Information Technology Reference
In-Depth Information
An n-dimensional vector
REQ= (req
1
, req
2
, ···, req
n
)
denotes requirements of
tasks, where
req
i
denotes requirement of task
t
i
. Through the dynamic topology and
routing control, sink node can obtain energy of node and ability of task of node.
In this paper, a matrix
B
k
=
(
b
ij
)
l×m
is used to record the capacity of different coali-
tion on different tasks, and we defined the execution time as:
req
i
Time
ij
=
(2)
b
ij
Where
b
ij
denotes the capacity that
i
-th coalition executes
j
-th task,
Time
ij
denotes the
time required where
j
-th task run in
i
-th coalition.
The energy consumption of wireless sensor networks includes three parts: transmis-
sion energy consumption, processing power consumption and access to energy con-
sumption. As the energy of transferring 1 bit data is far greater than the energy of
processing 1 bit data, we usually ignore the processing energy consumption and the
access to energy consumption. The discussion focused on communication energy
consumption in this paper. The minimum transmission energy consumption is
P
0,trans
when the standard distance is
d
0
i.e., the distance
d
ij
between
i
-th node and
j
-th node
determines the energy consumption [13]:
2
d
2
dG
πβ
(4
)
ij
P
=×
×
P
(3)
i trans
,
o trans
,
2
2
λ
0
t
r
Where,
G
t
denotes emission coefficient,
G
r
denotes receive coefficient,
λ
denotes
Wireless communication wavelength,
β
denotes Factor of the energy consumption
of the system. As (
4π
)
2
ʲ/G
t
G
r
λ
2
×P
0,trans
is a constant, (
d
ij
/d
0
)
2
is the evaluation index
of unit data of transmission energy. To simplify the data, a matrix
COST= (cost
ij
)
m×l
is
used to record transmission energy consumption,
cost
ij
denotes the energy consump-
tion when
j
-th task transfer data to
i
-th coalition.
This paper use an n-dimensional vector E to denotes residual energy of coalition.
e
i
denotes residual energy of
i
-th coalition.
P(e
i
)
denotes the proportion of residual ener-
gy of
i
-th coalition in the sum of residual energy of entire network.
l
()
(4)
Pe
=
e
e
i
i
i
i
=
1
In order to prolong the network lifetime, during the process of allocation, we
should balance the residual energy of each coalition. The network residual energy
average degree is defined as:
l
()
()
Pe
H
=−
P e
log
i
(5)
i
i
=
1
Where denotes the energy entropy of networks. The larger the value of entropy, the
more average residual energy distribution, and the longer network lifetime.
