Electronic locating system for persons receiving telephone calls
First Claim
1. The method of determining the present location of a member of a defined class of individual units the present location of which is not known from among a large population of individual units, each programmed to respond to a predetermined inquiry signal, which are normally distributed throughout a defined facility comprising the steps of:
- receiving at a central station a request to establish the present location of one of said individual units;
establishing a two-way communication channel between said central station and a plurality of spaced relay stations, each relay station including a transmitter and a receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with infrared energy;
communicating by a message coded for selecting said one individual unit over said channel with said plurality of relay stations;
causing said relay stations to transmit an inquiry signal by said infrared energy and enabling the receiver of said one or more relay stations for a predetermined time period following each such transmission;
receiving the inquiry signal at each of said individual units that is located within the coverage of said one or more relay stations;
transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be the coded message to which it is programmed to respond;
receiving said acknowledgment signal at any of said relay stations within range of the radiant energy acknowledgment signal transmission;
transitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; and
utilizing at said central station any identification signal received from a relay station to determine the location of said relay station and hence the approximate location of the individual unit which transmitted said acknowledgment signal, said utilizing including, if more than one identification signal is received, repeating transmission of said inquiry signal at reduced signal level by any relay stations which responds with an identification signal to identify the relay station responsive to the lowest signal level.
1 Assignment
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Accused Products
Abstract
A method and system is disclosed for determining the location of a member of a class of individual transmitter-receiver units distributed throughout a defined facility. A central station establishes a two-way communication channel with one or more relay stations and sends a coded message identifying a particular individual unit over the communication channel. The relay stations respond to the message by sending out wake-up signals and radiant energy inquiry signals. The individual unit identified in the inquiry signal responds with a radiant energy acknowledgment signal. Embodiments of the invention disclose the use of infrared energy or ultrasonic energy for the radiant energy. Ultrasonic signals are sent on a plurality of frequencies. The relay stations send identification signals to the central station which identify the sending relay station and indicate whether an acknowledgment signal was received. The central station determines the approximate location of the individual unit from the identification signals.
According to one feature of the invention, the relay stations are divided into groups in which each relay station of a group covers an area distinct from the areas covered by the remaining relay stations of the same group. In this arrangement the central station can communicate with one group of relay stations at a time.
225 Citations
33 Claims
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1. The method of determining the present location of a member of a defined class of individual units the present location of which is not known from among a large population of individual units, each programmed to respond to a predetermined inquiry signal, which are normally distributed throughout a defined facility comprising the steps of:
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receiving at a central station a request to establish the present location of one of said individual units; establishing a two-way communication channel between said central station and a plurality of spaced relay stations, each relay station including a transmitter and a receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with infrared energy; communicating by a message coded for selecting said one individual unit over said channel with said plurality of relay stations; causing said relay stations to transmit an inquiry signal by said infrared energy and enabling the receiver of said one or more relay stations for a predetermined time period following each such transmission; receiving the inquiry signal at each of said individual units that is located within the coverage of said one or more relay stations; transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be the coded message to which it is programmed to respond; receiving said acknowledgment signal at any of said relay stations within range of the radiant energy acknowledgment signal transmission; transitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; and utilizing at said central station any identification signal received from a relay station to determine the location of said relay station and hence the approximate location of the individual unit which transmitted said acknowledgment signal, said utilizing including, if more than one identification signal is received, repeating transmission of said inquiry signal at reduced signal level by any relay stations which responds with an identification signal to identify the relay station responsive to the lowest signal level. - View Dependent Claims (2, 3, 4, 5, 6, 9)
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7. The method of determining the present location of a member of a defined class of individual units, each programmed to respond to a predetermined inquiry signal, from among a large population of individual units which are normally distributed throughout a defined facility comprising the steps of:
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receiving at a central station a request to establish the present location of one of said individual units; establishing a two-way communication channel between said central station and one or more of a plurality of spaced relay stations, each relay station including a transmitter and receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with infrared energy; selectively communicating by a coded message over said channel with said one or more of said plurality of relay stations; causing said one or more relay stations to transit an inquiry signal by said infrared energy and enabling the receiver of said one or more relay stations for a predetermined time period following each such transmission; receiving the inquiry signal at each of said individual units that is located within the coverage of said one or more relay stations; transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be a signal to which it is programmed to respond; receiving said acknowledgment signal at any of said one or more relay stations within range of the radiant energy acknowledgment signal transmission; transmitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; upon said central station receiving an identification signal from a plurality of relay stations, determining the responding relay station closest to an individual unit by repeated further steps of modifying the coded message communicated over said channel by including within the message a command to lower the sensitivity of the relay station receiver and causing said plurality of relay stations to lower the sensitivity of their respective receivers; and utilizing at said central station the identification signal of the last relay station whose response is received after one or more reductions in sensitivity of the relay station receivers to determine the location of said last relay station and hence the approximate location of the individual unit which transmitted said acknowledgment signal.
