METHOD AND APPARATUS FOR COLLABORATIVE SENSING BASED ON AN ALLOWED ERROR RANGE OF A SENSOR IN A WIRELESS SENSOR NODE

• US 20100118786A1
• Filed: 11/12/2009
• Published: 05/13/2010
• Est. Priority Date: 11/11/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Choi, Hyo-Hyun, RYU, Je-Hyok
• Granted Patent: US 8,045,511 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H04W 40/08 based on transmission power
• CPC Class Codes: H04W 40/10 based on available power or energy
• CPC Class Codes: H04W 40/16 based on interference

Abstract

A method and an apparatus for transmitting sensor data by using AER sensing and collaborative sensing in order to increase the energy efficiency in a wireless sensor network. The method includes calculating an AER for each of said at least one sensor using sensor data measured from said at least one sensor and sensor profile information corresponding to said at least one sensor, and determining sensor data to be transmitted to a higher node from among sensor data provided by the sensor module based on the AER.

Claims

1. A sensor node of a wireless sensor network, the sensor node comprising:

a sensor module including at least one sensor, the sensor module outputting sensor data measured by said at least one sensor; and

an Allowed Error Range (AER) sensing block for calculating an AER for each of said at least one sensor using sensor data measured from said at least one sensor and sensor profile information corresponding to said at least one sensor, and for determining sensor data to be transmitted to a higher node from among sensor data provided by the sensor module, based on the AER.

2. The sensor node of claim 1, wherein the AER sensing block comprises:

a Range Calculator Module (RCM) for calculating the AER for each of said at least one sensor using the sensor data provided from the sensor module and the sensor profile information corresponding to said at least one sensor; and

a bounded sensing module for determining the sensor data to be transmitted to the higher node from among the sensor data provided by the sensor module, based on the AER.

3. The sensor node of claim 1, wherein the AER sensing block determines an upper limit of the AER by adding sensor data measured by a predetermined sensor from among said at least one sensor to a specific allowed error within sensor profile information corresponding to the predetermined sensor, and determines a lower limit of the AER by subtracting the specific allowed error from the sensor data measured by the predetermined sensor.

4. The sensor node of claim 1, wherein the AER sensing block determines an upper limit of the AER by adding a minimum value of multiple sensor data values measured by a predetermined sensor from among said at least one sensor to a specific allowed error within sensor profile information corresponding to the predetermined sensor, and determines a lower limit of the AER by subtracting the specific allowed error from a maximum value of the multiple sensor data values measured by the predetermined sensor.

5. The sensor node of claim 1, wherein the AER sensing block determines sensor data beyond the AER from among the sensor data measured by said at least one sensor as the sensor data to be transmitted to the higher node, and determines predetermined sensor data among the sensor data measured by said at least one sensor during a preset time period, when sensor data beyond the AER does not exist during the preset time period.

6. The sensor node of claim 5, wherein the AER sensing block re-calculates the AER using the determined sensor data.

7. A method of transmitting sensor data by a sensor node including a sensor module having at least one sensor and an Allowed Error Range (AER) sensing block, in a wireless sensor network, the method comprising:

calculating, by the AER sensing block, an AER for each of said at least one sensor by using sensor data measured from said at least one sensor and sensor profile information corresponding to said at least one sensor; and

determining sensor data to be transmitted to a higher node from among sensor data provided by the sensor module based on the AER.

8. The method of claim 7, wherein calculating the AER comprises:

calculating an upper limit of the AER by adding sensor data measured by a predetermined sensor from among said at least one sensor to a specific allowed error within sensor profile information corresponding to the predetermined sensor; and

calculating a lower limit of the AER by subtracting the specific allowed error from the sensor data measured by the predetermined sensor.

9. The method of claim 7, wherein calculating the AER comprises:

Calculating an upper limit of the AER by adding a minimum value of multiple sensor data values measured by a predetermined sensor from among said at least one sensor to a specific allowed error within sensor profile information corresponding to the predetermined sensor; and

calculating a lower limit of the AER by subtracting the specific allowed error from a maximum value of the multiple sensor data values measured by the predetermined sensor.

