Dual RF/IR communication device and method of use thereof

• US 6,574,482 B1
• Filed: 11/05/1999
• Issued: 06/03/2003
• Est. Priority Date: 11/03/1999
• Status: Expired due to Term

• Current Assignee: Centrak Incorporated (Halma PLC)
• Original Assignee: Elpas Electro-Optic Systems Limited
• Inventors: Radomsky, Israel, Abrams, Israel, Bruslavsky, Yossef
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Tran, Congvan
• Application Number:
  US09/434,716
• Time in Patent Office: 1,306 Days
• Field of Search: 455/150.1, 455/151.1, 455/151.2, 455/151.4, 455/903, 455/550, 455/456, 340/573.4, 340/572.1, 340/825.36, 340/825.39, 340/825.71, 340/825.72, 340/825.49, 379/56.1, 379/56.2, 379/56.3, 359/109, 359/155, 359/152
• US Class Current: 455/517
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/1127 using markers
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: G08B 21/0222 Message structure or message content, e.g. message protocol
• CPC Class Codes: G08B 21/0227 System arrangements with a plurality of child units
• CPC Class Codes: G08B 21/023 Power management, e.g. system sleep and wake up provisions
• CPC Class Codes: G08B 21/0247 System arrangements wherein the alarm criteria uses signal strength
• CPC Class Codes: G08B 21/0286 Tampering or removal detection of the child unit from child or article
• CPC Class Codes: G08B 3/1083 Pager locating systems
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information

Abstract

A communication device including an RF transmitter mounted in conjunction with an IR transmitter allowing data to be transmitted by RF as well as by IR. Such a device may be a portable badge worn by moving personnel to transmit IR and RF signals to one of a plurality of second devices each being a fixed reader having an IR and RF receiver, and typically being mounted in a respective enclosed space, such as a room. In use, IR transmissions from the portable device are detected by the IR receiver of the reader in the same room and thus provide an immediate identification of the room (or enclosed space) wherein the portable device is located. On the other hand, if the IR transmitter in the portable device is concealed or for any other reason is not within line-of-sight of the reader in its immediate proximity, then the RF signal transmitted by the RF transmitter in the portable device is detected by the RF receiver in the reader, thereby allowing tracking of the portable device in either eventuality.

Claims

1. A portable device including an RF transmitter mounted in conjunction with an IR transmitter for transmitting data by RF as well as by IR, and further including

an IR receiver for receiving an IR acknowledge signal, allowing a reader to establish location of the portable device as an enclosed zone in which an IR data signal transmitted by the portable device is received by the reader and allowing the reader to establish location of the portable device based on a measured signal strength of a received RF signal if no IR data signal is received within a predetermined time;

said RF transmitter being adapted to transmit only if the IR receiver does not receive the IR acknowledge signal within said predetermined time following transmission of the IR data signal by the IR transmitter.

2. The device according to claim 1, wherein:

the IR transmitter is adapted to transmit bursts of data packets having a low duty factor, and

the RF transmitter is adapted to transmit bursts of modified data packets following transmission by the IR transmitter.

3. The device according to claim 1, further including an IR receiver and a RF receiver for receiving infrared and RF data transmitted thereto by an IR transmitter and RF transmitter, respectively.

4. The device according to claim 1, further including a motion sensor responsive to a motion sensor enable signal for producing a motion detect signal upon movement of the device, and

being responsive to a change in the device from motionless to moving for transmitting from an initial transmission rate to a higher transmission rate, and vice versa.

5. The device according to claim 1, further including an electrically conductive wire for attaching the device to an object or person and wherein the IR transmitter and RF transmitter are responsive to the wire being cut for transmitting a modified IR message and a modified RF message, respectively.

6. The device according to claim 1, further including at least one actuator button and wherein the IR transmitter and RF transmitter are responsive to the at least one actuator button being actuated for transmitting a respective IR actuation signal and RF actuation signal.

7. The device according to claim 5, further including an actuator button and wherein:

(a) the IR transmitter is responsive to the actuator button being actuated for transmitting an IR actuation signal,

(b) the RF transmitter is responsive to the actuator button being actuated for transmitting an RF actuation signal,

(c) cutting the wire and actuating the actuator button produce mutually distinctive status signals, thereby allowing a reader receiving the status signals to determine a cause thereof.

