Advanced embedded code hopping system

• US 5,872,519 A
• Filed: 04/20/1995
• Issued: 02/16/1999
• Est. Priority Date: 05/22/1992
• Status: Expired due to Term

• Current Assignee: Directed, LLC (VOXX International Corporation)
• Original Assignee: DEI Holdings Incorporated
• Inventors: Chen, Charles, Birchfield, Jerry W., Issa, Darrell E.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): WILSON JR, WILLIAM HALL
• Application Number:
  US08/425,597
• Time in Patent Office: 1,398 Days
• Field of Search: 380/37, 380/34, 380/9, 380/21, 380/23, 380/28, 380/25, 375/200, 375/205, 375/202, 370/18, 370/203, 340/825.3, 340/825.31, 340/825.34, 340/825.56, 340/825.69, 340/825.72
• US Class Current: 340/12.5
• CPC Class Codes: B60R 2025/1013 Alarm systems characterised by the type of warning signal, e.g. visual, audible
• CPC Class Codes: B60R 25/1003 Alarm systems characterised by arm or disarm features
• CPC Class Codes: B60R 25/1004 Alarm systems characterised by the type of sensor, e.g. current sensing means using door lock sensors B60R25/1001
• CPC Class Codes: B60R 25/1018 Alarm systems characterised by features related to the general power supply
• CPC Class Codes: B60R 25/104 characterised by the type of theft warning signal, e.g. visual or audible signals with special characteristics
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G07C 2009/00238 the transmittted data signal containing a code which is changed
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2009/00849 programming by learning
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/21 having a variable access code
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: G08B 13/1436 with motion detection
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• CPC Class Codes: G08B 25/018 Sensor coding by detecting magnitude of an electrical parameter, e.g. resistance
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: G08B 29/24 Self-calibration, e.g. compensating for environmental drift or ageing of components
• CPC Class Codes: G08B 29/26 by updating and storing reference thresholds
• CPC Class Codes: G08C 17/02 : using a radio link
• CPC Class Codes: G08C 19/22 : by varying the duration of individual pulses
• CPC Class Codes: G08C 19/28 : using pulse code
• CPC Class Codes: G08C 2201/51 : Remote controlling of devices based on replies, status thereof
• CPC Class Codes: G08C 2201/62 : Rolling code
• CPC Class Codes: H04J 13/0074 : Code shifting or hopping

Abstract

A system for monitoring and controlling an area comprising a controller for controlling system operational functions; at least one remote-control transmitter for transmitting system commands to the controller in a code word having a fixed word and a hopping word therein; the fixed word comprising at least one fixed data bit and the hopping word comprising at least one changing data bit, wherein the hopping word changes its binary value from transmission to transmission of the system commands; and, means for scrambling bits of the fixed word and bits of the hopping word within the code word.

Claims

1. A system for monitoring and controlling an area comprising:

a) a controller for controlling system operational functions;

b) at least one remote control transmitter for transmitting system commands to said controller in a code word having a fixed word and a hopping word therein;

c) said fixed word comprising at least one fixed data bit;

d) said hopping word comprising at least one changing data bit, wherein said hopping word changes its binary value from transmission to transmission of said system commands; and

,

e) a format word resident in said transmitter and said controller for respectively scrambling and descrambling said bits of said fixed word and said bits of said hopping word within said code word to generate a scrambled code word transmitted from said transmitter to said controller.

2. The system of claim 1 wherein said fixed word includes at least one bit therein and said hopping word includes a multiplicity of bits therein.

3. The system of claim 1 wherein said hopping word includes at least one bit therein and said fixed word includes a multiplicity of bits therein.

4. The system of claim 1 wherein said format word is programmed in said transmitter for scrambling said fixed bits and said hopping bits of said code word in a predefined arrangement.

5. The system of claim 1 wherein said format word is programmed within said transmitter and said controller for descrambling said code word received by said controller into said fixed and said hopping words.

6. The system of claim 1 further comprising a hopping algorithm for modifying said hopping word of said transmitter n-times in response to n-times activation of said transmitter and for modifying said hopping word m-times within said controller upon receipt of said code word m-times from said transmitter.

7. The system of claim 6 further comprising a learn mode for programming 0-time modified hopping word of said transmitter as a 0-time modified hopping word of said controller, thereby providing an initial match between said transmitter and said controller hopping words.

8. The system of claim 6 wherein said hopping algorithm modifies said hopping word of said transmitter and said hopping word of said controller.

9. The system of claim 6 wherein said hopping algorithm is a pointer to a look-up table containing a group of binary words therein, said look-up table programmed in both said transmitter and said controller.

10. The system of claim 6 further including:

a) calculating means for modifying said hopping word, received by said controller from said authorized transmitter, with said hopping algorithm (m+x)-times for comparison with said n-time modified hopping word received from said authorized transmitter if said n-time modified and said m-time modified hopping codes do not match; and

,

b) said controller storing said authorized transmitter hopping word if said hopping words do not match after performing said hopping algorithm (m+x) times.

