Title: Energy Efficient Data Gathering Algorithms in Sensor Networks
1Energy Efficient Data Gathering Algorithms in
Sensor Networks
2What is a Sensor Network?
- Sensor networks mainly constitute of inexpensive
sensors densely deployed for data collection from
the field in a variety of scenarios - A sensor node is an autonomous device with
integrated sensing, processing, and communication
capabilities
3Data gathering in Sensor Network
- A typical application in sensor network is
gathering sensed data at a distant base station.
- Each sensor node has power control and the
ability to transmit data to any other sensor node
or directly to the BS. - In each round of this data gathering application,
all data from all nodes need to be collected and
transmitted to the BS, where the end user can
access the data
4The difficulties in collect and transmit data in
Sensor Network
- Each node transmits its data directly to the Base
Station? Not suggested - BS is usually far away from sensors
- such communication will be a high cost
- and drain the power quickly
- 2. Sensor's battery is not replaceable, and
sensors may operate in hostile or remote
environments - Energy consumption is considered as the most
important concern in sensor network
5Approaches for Data Gathering
6Direct Approach
- Each sensor sends its data directly to the base
station - quickly drain the battery of the nodes and reduce
the system lifetime - the only receptions in this protocol occur at the
base station - Only the base station is close to nodes, or the
energy required to receive data is large, direct
approach may be an acceptable (and possibly
optimal) method of communication
7MTE Based Approach
- Nodes route data to the Base Station through
intermediate nodes - Intermediate nodes act as routers for other
nodes data and work as sensing nodes as well - Intermediate nodes are chosen if and only if the
transmit amplifier energy is minimized
8Clustering Based Approach
- Nodes are organized into groups, or say clusters
- Each cluster has a cluster head
- Other nodes in the same cluster sends data to its
cluster head - Cluster heads transmit the data to the Base
Station - Only cluster heads can send data to the Base
Station
9Clustering Based Approach (Continue)
- Static Dynamic Clustering Approach
- The difference is the way to choose cluster heads
- Static Clustering Approach has a fixed cluster
heads - Dynamic Clustering Approach has dynamic cluster
heads
10Clustering Approach An Example (Continue)
All nodes marked with the same symbol belong to
the same Cluster and the cluster-head nodes are
marked with a ?.
11Chain Based Approaches
- Each node receives from and transmits to close
neighbours and takes turns being the leader for
transmission to the Base Station - Assumed that all nodes have global knowledge of
the network and employ the greedy algorithm - Starts with the furthest node from the BS to
ensure that nodes farther from the Base Station
have close neighbours - Data gathering is performed in rounds. In each
round, each node receives data from one
neighbour, fuses with its own data, and transmits
to the other neighbour on the chain
12Chain Based Approaches An Example
node c(2) is the leader. Node c(0) will pass its
data to node c(1). Node c(1) fuses node c(0)s
data with its own and then transmits to the
leader. Node c(3) and c(4) do the same thing.
Node c(2) waits to receive data from both
neighbours c(1) and c(3) and then fuses its
data with its neighbours data. Finally, node
c(2) transmits one message to the BS
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14Energy-Efficient Data Gathering with Multiple
Paths
15Multiple Path Construction Mechanism
16Data Forwarding Mechanism
17AN EXAMPLE SCENARIO
18Performance evaluation Environment
- NS 2 Simulation
- 200 Nodes
- 1000 m x 1000 m Area
- Each simulation runs for 300 Seconds
- Each Node transmission range 250 m
- CBR 40 Bytes Sized Traffic
- Energy at Each Node 10 J
- Energy Transmitting Data 0.6W
- Energy Receiving Data 0.3 W
19Parameters Compared
- Experiment 1
- Comparison EDGM with AODV
- a Throughput
- b Nodal Life
- Experiment 2
- Energy Saving not considered.
- Random Selection Technique was considered.
- a Nodal Life in Dense Network,
- b Nodal Life in Sparse Network.
-
20Throughput EDGM vs. AODV
21Nodal Life EDGM vs. AODV
22Nodal Life Dense Network
23Nodal Life Sparse Network
24Conclusion
- Energy consumption is considered as the most
important concern. - It is hard to say which approach we point in this
paper is the best one. We only choose the
approach fitting for the particular case. - Should talk more about there NS 2 Simulation
should include Energy Equations if any included. - Static and Dynamic nodes evaluation should be
included.