Sensor web

• US 7,133,800 B2
• Filed: 10/08/2003
• Issued: 11/07/2006
• 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.
• Primary Examiner(s): Assouad, Patrick J.
• Application Number:
  US10/682,308
• Publication Number:
  US 20040128091A1
• Time in Patent Office: 1,126 Days
• Field of Search: None
• US Class Current: 702/125
• 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 having wireless communication capability;

a second Sensor pod, at a second location, and having wireless communication capability 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; and

a plurality of additional sensor pods, each having wireless communication capability, where each of said first and second sensor pods communicates information wirelessly to all of said additional sensor pods that are within range of the wireless communication.

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 wirelessly 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 wirelessly synchronized to said master clock.

5. 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 wirelessly among said first and second Sensor pods and also to a plurality of additional sensor pods, such that all of said sensor pods within a range of wireless communications, wirelessly receive information about all of the parameters sensed at each of the spaced locations; and

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

6. A method as in claim 5 further comprising:

Wirelessly 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.

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

8. A method as in claim 6 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.

9. A method as in claim 6, wherein said wirelessly synchronizing comprises first, at a first time, designating one of said sensor pods to be a master clock, and synchronizing all sensor pods to said one of said sensor pods, and second, at a second time, designating another of said sensor pods tube be a master clock, and then synchronizing all sensor pods to said another sensor part.