Sensor web

• US 20040128091A1
• Filed: 10/08/2003
• Published: 07/01/2004
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Delin, Kevin A., Jackson, Shannon P.
• Granted Patent: US 7,133,800 B2
• Time in Patent Office: Days
• US Class Current: 702/75
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H04J 3/0641 Change of the master or reference, e.g. take-over or failure of the master
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

a Sensor Web formed of a number of different sensor pods. Each of the sensor pods include a clock which is synchronized with a master clock so that all of the sensor pods in the Web have a synchronized clock. The synchronization is carried out by first using a coarse synchronization which takes less power, and subsequently carrying out a fine synchronization to make a fine sync of all the pods on the Web. After the synchronization, the pods ping their neighbors to determine which pods are listening and responded, and then only listen during time slots corresponding to those pods which respond.

Claims

1. A Sensor Web, comprising:

a first Sensor pod at a first location, sensing a specified parameter at said first location at a specified time; and

a second Sensor pod, at a second location, and in communication with said first Sensor pod, sensing a value of the same specified parameter at said second location, different than said first location.

2. A web as in claim 1, wherein said first and second Sensor pods each include clocks therein, and wherein said first and second Sensor pods each sense said same parameter at the same instant.

3. A web as in claim 2, wherein said clocks of said first and second Sensor pods are synchronized.

4. A web as in claim 1, wherein said first Sensor pod forms a mother pod having a master clock therein, and said second Sensor pod has a timebase that is synchronized to said master clock.

5. A method, comprising:

synchronizing a plurality of spaced Sensor pods such that said spaced Sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced Sensor pods to determine a parameter at times that are based on said synchronized clock.

6. A method as in claim 5, wherein said using comprises causing said sensor pods to each determine the parameter at substantially precisely the same time but at different locations.

7. A method as in claim 5 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

8. A method as in claim 5, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

9. A method as in claim 8, wherein each of said sensor pods has an identifier, and each of said sensor pods communicates during a parameter sensing routine at a specified time slot.

10. A method as in claim 9, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods respond to pings, and time slots assigned to said other sensor pod, and listening only during said time assigned to said other sensor pods exist.

11. A method as in claim 5, further comprising sharing data between the plurality of sensor pods, such that each of the sensor pods receives data from each other Sensor pod.

12. A method as in claim 11, further comprising, in each of the sensor pods, processing the data from the plurality of sensor pods, to determine information from the data.

13. A method as in claim 12, wherein the information from the data is vector information related to a value of parameters sensed at different locations.

14. A method as in claim 5, further comprising adding another Sensor pod to the Sensor Web during operation of the Sensor Web.

15. A method as in claim 14, wherein said another Sensor pod is a Sensor pod with a different hardware configuration then the at least one other Sensor pod in the web.

16. A method as in claim 14, further comprising, after adding said another Sensor pod, synchronizing a clock within said another Sensor pod with the rest of the web.

17. A method as in claim 16, wherein said synchronizing comprises synchronizing in a single duty cycle.

18. A method as in claim 17, wherein said synchronizing comprises carrying out a first, coarse synchronization at reduced power consumption, and subsequently carrying out a second, fine synchronization, at a higher power consumption.

19. A method as in claim 5, further comprising using said synchronized time base to carry out a main processing loop in each of said plurality of sensor pods which both starts and ends at substantially the same time.

20. A method as in claim 5, wherein said plurality of sensor pods are each assigned a time slot within a time base, and each communicate with other sensor pods during said time slot within said time base.

21. A method as in claim 5, further comprising using said Sensor Web for security.

22. A method as in claim 5, further comprising using said Sensor Web for agriculture.

23. A method, comprising:

carrying out an operation at each of a plurality of spaced Sensor pods collectively forming a Sensor Web;

communicating among the plurality of spaced sensor pods, which each of the spaced Sensor pods communicating using a different parameter;

polling among a plurality of different parameters, to determine a collection of which of the sensor pods are using each said different parameter; and

communicating using only ones of said different parameters which have been detected by said polling.

24. A method as in claim 23, wherein said carrying out an operation comprises sensing a sensed value, using a sensor pod in each of said spaced sensor pods.

25. A method as in claim 23, wherein said parameter is a time slot and using said synchronized clock to synchronize said spaced Sensor pods to determine a parameter at times that are based on said synchronized clock.

26. A method as in claim 25, wherein said using comprises causing said sensor pods to each determine the sensed value at precisely the same time but at different locations based on said synchronized clock.

27. A method as in claim 25 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

28. A method as in claim 25, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the sensed values sensed at each of the spaced locations.

