes a number of symbols defining a certain basic function for the built-in marker transmitter (10) and symbols which constitute control code and control data for the specific function. Consequently at least the frequency, transmit power and transmitting sequences of the marker transmitter are controllable.

Claims

1. A transponder system (B) for localization of an object being provided with a transponder for this system comprising antenna device and a paging receiver (1) having an unique call, further comprising

a built-in marker transmitter (10) having a standby mode, and a working enabling mode during which said marker transmitter (10) is working on a fixed frequency different from the frequency of the paging receiver (1),

a unit (2) for decoding of an authorization code and a control information obtained via the paging receiver (1),

an electronic logic unit (3) for processing of control information obtained from the decoder (2),

a power supply (11) to permit the transponder system (B) and its marker transmitter (10) to operate during a certain minimum time period during the enabling mode, and

that operation of the marker transmitter (10) during the enabling mode is controlled by the logic unit (3) based on remotely transmitted control information obtained from the paging receiver (1) via the unit (2) for decoding.

2. The transponder system according to claim 1, characterized in that the logic unit (3) looks for the authorization code in the data information obtained by the decoder unit (2) which information is transferred by the use of calling telephone'"'"'s dialing buttons and received by the paging receiver (1) in question,

that when the logic unit (3) finds an authorization code being valid for the paging receiver (1) in question having the unique call it will further process data information sent over the telephone network and received by the paging receiver (1) over a radio paging network.

3. The transponder system according to claim 2, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained abut the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

4. The transponder system according to claim 2, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

5. The transponder system according to claim 2, characterized in that the additionally obtained data information constitutes control information for the marker transmitter (10), which information primarily via the electronic logic unit (3) enables or disables the marker transmitter (10).

6. The transponder system according to claim 5, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained abut the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

7. The transponder system according to claim 6, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

8. The transponder system according to claim 5, characterized in that said control information further is comprising for one part a number of symbols which is defining a certain basic function of said marker transmitter (10), while the remaining decoded symbols constitute additional control information for this specific function in form of control data, at least the frequency, transmit power and transmitting sequence of the enabled marker transmitter accordingly being controllable.

9. The transponder system according to claim 8, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained abut the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

10. The transponder system according to claim 8, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

11. The transponder system according to claim 8, characterized in that when said transponder (B) is receiving a call having a correct authorization code but no other data information said marker transmitter (10) always being enabled by said logic unit (3) through predetermined settings.

12. The transponder system according to claim 11, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained abut the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

13. The transponder system according to claim 12, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

14. The transponder system according to claim 11, characterized by further comprising an additional receiver (9) for the GPS system which receiver is being enabled parallelly to said marker transmitter (10),

in that received positioning information from said GPS receiver (9) is modulating said marker transmitter (10) for retransmission of the current position of said transponder (B).

15. The transponder system according to claim 14, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained abut the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

16. The transponder system according to claim 14, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

17. The transponder system according to claim 1, characterized in that said marker transmitter (10) is operating in the range preferably around 1000 MHz,

that said marker transmitter (10) additionally comprises a fixed frequency within the mobile radiotelephone band, said marker transmitter (10) when enabled in such a mode alternatingly transmitting a defined identification on the fixed frequency in the mobile radiotelephone band and alternatingly is transmitting on its ordinary defined different frequency for direction finding purposes, whereby a further rough information is obtained about the location where close positioning finding should take place due to the recognition of the network cell of the mobile radiotelephone system where said transponder (B) is localized.

18. The transponder system according to claim 17, characterized in that said transponder (B) identifies itself to the mobile radiotelephone system by utilizing its unique call, preferably in form of its phone number, whereby an enabled transponder (B) is simply identified by an existing mobile radiotelephone network.

19. The transponder system according to claim 17, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.

20. The transponder system according to claim 1, claims, characterized in that said marker transmitter (10) is additionally comprising a transmitting frequency preferably in the range 30-50 MHz and transmitted via its ordinary antenna or an extra connected antenna to further facilitate direction finding within areas having strong reflections in the UHF range where the ordinary marker frequency is transmitted.