Methods and apparatus for coverage verification in a wireless sensor network

1. A method, comprising:

obtaining an estimate of a distance between a first node in a wireless sensor network and each of a plurality of additional nodes within a transmission radius of said first node;

determining a relative location of each of said plurality of additional nodes with respect to a coordinate system of said first node;

identifying border segments of a sensing border of said first node, wherein each of said border segments comprises a section of the sensing border of said first node that is covered by a sensing radius of at least one of said additional nodes; and

determining whether a plurality of said border segments forms a cyclic segment sequence for said first node.

2. The method of claim 1 , further comprising the step of determining whether a coverage hole exists based on the step of determining of whether said plurality of border segments forms said cyclic segment sequence for said first node.

3. The method of claim 2 , wherein said step of determining whether said coverage hole exists further comprises the step of determining if a k-coverage hole exists, where k is greater than one.

4. The method of claim 1 , further comprising providing said estimated distances to each of said plurality of additional nodes.

5. The method of claim 1 , wherein said coordinate system comprises r-map coordinates of said first node and said additional nodes, where r is based on said transmission radius of said first node, and wherein said r-map coordinates specify said relative locations of each of said plurality of additional nodes in an r-vicinity of said first node.

6. The method of claim 5 , wherein said relative location of each of said plurality of additional nodes in said r-vicinity of said first node is represented by a pair <d u,v , θ u,v >, where d u,v is a radial coordinate indicating a distance between said first node and a corresponding one, v, of said additional nodes and θ u,v is an angular coordinate of said corresponding one, v, of said additional nodes denoting a direction of said one, v, of said additional nodes relative to an arbitrary polar-axis.

7. The method of claim 1 , wherein said coordinate system comprises an arbitrary polar axis and an angular coordinate for each of said plurality of additional nodes within said transmission radius.

8. The method of claim 1 , wherein said cyclic segment sequence comprises a sequence of said border segments, wherein each of said border segments overlaps with at least two other border segments.

9. The method of claim 1 , further comprising the step of estimating a size of a coverage hole.

10. The method of claim 1 , wherein said first node is an internal node in said wireless sensor network.

11. The method of claim 1 , wherein said transmission radius of said first node is at least twice a sensing radius of said first node.

12. An apparatus, comprising:

a sensing node for a wireless sensor network, the node being configured to:

obtain an estimate of a distance between a first node in a wireless sensor network and each of a plurality of additional nodes within a transmission radius of said first node;

determine a relative location of each of said plurality of additional nodes with respect to a coordinate system of said first node;

identify border segments of a sensing border of said first node, wherein each of said border segments comprises a section of the sensing border of said first node that is covered by a sensing radius of at least one of said additional nodes; and

determine whether a plurality of said border segments forms a cyclic segment sequence for said first node.

13. The apparatus of claim 12 , wherein the sensor node is further configured to determine whether a coverage hole exists based on the step of determining of whether said plurality of border segments forms said cyclic segment sequence for said first node.

14. The sensor node of claim 12 , wherein said sensor node is further configured to determine if a k-coverage hole exists, where k is greater than one.

15. The sensor node of claim 12 , wherein said sensor node is further configured to provide said estimated distances to each of said plurality of additional nodes.

16. The sensor node of claim 12 , wherein said cyclic segment sequence comprises a sequence of said border segments, wherein each of said border segments overlaps with at least two other border segments.

17. The sensor node of claim 12 , wherein a processor is further configured to estimate a size of a coverage hole.

18. The sensor node of claim 12 , wherein said sensor node is an internal node in said wireless sensor network.

19. An article of manufacture, comprising a non-transitory computer readable storage medium encoding one or more machine-executable programs of instructions that perform the steps of:

obtaining an estimate of a distance between a first node in a wireless sensor network and each of a plurality of additional nodes within a transmission radius of said first node;

determining a relative location of each of said plurality of additional nodes with respect to a coordinate system of said first node;

identifying border segments of a sensing border of said first node, wherein each of said border segments comprises a section of the sensing border of said first node that is covered by a sensing radius of at least one of said additional nodes; and

determining whether a plurality of said border segments forms a cyclic segment sequence for said first node.

20. The article of claim 19 , wherein the steps further comprise determining whether a coverage hole exists based on the step of determining of whether said plurality of border segments forms said cyclic segment sequence for said first node.