04-06-2013, 04:46 PM
Cut Detection in Wireless Sensor Network
Cut Detection.pptx (Size: 1.48 MB / Downloads: 58)
Introduction.
A Wireless Sensor Network (WSN) is basically a network of spatially distributed sensors used for monitoring physical/environmental conditions, such as motion, temperature, sound, vibration, pollutants, etc. and pass their data through the network to the main terminal for appropriate action.
WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors.
WHAT’S OUR PROBLEM:-
When sensor wants to send data to the source node has been
disconnected from the source node. Without the knowledge of
the network’s disconnected state, it may simply forward the data
to the next node in the routing tree, which will do the same to its
next node, and so on. However, this message wastes precious
energy of the nodes; the cut prevents the data from reaching the
destination. Therefore, on one hand, if a node were able to
detect the occurrence of a cut, it could simply wait for the
network to be repaired and eventually reconnected, which
saves on-board energy of multiple nodes and prolongs their
lives.
On the other hand, the ability of the source node to detect the
occurrence and location of a cut will allow it to undertake
network repair.
PROBLEM SOLUTION:-
Distributed algorithm to detect cuts, named the Distributed
Cut Detection (DCD) algorithm can serve as useful tools for
such network repairing methods. The algorithm allows each
node to detect DOS events and a subset of nodes to detect
CCOS events. The algorithm proposed is distributed and
Asynchronous.
It involves only local communication between neighboring
nodes, and is robust to temporary communication failure
between node pairs. A key component of the DCD algorithm
is a distributed iterative computational step through which the
nodes compute their (fictitious) electrical potentials.
The convergence rate of the computation is independent of
the size and structure of the network
CCOS Detection:-
The algorithm for detecting CCOS events relies on finding a short path around a hole. The method utilizes node states to assign the task of hole-detection to the most appropriate nodes. When a node detects a large change in its local state as well as failure of one or more of its neighbors, and both of these events occur within a (predetermined) small time
interval, the node initiates a PROBE message.
Each PROBE message p contains the following information:
1. A Unique probe ID.
2. Probe centroid Cp.
3. Destination node.
4. Path traversed (in chronological order), and
5. The angle traversed by the probe around the centroid
Conclusion.
The algorithm works effectively with a large classes of graphs of
varying size and structure, without requiring changes in the
parameters. For certain scenarios, the algorithm is assured to
detect connection and disconnection to the source node without error.
A key strength of the DCD algorithm is that the convergence rate of
the underlying iterative scheme is quite fast and independent of the
size and structure of the network.
Cut Detection.pptx (Size: 1.48 MB / Downloads: 58)
Introduction.
A Wireless Sensor Network (WSN) is basically a network of spatially distributed sensors used for monitoring physical/environmental conditions, such as motion, temperature, sound, vibration, pollutants, etc. and pass their data through the network to the main terminal for appropriate action.
WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors.
WHAT’S OUR PROBLEM:-
When sensor wants to send data to the source node has been
disconnected from the source node. Without the knowledge of
the network’s disconnected state, it may simply forward the data
to the next node in the routing tree, which will do the same to its
next node, and so on. However, this message wastes precious
energy of the nodes; the cut prevents the data from reaching the
destination. Therefore, on one hand, if a node were able to
detect the occurrence of a cut, it could simply wait for the
network to be repaired and eventually reconnected, which
saves on-board energy of multiple nodes and prolongs their
lives.
On the other hand, the ability of the source node to detect the
occurrence and location of a cut will allow it to undertake
network repair.
PROBLEM SOLUTION:-
Distributed algorithm to detect cuts, named the Distributed
Cut Detection (DCD) algorithm can serve as useful tools for
such network repairing methods. The algorithm allows each
node to detect DOS events and a subset of nodes to detect
CCOS events. The algorithm proposed is distributed and
Asynchronous.
It involves only local communication between neighboring
nodes, and is robust to temporary communication failure
between node pairs. A key component of the DCD algorithm
is a distributed iterative computational step through which the
nodes compute their (fictitious) electrical potentials.
The convergence rate of the computation is independent of
the size and structure of the network
CCOS Detection:-
The algorithm for detecting CCOS events relies on finding a short path around a hole. The method utilizes node states to assign the task of hole-detection to the most appropriate nodes. When a node detects a large change in its local state as well as failure of one or more of its neighbors, and both of these events occur within a (predetermined) small time
interval, the node initiates a PROBE message.
Each PROBE message p contains the following information:
1. A Unique probe ID.
2. Probe centroid Cp.
3. Destination node.
4. Path traversed (in chronological order), and
5. The angle traversed by the probe around the centroid
Conclusion.
The algorithm works effectively with a large classes of graphs of
varying size and structure, without requiring changes in the
parameters. For certain scenarios, the algorithm is assured to
detect connection and disconnection to the source node without error.
A key strength of the DCD algorithm is that the convergence rate of
the underlying iterative scheme is quite fast and independent of the
size and structure of the network.