29. A method as in claim 25, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods exist, and their time slots for communication, and listening for communication only during time slots where the sensor pods exist.

30. A method as in claim 25, further comprising sharing data between the plurality of sensor pods, such that each of the sensor pods receives data from each other Sensor pod.

31. A method as in claim 30, further comprising processing the data from the plurality of sensor pods, to determine information from the data.

32. A method as in claim 31, wherein the information from the data is vector information related to a value of parameters to sensed at different locations.

33. A method as in claim 25, further comprising adding another Sensor pod to the Sensor Web during operation of the Sensor Web.

34. A method as in claim 33, wherein said another Sensor pod is a Sensor pod with a different hardware configuration then at least one other Sensor pod in the web.

35. A method as in claim 33, further comprising, after adding said another Sensor pod, the synchronizing a clock within said another Sensor pod with said synchronized clock.

36. A method as in claim 35, wherein said synchronizing comprises carrying out a first, course synchronization at reduced power consumption, and subsequently carrying out a second, fine synchronization, at a higher power consumption.

37. A method as in claim 23, further comprising using said synchronized time base to carry out a main processing loop in each of said plurality of sensor pods which both starts and ends at substantially the same time.

38. A method as in claim 23, wherein said plurality of sensor pods are each assigned a time slot within a time base, and each communicate with other sensor pods during said time slot within said time base.

39. A method as in claim 23, further comprising using said Sensor Web for security.

40. A method as in claim 23, further comprising using said Sensor Web for agriculture.

41. A method, comprising:

deploying a plurality of sensor pods having a specified hardware characteristic;

activating said sensor pods to carry out a specified operation at each of a plurality of spaced locations; and

evolving the Sensor Web by adding more sophisticated sensor pods which have an additional hardware characteristic by and said specified hardware characteristic.

42. A method as in claim 41, further comprising:

synchronizing said plurality of spaced Sensor pods such that said spaced Sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced Sensor pods to determine a parameter at times that are based on said synchronized clock.

43. A method as in claim 42, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time but at said different locations.

44. A method as in claim 42 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

45. A method as in claim 42, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

46. A method as in claim 42, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods exist, and time slots during which said sensor pods communicate, and listening only during said time slots during the sensor pods exist.

47. A method as in claim 42, further comprising sharing data between the plurality of sensor pods, such that each of the sensor pods receives data from each other Sensor pod.

48. A method as in claim 47, further comprising processing the data from the plurality of sensor pods in the sensor pods, to determine information from the data.

49. A method as in claim 48, wherein the information from the data is vector information related to a value of parameters to sensed at different locations.

50. A method as in claim 42, further comprising adding another Sensor pod to the Sensor Web during operation of the Sensor Web.

51. A method as in claim 50, further comprising, after adding said another Sensor pod, the synchronizing a clock within said another Sensor pod with said synchronized clock.

52. A method as in claim 42, wherein said synchronizing comprises carrying out a first, coarse synchronization at reduced power consumption, and subsequently carrying out a second, fine synchronization, at a higher power consumption.

53. A method as in claim 42, further comprising using said synchronized time base to carry out a main processing loop in each of said plurality of sensor pods which both starts and ends at substantially the same time.

54. A method, comprising:

deploying a plurality of sensor pods, which have an internal time base, to measure a specified parameter;

synchronizing said time bases among said plurality of sensor pods; and

using the synchronized time base to measure said specified parameter in each of said plurality of sensor pods, at a synchronized time.

55. A method as in claim 54, wherein said synchronized time is precisely the same moment.

56. A method as in claim 54, further comprising using said synchronized time base to carry out a main processing loop in each of said plurality of sensor pods which both starts and ends at substantially the same time.

57. A method as in claim 54, wherein said plurality of sensor pods are each assigned a time slot within a time base, and each communicate with other sensor pods during said time slot within said time base.

58. A method as in claim 54 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

59. A method as in claim 54, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

60. A method as in claim 59, wherein each of said sensor pods has an identifier, and each of said sensor pods communicates during a parameter sensing routine at a specified time slot.

61. A method as in claim 59, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods exist, and time slots during the existing sensors communicate, and listening only during times of the existing sensors.

62. A method as in claim 54, further comprising sharing data between the plurality of sensor pods, such that each of the sensor pods receives data from each other Sensor pod.

63. A method as in claim 62, further comprising processing the data from the plurality of sensor pods, to determine information from the data.

64. A method as in claim 63, wherein the information from the data is vector information related to a value of parameters to sense at different locations.

65. A method as in claim 54, further comprising adding another Sensor pod to the Sensor Web during operation of the Sensor Web.

