Personal messaging system and method

• US 5,973,613 A
• Filed: 11/17/1997
• Issued: 10/26/1999
• Est. Priority Date: 06/15/1990
• Status: Expired due to Term

• Current Assignee: OL Security LLC (Intellectual Ventures LLC)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Verma, Vikram, Reis, Robert Steven
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US08/971,597
• Time in Patent Office: 708 Days
• Field of Search: 340/825.54, 340/825.44, 340/825.31, 340/825.34, 340/572.1, 340/573.1, 340/573.4
• US Class Current: 340/7.23
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10059 transponder driven
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles

Abstract

A pager device received paging messages. The user reads a paging message, selects one of a set of stored, predetermine reply messages, and transmits the selected reply message from the pager. The reply signal is received by one of a set of local cellular receivers, which sends the received signal to a computer for interpretation. The computer initiates an action based on interpretation of the received reply signal. The communication system communicates with large numbers of pagers in a time and energy efficient manner. The pagers are associated with items located in a communication region that is interrogated by an interrogator on a one-to-many basis using broadcast commands, on a one-to-one basis using directed commands or on a combination basis using both methods. Messaging occurs through organized transmission and reception of signals between the pagers and the interrogator. A batch collection protocol uses a combined one-to-many and one-to-one communication system that effectively resolves communication contentions. The batch collection protocol employs a plurality of collection periods which communicate with large or unknown numbers of portable pagers.

Claims

1. A communication system for communicating in a communication region comprising,

an interrogator including:

an interrogator memory for storing interrogator sequencing code including a broadcast command and a directed command,

an interrogator processor connected for accessing said interrogator memory and for processing said interrogator sequencing code to sequence said broadcast command and said directed command,

an interrogator transceiver connected to said interrogator processor for sending and receiving communications in said communication region over a common communication channel including sending said broadcast command and said directed command,

a plurality of pagers dispersed within the communication region, each of said pagers including;

a pager transceiver for sending and receiving communications including a page signal to and from said interrogator transceiver over said common communication channel,

a pager memory for storing information including pager sequencing code and a set of predefined reply messages operable to be selected for transmission by a user of said pager,

a paper processor, connected to said paper transceiver to receive said broadcast command and said directed command, for processing said pager sequencing code to send a response to said interrogator through said pager transceiver and for transmitting one of said set of predefined reply messages as a reply signal,

whereby two or more of said plurality of pagers dispersed within the communication region may each send a response over said common communication channel during the same time period such that at some times a collision of responses occurs and such that at other times no collision of responses occurs,

wherein said broadcast command requests pager ID'"'"'s from all pagers,

for each pager, said pager processor sends a pager ID with said response upon receipt of said broadcast command, and

for each pager for which said interrogator receives a pager ID, said interrogator processor sends said directed command to acknowledge that said pager ID has been received,

wherein each of said pagers has a unique pager ID and said interrogator collects the pager ID'"'"'s from pagers in the communication region using communications between said interrogators and said pagers during a plurality of collection periods, said interrogator having in said interrogator code,

synchronizing code for sending synchronizing signals to said pagers to initiate each of said collection periods,

bandwidth code for controlling the bandwidth of said collection periods, each said pager having means for inhibiting sending a pager ID after receipt of one of said directed commands.

2. The communication system of claim 1 wherein said interrogator establishes said collection periods as collection periods CP(1), CP(2), . . . , CP(p), . . . , CP(P) having respectively listen periods LP(1), LP(2), . . . , LP(p), . . . , LP(P) and having respectively acknowledge periods AP(1), AP(2), . . . , AP(p), . . . , AP(P).

3. The communication system of claim 2 wherein said bandwidth code sets the bandwidth of each collection period by setting the duration of the respective listen period.

4. The communication system of claim 3 wherein for one or more subsequent listen periods after the first listen period LP(1), the listen periods are shorter in duration than the listen period LP(1).

5. The communication system of claim 4 wherein said first listen period LP(1) and said one or more subsequent listen periods each have durations that permit receipt of separate transmissions of pager IDs from a plurality of pagers.

6. The communication system of claim 5 wherein for a plurality of said one or more listen periods, each successive listen period is approximately one-half the duration of the preceding listen period.