10. The method of claim 7, further comprising:

determining, by the AER sensing block, sensor data beyond the AER from among the sensor data measured by said at least one sensor as the sensor data to be transmitted to the higher node; and

determining predetermined sensor data among the sensor data measured by said at least one sensor during a preset time period, when sensor data beyond the AER does not exist during the preset time period.

11. The method of claim 10, further comprising re-calculating the AER using the determined sensor data.

12. A sensor network comprising:

multiple child nodes, each of the multiple child nodes including at least one sensor and transmitting sensor data measured by said at least one sensor; and

a parent node for receiving the sensor data transmitted from the multiple child nodes, for managing information on the multiple child nodes, for determining a child node in a collaborative active state, to which sensor data measured by a same sensor from among child nodes having the same sensor will be transmitted, for determining a child node in a collaborative sleeping state, to which the sensor data measured by the same sensor will not be transmitted, from child nodes having the same sensor by using the information on the multiple child nodes, and for controlling transmission of the sensor data measured by the same sensor to each of the determined child nodes.

13. The sensor network of claim 12, wherein the multiple child nodes are in a relation of 1-hop to the parent node.

14. The sensor network of claim 12, wherein the parent node comprises:

a collaborative list manager module for receiving the information on the multiple child nodes, managing a collaborative list for each of the child nodes, and determining if there is a child node requiring help;

a collaborative sensor selection module for selecting a child node that will help the child node that needs help, based on the collaborative list; and

a sensor state manager module for changing state information of the child node requiring help and the child node that will help, and providing the changed state information of the child nodes to the collaborative list manager module.

15. The sensor network of claim 14, wherein the collaborative list comprises one of:

a node IDentification (ID);

a sensor ID;

sensor data;

a sensor node state (s_state);

a sensed time stamp (t_stamp);

a sensor'"'"'s own allowed error (s_err);

a battery state (energy_level); and

a degree of adjacency between 1-hop child nodes (nearF).

16. The sensor network of claim 15, wherein the collaborative sensor selection module selects the child node that will help, by using the degree of the adjacency between the 1-hop child nodes (nearF).

17. The sensor network of claim 12, wherein the child node in the collaborative active state transmits sensor data beyond a predetermined AER from among the sensor data measured by the same sensor to the parent node or transmits the sensor data measured by the same sensor to the parent node when a preset time has passed.

18. The sensor network of claim 17, wherein the child node in the collaborative active state calculates the predetermined AER by using sensor profile information corresponding to the same sensor and sensor data measured by the same sensor.

19. The sensor network of claim 12, wherein, when sensor data is received from the child node in the collaborative sleeping state, the parent node updates a sensor node state corresponding to the child node having transmitted the sensor data to an active state in the information on the multiple child nodes.

20. A method of transmitting sensor data in a wireless sensor network including multiple child nodes and a parent node, the method comprising:

determining, by the parent node, a child node in a collaborative active state, to which sensor data measured by a same sensor from among child nodes having a same sensor will be transmitted, and a child node in a collaborative sleeping state, to which sensor data measured by the same sensor will not be transmitted, from the child nodes having the same sensor by using information on the child nodes; and

controlling transmission of sensor data measured by the same sensor to each of the child nodes having the same sensor based on the determining.

21. The method of claim 20, further comprising receiving the information on the child nodes from a plurality of child nodes that are in a relation of 1-hop.

22. The method of claim 20, further comprising receiving, from the child node in the collaborative active state, sensor data beyond a predetermined AER from among sensor data measured by the same sensor or the sensor data measured by the same sensor, when a preset time has passed.

23. The method of claim 22, wherein the predetermined AER is calculated using sensor profile information corresponding to the same sensor and the sensor data measured by the same sensor.

24. The method of claim 20, further comprising, when sensor data is received from the child node in the collaborative sleeping state, updating a sensor node state corresponding to the child node having transmitted the sensor data to an active state in the information on the multiple child nodes.