66. A method as in claim 65, wherein said another Sensor pod is a Sensor pod with a different hardware configuration then the at least one other Sensor pod in the web.

67. A method as in claim 65, further comprising, after adding said another Sensor pod, the synchronizing a clock within said another Sensor pod with said synchronized time base.

68. A method as in claim 54, further comprising using said synchronized time base to carry out a main processing loop in each of said plurality of sensor pods, which both starts and ends at substantially the same time.

69. A method, comprising:

using a plurality of sensor pods at a plurality of different locations to sense parameters at said plurality of different locations; and

forming vector information from said parameters from the plurality of sensor pods.

70. A method as in claim 69, further comprising synchronizing said plurality of Sensor pods such that said Sensor pods each include a synchronized clock;

and

using said synchronized clock to synchronize said spaced Sensor pods to determine parameters at times that are based on said synchronized clock.

71. A method as in claim 69, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time but at different locations to determine said vector information.

72. A method as in claim 69 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said clocks while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said clock.

73. A method as in claim 69, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations and said forming vector information is carried out in each of the sensor pods.

74. A method as in claim 73, wherein each of said sensor pods has an identifier, and each of said sensor pods communicates during a parameter sensing routine at a specified time slot.

75. A method as in claim 74, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods exist, and their time slots, and listening only during time slots corresponding to the sensor pods which exist.

76. A method, comprising:

maintaining a plurality of sensor pods in a power managed state where the sensor pods turn on at each of a specified interval of time to sense parameters at said specified interval of time; and

commanding that said specified interval of time be changed, for each of said plurality of sensor pods, using a single command.

77. A method as in claim 76, further comprising:

synchronizing said plurality of Sensor pods such that said Sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced Sensor pods to determine a parameter at times that are based on said synchronized clock.

78. A method as in claim 77, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time but at different locations.

79. A method as in claim 77 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

80. A method as in claim 77, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

81. A method as in claim 80, wherein each of said sensor pods has an identifier, and each of said sensor pods communicates during a parameter sensing routine in a specified time slot.

82. A method as in claim 81, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods exist, and their time slots, and listening only during times that the sensor pods exist.

83. A method, comprising:

sensing a parameter at a first Sensor pod which controls an operation;

sensing the parameter at a second Sensor pod, at a different location then said first Sensor pod;

sharing information among said Sensor pods; and

commanding, from said second Sensor pod, said first Sensor pod to carry out said operation.

84. A method as in claim 83 further comprising:

synchronizing a plurality of spaced Sensor pods such that said spaced Sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced Sensor pods to determine a parameter at times that are based on said synchronized clock.

85. A method as in claim 84, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time but at different locations.

86. A method as in claim 84 wherein said synchronizing comprises first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power, and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

87. A method as in claim 84, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

88. A method, comprising:

first, coarsely synchronizing a Sensor pod to a master clock, using a coarse synchronization operation;

second, after said coarsely synchronizing, finely synchronizing said Sensor pod to said master clock using a fine synchronization operation, where said fine synchronization takes more power then said coarse synchronization.

89. A method, comprising:

synchronizing a plurality of spaced Sensor pods such that said spaced Sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced Sensor pods to carry out a processing routine at times that are based on said synchronized clock.

90. A method as in claim 89, wherein said carry out comprises taking a measurement.

91. A method as in claim 89, wherein said carry out comprises exiting a main loop of a processing routine.

92. A method as in claim 89, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time but at different locations.

93. A system comprising:

a plurality of sensor pods, each having an assigned address, each of said plurality of sensor pods including a memory therein, said memory storing a list of which sensor pods responded to a ping operation, and each sensor pod including a controllable receiver which turns on only during time slots corresponding to values in said memory which represent which of the plurality of sensor pods turned on during the ping operation.

94. A method, comprising:

deploying a plurality of sensor pods separately;

carrying out a communication operation between said sensor pods to synchronize internal clocks of said sensor pods; and

communicating among said sensor pods by causing each Sensor pod to communicate during a different time slot within the Sensor pod.

95. A method, comprising:

sensing data in each of a plurality of Sensor pods which are in communication with one another;

sending the data from the Sensor pods using a specified command packet, including information sensed by the Sensor pod receiving the data; and

if an amount of data from a first Sensor pod is more than can fit in said packet, then forming a virtual pod, associated with the first Sensor pod, in a specified form, that produces a virtual pod packet only includes data.

96. A method as in claim 95, further comprising synchronizing clocks among said plurality of sensor pods, such that said sensor pods operate with a synchronized clock.

97. A method as in claim 96, wherein said command packet is sent during a specified time slot.