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8. The method of determining the present location of a member of a defined class of individual units from among a large population of individual units, each programmed to respond to a predetermined inguiry signal, which are normally distributed throughout a defined facility comprising the steps of:
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receiving at a central station a request to establish the present location of one of said individual units; establishing a two-way communication channel between said central station and one or more of a plurality of spaced relay stations, each relay station including a transmitter and a receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with infrared energy; selectively communicating by a coded message over said channel with said one or more of said plurality of relay stations; causing said one or more relay stations to transmit an inquiry signal by said infrared energy and enabling the receiver of said one or more relay stations for a predetermined time period following each such transmission; receiving the inquiry signal at each of said individual units that is located within the coverage of said one or more relay stations; transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be a signal to which it is programmed to respond; receiving said acknowledgment signal at any of said one or more relay stations within range of the radiant energy acknowledgment signal transmission; transmitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; upon said central station receiving an identification signal from a plurality of relay stations, determining the responding relay station closest to an individual unit by repeated further steps of modifying the coded message communicated over said channel by including within the message a command to reduce the power of the relay station transmitter and causing said plurality of relay stations to reduce the power of their respective transmitters; and utilizing at said central station the identification signal of the last relay station whose response is received after one or more reductions of the relay stations transmitter power to determine the location of said last relay station and hence the approximate location of the individual unit which transmits said acknowledgment signal.
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10. The method of determing the present location of a member of a defined class of individual units the present location of which is not known from among a large population of individual units each programmed to respond to a predetermined inquiry signal which are normally distributed throughout a defined facility comprising the steps of:
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receiving at a central station a request to establish the present location of one of said individual units; establishing a two-way communication channel between said central station and at least one plurality of groups of spaced relay stations, each relay station including a transmitter and a receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with radiant energy the detectable signal level from relay stations of different groups overlapping thereby substantially eliminating dead zones but wherein each relay station of a group covers an area which does not overlap with a detectable signal the areas covered by each of the other relay stations in the same group; communicating by a coded message over said two-way communication channel with each of said groups of relay stations in sequence; causing all of the relay stations of each said group in said sequence to transmit an inquiry signal by said radiant energy and enabling the receivers of the respective group relay stations for a predetermined time period following each such transmission; receiving the inquiry signal at each of said individual units that is located within the coverage of any of the relay stations; transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be a signal to which it is programmed to respond; receiving said acknowledgment signal at a receiver of any of said relay stations that is enabled and is within range of the radiant energy acknowledgment signal transmission; transmitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; and utilizing at said central station a first identification signal received from a first group relay station to determine the location of said first group relay station and hence the approximate location of the individual unit which transmitted said acknowledgment signal;
said utilizing including identifying the relay station of a second group if a second identification signal is received whereby said approximate location is determined to be within the overlap area covered by the responding first and second group relay stations. - View Dependent Claims (11, 12, 13)
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14. A communication and locating system that operates within a defined facility comprising:
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a plurality of individual transmitter-receiver units each of said units including means programmed to be responsive to a predetermined radiant energy inquiry signal and including means for transmitting a radiant energy acknowledgment signal in response to receiving said predetermined inquiry signal to which it is programmed to respond; a plurality of groups of relay stations located so as to be cumulatively capable of substantially covering said facility with transmissions of radiant energy at detectable signal level for said units and in which each relay station of a group covers an area that is distinct from the areas covered by each of the other relay stations in the same group, each of said relay stations including means for transmitting the radiant energy inquiry signal to said individual units in response to coded meassages, said inquiry signals containing information indentifying a particular individual unit whose location is sought; a central station including means for establishing a two-way communication channel between said central station and a plurality of said relay stations and for communicating by a coded meassage sequentially with said relay stations one group at a time over said channel, said coded message identifying the particular individual unit to be identified in the inquiry signal; each of said relay stations including means operable after receiving said coded message for receiving an acknowledgment signal from said individual units and sending an indentification signal over said communication channel to said central station, said identification signal identifiying the sending relay station and indicating whether an acknowledgment signal was received by said sending relay station; and said central station further including means for receiving any identification signals from said relay stations and determining therefrom the approximate location of any particular individual unit responding to said coded message whereby a single response identifies said location as the area covered by the responding relay station and more than one response identifies said location as the overlap area covered by the responding relay stations. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A communication and locating sytem comprising:
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a control station; a plurlaity of relay stations each covering an identified space within the area covered by said system; and a badge station for each individual to be located by the system; said control station comprising; means for entering coded information identifying a person receiving an incoming call; a non-active memory storing data identifying likely locations of the persons to be located by the system; means responsive to entry of person-identifying data for searching said memory for the likely location of the person identified by said data entry; means for communicating a transmission request to one or more of said relay stations selected to be in communication with the likely locations of the person identified; and receiving means for receiving an identification signal from a relay station that has received an acknowledgment signal from a badge station, said identification signal identifying the location of the particular relay station that received the acknowledgment signal; said relay stations each comprising; means for receiving said transmission request from said control station; means responsive to receiving said transmission request for radiating a coded inquiry signal into the particular identified space covered by said relay station; means for receiving a radiated acknowledgment signal from a badge station within said identified space and developing a located response that indicates whether an acknowledgment signal was received; and means for transmitting said located response in said identification signals to said receiving means in said control station; said badge stations each comprising; coded responsive radiation receiving means for detecting said coded inquiry signal individual to a particular badge from a local relay station; and radiation transmitting means responsive to a detected coded inquiry signal for originating an acknowledgment radiating signal back to the local relay station; said control station including; means for identifying the number for placing a telephone call to a telephone set located near the location of the badge station which originated said acknowledgment signal; and means operable upon failure to obtain an acknowledgment signal from the relay stations selected at the likely location of the person identified for repeating the transmission request in time sequence to selected relay stations until each said particular identified space has been radiated with said coded inquiry signal without simultaneous time and space overlap of signals in any said identified space to produce unambiguous response from the local relay stations nearest said badge station originating an acknowledgment signal. - View Dependent Claims (26, 27, 28, 29, 30, 32)
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31. A communication and locating system comprising:
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a control station; a plurality of relay stations each covering an identified space within the area covered by said system; and a badge station for each individual to be located by the system; said control station comprising; means for entering coded information identifying a person receiving an incoming call; a memory storing data identifying likely locations of the persons to be located by the system; means responsive to entry of person-identifying data for searching said memory for the likely location of the person identified by said data entry; means for communicating a transmission request to one or more of said relay stations selected to be in communication with the like locations of the person identified; and receiving means for receiving an identification signal from a relay station that has received an acknowledgment signal from a badge station, said identification signal identifying the location of the particular relay station that received the acknowledgment signal; said relay stations each comprising; means for receiving said transmission request from said control station; means responsive to receiving said transmission request to radiate a coded inquiry signal into the particular identified space covered by said relay station; means for receiving a radiated acknowledgment signal from a badge station within said identified space and developing a located respnse that indicates whether an acknowledgment signal was received; and means for transmitting said located response in said identification signals to said receiving means in said control station; said badge stations each comprising; coded responsive radiation receiving means for detecting said coded inquiry signal individual to a particular badge, from a local relay station; and radiation transmitting means responsive to a detected coded inquiry signal for originating an acknowledgment radiating signal back to the local relay station; said control station including; means for identifying the number for placing a telephone call to a telephone set located near the location of the badge station which originated said acknowledgment signal; and means, operable upon failure to obtain an acknowledgment signal from the relay stations selected at the likely location of the person identified, for repeating the transmission request in time sequence to all relay stations, wherein said identified spaces covered by said system include spaces having a plurality of relay stations with partially overlapping coverage and said control station includes means responsive to multiple response from the same badge station via plural different location relay stations for reducing the signal detection sensitivity of said plural relay stations to select the relay station receiving the strongest badge originated signal.
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33. The method of determining the present location of a member of a defined class of individual units the present location of which is not known from among a large population of individual units, each programmed to respond to a predetermined inquiry signal, which are normally distributed throughout a defined facility comprising the steps of:
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receiving at a central station a request to establish the present location of one of said individual units; establishing a two-way communication channel between said central station and a plurality of spaced relay stations, each relay station including a transmitter and a receiver and said relay stations being located so as to be cumulatively capable of substantially covering said facility with infrared energy; communicating by a message coded for selecting said one individual unit over said channel with said plurality of relay stations; causing said relay stations to transmit an inquiry signal by said infrared energy and enabling the receiver of said relay stations for a predetermined time period following each such transmission; receiving the inquiry signal at each of said individual units that is located within the coverage of said one or more relay stations; transmitting a radiant energy acknowledgment signal from any individual unit which recognizes the inquiry signal received from a relay station to be the coded message to which it is programmed to responde; receiving said acknowledgment signal at any of said relay stations within range of the radiant energy acknowledgment signal transmission; transmitting to said central station over said channel from any relay station which receives said acknowledgment signal an identification signal which identifies that relay station; and utilizing at said central station any identification signal received from a relay station to determine the location of said relay station and hence the approximate location of the individual unit which transmitted said acknowledgment signal, said utilizing including repeating, if more than one identification signal is received, transmission of said inquiry signal by any relay stations which respond with an identification signal and reducing the sensitivity of the radiant energy receivers of said any relay stations to identify the relay station responsive to the lowest signal level.
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Specification