7. The communication system of claim 5 wherein for said listen periods, each of said pagers has response means for distributing the pager ID to a particular response time during the respective listen period.

8. The communication system of claim 7 wherein said particular response time is determined for each said pager by a hash table algorithm using the pager ID for said pager.

9. The communication system of claim 7 wherein said particular response time is randomly determined for each said pager using a randomizing element to generate said particular response time.

10. The communication system of claim 1 wherein said pagers have sleep and awake modes and said interrogator collects messages from said pagers in the communication region using communications between said interrogators and said pagers during a collection period,

said interrogator having in said interrogator sequencing code,

wake-up code for sending a wake-up signal to said pagers,

synchronizing code for sending a synchronizing signal to said pagers to initiate a collection period,

each said pager having a controllable power gate for providing power to said pager transceiver in a low-power state and in a normal-power state where said pager processor controls said power gate to select said normal-power state in response to said wake-up signal, and each said pager having in said pager sequencing code,

code for controlling the sleep mode in the low-power state in response to said directed command from said interrogator,

code for sensing said synchronizing signal if said pager is in said awake mode,

code for sending said response to said interrogator in response to a synchronizing signal from said interrogator if said pager is in the awake mode.

11. The communication system of claim 1 wherein each of said pagers includes a controllable power means for providing power to said pager transceiver in a low-power state for a sleep mode and in a normal-power state for an awake mode where said pager processor controls said power means to select said low-power state or said normal-power state.

12. The communication system of claim 11 wherein,

said broadcast command requests all pagers but one specific pager to go to said sleep mode,

for each pager except said one specific pager, said pager processor upon receipt of said broadcast command causes said pager to go to said sleep mode,

for said specific pager, said interrogator processor sends said directed command to command an action by said specific pager,

said pager processor for said specific pager upon receipt of said directed command sends said response including the pager ID to said interrogator.

13. The communication system of claim 11 wherein said interrogator includes wake-up means for sending a wake-up signal to said pagers and wherein said pager processor is responsive to said wake-up signal from said interrogator for switching to said normal-power state.

14. The communication system of claim 11 wherein said pager transceiver in each of said pagers includes,

a radio frequency transmitter,

a radio frequency receiver,

an antenna connected to said transmitter and receiver.

15. A communication system for communicating in a communication region comprising,

an interrogator including:

an interrogator memory for storing interrogator sequencing code including a broadcast command and a directed command,

an interrogator processor connected for accessing said interrogator memory and for processing said interrogator sequencing code to sequence said broadcast command and said directed command,

an interrogator transceiver connected to said interrogator processor for sending and receiving communications in said communication region over a common communication channel including sending said broadcast command and said directed command,

a plurality of pagers dispersed within the communication region, each of said papers including;

a pager transceiver for sending and receiving communications including a page signal to and from said interrogator transceiver over said common communication channel,

a pager memory for storing information including pager sequencing code and a set of predefined reply messages operable to be selected for transmission by a user of said pager,

a pager processor, connected to said pager transceiver to receive said broadcast command and said directed command, for processing said pager sequencing code to send a response to said interrogator through said pager transceiver and for transmitting one of said set of predefined reply messages as a reply signal,

whereby two or more of said plurality of pagers dispersed within the communication region may each send a response over said common communication channel during the same time period such that at some times a collision of responses occurs and such that at other times no collision of responses occurs,

wherein said broadcast command requests pager ID'"'"'s from all pagers,

for each pager, said pager processor sends a pager ID with said response upon receipt of said broadcast command, and

for each pager for which said interrogator receives a pager ID, said interrogator processor sends said directed command to acknowledge that said pager ID has been received,

wherein each of said pagers has a unique pager ID and said interrogator collects the pager ID'"'"'s from pagers in the communication region using communications between said interrogators and said pagers during a plurality of collection periods, said interrogator having in said interrogator code,

synchronizing code for sending synchronizing signals to said pagers to initiate each of said collection periods,

bandwidth code for controlling the bandwidth of said collection periods, each said pager having means for inhibiting sending a pager ID after receipt of one of said acknowledge signals and for sending a pager ID only once for each collection period.