11. The system of claim 1 further including:

a) an identification code particular to said transmitter transmitted within said code word; and

,

b) said controller storing said identification code for identification of said transmitter.

12. The system of claim 11 further including a memory for storing said identification code.

13. The system of claim 11 further including an electrically erasable and programmable read only memory for storing said identification code.

14. The system of claim 11 further comprising at least one authorized and at least one unauthorized remote control transmitter, each said transmitter having said particular identification code therein, for rejecting commands received by said controller from said unauthorized transmitters.

15. The system of claim 14 wherein said system command transmitted by said authorized transmitter is executed by said controller when said n-times modified hopping word transmitted by said transmitter and m-times modified hopping word of said controller are identical.

16. The system of claim 1 further including a transmission from said transmitter comprising a continuous series of said code words, said transmission initiated by activation of a switch integral to said transmitter and terminated by deactivation of said switch.

17. The system of claim 16 wherein said code words within said transmission are identical.

18. Method for monitoring and controlling an area comprising the steps of:

a) storing an initial hopping word within a remote control transmitter and a controller;

b) storing a fixed word within said remote control transmitter and said controller;

c forming a scrambled code word by using a format word to interlace bits from said fixed and said hopping words and transmitting said scrambled code word to said controller.

19. The method of claim 18 further including the step of defining said fixed code by multiplicity of bits.

20. The method of claim 18 further including the step of defining said hopping code by multiplicity of bits.

21. The method of claim 18 further including the steps of:

a) programming a format word within said remote control transmitter for scrambling said bits of said fixed and said hopping words into said code word;

b) scrambling said fixed and said hopping words of said code word and constructing said code word by sequentially shifting said fixed word bits into an output register for every logic one of said format word and sequentially shifting said hopping word bits into said output register for every logic zero of said format word.

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

a) programming said format word in said controller; and

,

b) descrambling said code word received by said controller by sequentially shifting bits of said received code word into fixed and hopping registers, wherein a bit is shifted into said fixed register of said controller if said format word bit logic value is one and into said hopping register of said controller if said format word bit value is a logic zero.

23. The method of claim 18 further including the steps of:

a) programming a hopping algorithm into said transmitter and said controller, each having a 0-times modified, initial hopping word therein;

b) modifying said initial hopping word n-times in response to n-times activation of said transmitter;

c) transmitting said n-times modified hopping word to said controller;

d) receiving said n-times modified hopping word within said controller; and

,

e) modifying said hopping word m-times in response to receipt of said code word m-times from said transmitter.

24. The method of claim 23 further including the steps of:

a) entering a learning mode of said transmitter and said controller; and

,

b) programming 0-time modified hopping word of said transmitter as a 0-time modified hopping word of said controller thereby providing an initial match between said transmitter and said controller hopping words.

25. The method of claim 23 further including the step of defining said hopping algorithm as a mathematical formula for mathematically modifying said hopping word of said transmitter and said hopping word of said controller.

26. The method of claim 23 further including the steps of:

a) defining said hopping algorithm as a pointer to a look-up table containing binary words therein; and

,

b) programming said look-up table in said transmitter and said controller.

27. The method of claim 23 further including the steps of:

a) modifying said hopping word, received by said controller from said authorized transmitter, with said hopping algorithm (m+x)-times for comparison with said n-time modified hopping word received from said authorized transmitter, if said n-time modified and said m-time modified hopping codes do not match; and

,

b) storing said authorized transmitter hopping word if said hopping words do not match after performing said hopping algorithm (m+x) times.

28. The method of claim 18 further including the steps of:

a) assigning an identification code particular to said transmitter transmitting said code word; and

,

b) programming said identification code particular to said transmitter into said controller for identification of said transmitter.

29. The method of claim 28 wherein the step of storing said identification code into said controller includes the step of storing said identification code in a memory device.

30. The method of claim 28 wherein the step of storing said identification code into said controller includes the step of storing said identification code in an electrically erasable and programmable read only memory.

31. The method of claim 28 further including the steps of:

a) recognizing said transmitter having said identification code as an authorized transmitter if said identification code is programmed in said controller;

b) recognizing said transmitter having said identification code as an unauthorized transmitter if said identification code is not programmed in said controller; and

,

c) rejecting commands received by said controller from said unauthorized transmitter.

32. The method of claim 31 further including the steps of:

a) receiving said code word, having said n-times modified hopping word therein, from said authorized transmitter;

b) performing said hopping algorithm on last received hopping word of said authorized transmitter;

c) comparing said n-times modified hopping word from said transmitter and m-times modified word of said controller; and

,

d) executing said system command transmitted by said authorized transmitter if said n-times modified hopping word and said m-times modified hopping word are identical.

33. The method of claim 18 further including the steps of:

a) activating said transmission from said transmitter by activating a switch integral to said transmitter;

b) continuously transmitting a continuous series of said code words from said transmitter to said controller; and

,

c) terminating said transmission by deactivation of said switch.

34. The method of claim 33 further including the step of transmitting identical code words within said transmission.