8. A reader including an IR receiver and an RF receiver for respectively receiving IR and RF data signals from a portable device having a respective IR transmitter and a respective RF transmitter as well as a respective IR receiver for tracking and location thereof, and being responsive to an IR data signal transmitted by the IR transmitter in the portable device within an enclosed zone for establishing said enclosed zone as the location of the portable device and for determining the location of the portable device based on a measured signal strength of the received RF signal if no IR data signal is received within a predetermined time window;

said reader being responsive to said IR data signal for sending an IR acknowledge signal for receipt by the IR receiver in the portable device so as to allow the portable device to disable the RF transmitter and being responsive to the RF data signal transmitted by the RF transmitter in the portable device after expiry of said predetermined time window for locating and tracking the portable device.

9. The reader according to claim 8, wherein the IR receiver and the RF receiver are coupled to a common output for feeding the IR signals and RF signals together to a communication device coupled to said common output.

10. A system for locating and tracking a portable device, said system comprising a portable communication device and a plurality of readers;

the portable communication device including a battery operated RF transmitter mounted in conjunction with an IR transmitter and an IR receiver allowing RF data to be transmitted and IR data to be transmitted and received said RF transmitter being adapted to transmit only if an IR data signal transmitted by the IR transmitter in the portable communication device is not acknowledged by the reader within a predetermined time window following transmission of the IR data signal, and

at least some of the readers including;

an IR receiver for receiving an IR data signal transmitted thereto by the IR transmitter in the portable communication device within an enclosed zone and being responsive to said IR data signal for establishing said enclosed zone as the location of the portable communication device, and

an IR transmitter responsive to said IR data signal for transmitting an IR acknowledge signal to the portable communication device within said predetermined time window following transmission of the IR data signal by the portable communication device;

at least one of the readers including an RF receiver for receiving an RF signal transmitted thereto by the RF transmitter in the portable communication device if no IR signal is received by the IR receiver therein within said predetermined time window following transmission of an IR data signal by the IR transmitter therein, and

an RF signal location unit coupled to the RF receiver for determining the location of the portable communication device based on a measured signal strength of the received RF signal.

11. The system according to claim 10, wherein:

the IR transmitter in the portable communication device is adapted to transmit bursts of data packets having a low duty factor, and

the RF transmitter in the portable communication device is adapted to transmit bursts of modified data packets following transmission by the IR transmitter.

12. The system according to claim 10, wherein each of the readers further includes:

an IR transmitter for transmitting IR data to the portable data communication device.

13. The system according to claim 10, wherein each of the readers further includes:

an output connection commonly connected to the IR receiver and the RF receiver for feeding the IR data and RF data together to a communication device coupled to said output connection.

14. The system according to claim 10, wherein each of the portable communication devices further includes a motion sensor responsive to a motion sensor enable signal for producing a motion detect signal upon movement of the device.

15. The system according to claim 14, wherein at least one of the readers is responsive to a change in the portable communication device from motionless to moving for transmitting from an initial transmission rate to a higher transmission rate, and vice versa.

16. The system according to claim 10, wherein the portable communication device further includes an electrically conductive wire for attaching the portable communication device to an object or person and wherein the IR transmitter and the RF transmitter therein are responsive to the wire being cut for transmitting a modified IR message and a modified RF message, respectively.

17. The system according to claim 10, wherein the portable communication device further includes at least one actuator button and wherein the IR transmitter and the RF transmitter therein are responsive to the at least one actuator button being actuated for transmitting respective IR and RF actuation signals.

18. The system according to claim 16, wherein the portable communication device further includes at least one an actuator button and wherein:

(a) the IR transmitter therein is responsive to the actuator button being actuated for transmitting an IR actuation signal,

(b) the RF transmitter therein is responsive to the actuator button being actuated for transmitting an RF actuation signal,

(c) cutting the wire and actuating the actuator button produce mutually distinctive status signals, thereby allowing one of the readers receiving the status signal to determine a cause thereof.