16. A communication system for communicating in a communication region comprising,

an interrogator including:

an interrogator memory for storing interrogator sequencing code including a broadcast command and a directed command,

an interrogator processor connected for accessing said interrogator memory and for processing said interrogator sequencing code to sequence wherein said broadcast command and said directed command,

an interrogator transceiver connected to said interrogator processor for sending and receiving communications in said communication region over a common communication channel including sending said broadcast command and said directed command,

a plurality of pagers dispersed within the communication region, each of said pagers including;

a pager transceiver for sending and receiving communications including a page signal to and from said interrogator transceiver over said common communication channel,

a pager memory for storing information including pager sequencing code and a set of predefined reply messages operable to be selected for transmission by a user of said pager,

a pager processor, connected to said pater transceiver to receive said broadcast command and said directed command, for processing said pager sequencing code to send a response to said interrogator through said pager transceiver and for transmitting one of said set of predefined reply messages as a reply signal,

whereby two or more of said plurality of pagers dispersed within the communication region may each send a response over said common communication channel during the same time period such that at some times a collision of responses occurs and such that at other times no collision of responses occurs,

wherein said interrogator transceiver includes,

a plurality of polarization diverse and spatially diverse transceivers, each transceiver including,

an antenna,

a radio frequency transmitter connected to said interrogator processor to provide output signals to said antenna for transmission to said pagers,

a radio frequency receiver connected to said antenna to receive signals from said pagers to provide input signals to said interrogator processor,

signal strength detection means for detecting the signal strength of the signals received at each of said receivers from said pagers and for providing a signal strength indication to said interrogator processor from each of said receivers,

said interrogator processor connected to a switch to select for each of said pagers the transceiver having the receiver providing the highest signal strength.

17. A communication system for communicating in a communication region comprising,

an interrogator including:

an interrogator memory for storing interrogator sequencing code including a broadcast command and a directed command,

an interrogator processor connected for accessing said interrogator memory and for processing said interrogator sequencing code to sequence said broadcast command and said directed command,

an interrogator transceiver connected to said interrogator processor for sending and receiving communications in said communication region over a common communication channel including sending said broadcast command and said directed command,

a plurality of pagers dispersed within the communication region, each of said pagers including;

a pager transceiver for sending and receiving communications including a page signal to and from said interrogator transceiver over said common communication channel,

a pager memory for storing information including pager sequencing code and a set of predefined reply messages operable to be selected for transmission by a user of said pager,

a pager processor, connected to said pager transceiver to receive said broadcast command and said directed command, for processing said pager sequencing code to send a response to said interrogator through said pager transceiver and for transmitting one of said set of predefined reply messages as a reply signal,

whereby two or more of said plurality of pagers dispersed within the communication region may each send a response over said common communication channel during the same time period such that at some times a collision of responses occurs and such that at other times no collision of responses occurs,

wherein said pagers have sleep and awake modes and said interrogator collects messages from said pagers in the communication region using communications between said interrogators and said pagers during a collection period,

said interrogator having in said interrogator code,

synchronizing code for sending a synchronizing signal to said pagers to initiate said collection period,

each said pager having in said pager sequencing code,

mode code for controlling the sleep mode and awake mode of the pager processor,

sensing code for sensing said synchronizing, signal if said pager is in said awake mode,

send code for sending said response to said interrogator in response to said synchronizing signal from said interrogator if said pager is in the awake mode,

wherein said pager processor includes an interrupt input for interrupting pager processor operation, and wherein said system includes a unit connected to said pager processor interrupt input for providing an interrupt signal for signaling the presence of said broadcast command from said unit, and wherein said mode code is responsive to said interrupt signal to cause said pager to be in the awake mode.

18. The communication system of claim 17 wherein said pager processor sends said response to said interrogator and wherein said interrogator processor after receipt of said response sends an acknowledge signal to said pager.

19. The communication system of claim 18, wherein said acknowledge signal causes said pager to be in the sleep mode.

20. The communication system of claim 18, wherein said acknowledge signal is a directed command.

21. The communication system of claim 17 wherein said pager processor includes a reset input and a unit connected to said reset input for providing a reset signal for signaling the presence of a wake-up signal from said interrogator, and wherein said mode code is responsive to said wake-up signal to cause said pager to be in the awake mode.