Transcript Energy Efficient Differentiable Coverage Service Protocol for

Energy Efficient Differentiable
Coverage Service Protocol for
Wireless Sensor Networks
H. Ozgur Sanli, Hasan Cam
Department of Computer Science and Engineering
Arizona State University
PerCom 2005
Outline
Introduction
Differentiable Coverage Service Protocols
NCP (Neighbor-Based Coverage Protocol)
GCP (Grid-Based Coverage Protocol)
Performance evaluation
Conclusions
Introduction
Sensor nodes are low-cost, lowpower, and multi-functional devices
Sensor nodes are deployed over
hostile or remote environments to
monitor a target area
Sensor nodes could monitor the whole
environment
The network lifetime is important
Introduction
C1
Dense deployment causes sensor nodes to
have highly overlapping sensing regions
that results in multiple nodes to generate a
packet and energy wastage will also
increase
Schedule the
C2
coverage of
neighboring sensor
A
nodes
C3
System model
Each sensor has equal sensing
range and transmission range
Each node has a unique identifier
and has its location information
Sensor network is deployed
randomly over the target region
NCP
(Neighbor-Based Coverage
Protocol)
Divide-and-conquer approach
Base case: ¼ of node’s sensing region
NCP
(Neighbor-Based Coverage
Protocol)
Coverage of the subregion
(1/4 *S)
R
B
A
C
Q
Two conditions satisfy full
coverage
At least one of the
neighbors should be
located in A
There should be at least
one neighbor in each of B
and C
NCP
(Neighbor-Based Coverage
Protocol)
rs
P(L)
B(L) B(R)
rs
Q(L)
P(R)
A(R)
A(L)
C(L)
C’(L)
O
C(R) Q(R)
C’(R)
Two neighboring
subregions among four
conditions for its full
coverage
At least one of the
neighbors should be
located in A(L)
There should be at least
one neighbor in each of C(L)
and either of B(L), B(R)
NCP
(Neighbor-Based Coverage
Protocol)
N2
P(R)
B(L) B(R)
M
A(L)
C(L)
N1 C’(L)
A(R)
N
N4
N
sleep
C(R)
C’(R) N3
Redundant node identification
GCP
(Grid-Based Coverage Protocol)
With the help of a virtual grid imposed on the
target area
O
rs/2
rs
GCP
(Grid-Based Coverage Protocol)
Redundant node identification
C
C
A
C
C
C
CC
C: existence of an awake
sensor node in the
neighboring grid unit slices
A: guarantees coverage of the
grid unit
priority
Protocol description
Use NCP or GCP
Going beyond minimum coverage
In some applications, the sensor
network should guarantee that any
point in the target region should be
covered by at least a given number
(α) of nodes.
Performance evaluation
power
Transmit power (Tx): 14.88mW
Receive power (Rx): 12.50mW
Idle power: 12.36mW
Sleep power: 0.016mW
100m * 100m square target region
Base station located on the upper left corner
of the target region
Fixed size 6 byte packets for communication
Simulation time: 10 rounds
each round: 10 sec.
Performance evaluation
Performance evaluation
Performance evaluation
Performance evaluation
Conclusions
Tow distributed coverage service
protocols are presented which keep
the sensing units of only a subset of
sensor nodes active to save energy
by identifying nodes redundant for
the desired coverage degree.
Thank you!!