19. A method for using the system according to claim 10 to locate and track a portable communication device, the method comprising the steps of:

(a) mounting each of the readers in a respective enclosed space so that IR data received or transmitted by each of the readers is confined to the respective closed space,

(b) the IR transmitter in the portable communication device transmitting successive IR data pulses for reception by one of the IR readers,

(c) upon receipt of an IR data pulse by an IR receiver in one of the readers, said IR receiver sending an acknowledge signal to the portable communication device for reception by the IR receiver therein within a predetermined time window following transmission of said IR data pulse,

(d) upon no acknowledge signal being received by the IR receiver within the portable communication device within said time window, the RF transmitter in the portable communication device transmitting successive RF data pulses for reception by an RF receiver in one of the readers, and

(e) determining the location of the portable communication device from the respective closed space in which data transmitted thereby is received by the reader.

20. A method for using the system according to claim 10 to locate and track a portable communication device, the method comprising the steps of:

(a) mounting each of the readers in an open space so that IR data transmitted by the portable communication device may be received by more than one reader,

(b) the IR transmitter in the portable communication device transmitting successive IR data pulses for reception by one or more of the IR readers,

(c) upon receipt of an IR data pulse by the respective IR receiver in one or more of the readers determining a respective signal strength of each signal received by the respective IR receiver, and

(d) computing a location of the device based on the received signal strengths.

21. A method for communicating between a portable communication device including a battery-operated RF transmitter mounted in conjunction with an IR transmitter and an IR receiver and one or more IR readers and an RF reader, said method comprising the steps of:

(a) the IR transmitter transmitting successive IR data pulses for reception by one of the IR readers,

(b) upon receipt of an IR data pulse by one of the IR readers, said IR reader sending an acknowledge signal to the portable communication device for reception by the IR receiver therein within a predetermined time window following transmission of said IR data pulse,

(c) upon said acknowledge signal being received by the IR receiver within the portable communication device within said time window, the RF transmitter in the portable communication device being disabled,

(d) upon no acknowledge signal being received by the IR receiver within the portable communication device within said time window, the RF transmitter transmitting successive RF data pulses for reception by the RF reader, and

(e) repeating steps (a) to (d) in respect of subsequent data packets transmitted by the portable communication device.

22. The method according to claim 21, further including the steps of:

(d) determining a respective signal strength of each signal received by the IR and RF receivers, and

(e) computing a location of the device based on the received signal strengths.

23. A reader for receiving IR and RF signals from a portable device for tracking and location thereof, said reader including an IR transmitter allowing data to be transmitted by IR and an IR receiver and a RF receiver for receiving infrared and RF data transmitted thereto by an IR transmitter and RF transmitter, respectively and being responsive to the IR signal being transmitted within an enclosed zone for establishing said enclosed zone as the location of the portable device and for determining the location of the portable device based on a measured signal strength of the received RF signal if no IR signal is received within a predetermined time.

24. A method for locating and tracking a portable communication device having an IR transmitter and an IR receiver and an RF receiver using a plurality of readers each having an IR transmitter and an IR receiver and each having an RF receiver, the method comprising the steps of:

(a) mounting each of the readers in a respective enclosed space so that IR data received or transmitted by each of the readers is confined to the respective closed space,

(b) the IR transmitter in the portable communication device transmitting successive IR data pulses for reception by the respective IR receiver in one of the readers,

(c) upon receipt of an IR data pulse by an IR receiver in one of the readers, said IR receiver sending an acknowledge signal to the portable communication device for reception by the IR receiver therein within a predetermined time window following transmission of said IR data pulse,

(d) upon no acknowledge signal being received by the IR receiver within the portable communication device within said time window, the RF transmitter in the portable communication device transmitting successive RF data pulses for reception by the RF receiver in one of the readers,

(e) determining the location of the portable communication device from the respective closed space in which data transmitted thereby is received by the reader, and

(f) repeating steps (a) to (e) in respect of subsequent data packets transmitted by the portable communication device.

25. A method for locating and tracking a portable communication device having an IR transmitter and an IR receiver and an RF transmitter using a plurality of readers each having IR transmitter and an IR receiver and each having an RF receiver, the method comprising the steps of:

(a) mounting each of the readers in an open space so that IR data transmitted by the portable communication device may be received by more than one reader,

(b) the IR transmitter in the portable communication device transmitting successive IR data pulses for reception by one or more of the IR receivers in the respective readers,

(c) upon receipt of an IR data pulse by the respective IR receiver in one or more of the readers determining a respective signal strength of each signal received by the respective IR receiver,

(d) computing a location of the device based on the received signal strengths, and

(e) repeating steps (a) to (d) in respect of subsequent data packets transmitted by the portable communication device.