Application routing protocol for wireless sensor networks

eggplantcinnabarMobile - Wireless

Nov 21, 2013 (3 years and 8 months ago)

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Application routing protocol for wireless sensor networks



W
ireless

sensor network

(WSN)

consisting of nodes with limited battery

power and wireless communications are deployed to collect

useful information from
the field
.

Sensor nodes typically contain a

sensor module, some sort of processing
element, and a wireless

interface module
.
The
traditional protocols

(DSR or DSDV)

try to minimize the end to end delay or maximize the throughput. So special routing
protocols are need for wireless networks. Routing
protocols in these networks are
required to provide tolerance to temporary or lasting faults in individual devices. So
the routing protocols proposed for sensor networks should provide the following
characteristics



Data
-
Centric



Energy efficient



Robustness
:


The existing routing protocols for sensor networks are

1.

Direct communication:

Every node will send their data directly to the base
station

(BS)

where the

end user

can

access

the data
. The advantage of this
protocol is that the information received at the

end
-
point is more accurate.
Since
the BS is located far away, the cost to transmit to the BS from any node is high
and nodes will die very quickly.
The lifetime of the network is very low.

2.

Minimum Transmission Energy (MTE) protocol:
In this protocol every

node
will find minimum energy path to the base station. Whenever it has information it
will send to the base station through this minimum energy path. The advantage is
lifetime of the network will be high compared to the direct communication.

3.

Sensor
Proto
cols for Information via Negotiation

(SPIN):

In SPIN, large data
messages are named using high
-
level data descriptors,

called meta
-
data. Nodes
use meta
-
data negotiation to eliminate the transmission of redundant

data
throughout the network. Allowing nodes

to base routing decisions on application
-
speci
fi
c

information about the data enables large energy
-
savings compared with
conventional approache
s.

4.

D
irected diffusion
:
In
directed di
ff
usion, data are named with

attribute
-
value
pairs, and interests for certai
n types of data are

disseminated throughout the
net
work. These interests di
ff
use to the correct area, setting up gradients that draw
events of interest

back to the node that originated the request. Good routes are
inherently reinforced, enabling low
-
energy

routing of the data. In addition, data
aggregation and caching can be performed within the

network, further reducing
node energy dissipation
.

5.

Power Efficient Gathering in Sensor Information Systems (PEGASIS):

Sensor data are diff
erent from the data assoc
iated with traditional wireless
networks in that it is not

the actual data itself that is important; rather, the analysis
of the data, which allows an end
-
user

to determine something about the
environment that is being
monitored, is the important result of

a sensor network
.

For example, if the sensors are monitoring an area for surveillance purposes, the

end
-
user does not need to see the data from all the individual sensors but does
need to know whether

or not there has been an intrusion in the area being
m
onitored.

Data

aggregation, also known as data

fusion, can combine several
unreliable data measurements to produce a more accurate signal by

enhancing the
common signal and reducing the uncorrelated noise.

Sending the aggregated data
to BS is energy effici
ent compared to direct communication.

PEGASIS is near optimal for this data gathering

application in sensor
networks. The key idea in
P
EGASIS is to

form a chain among the sensor nodes so
that each node will

receive from and transmit to a close neighbor. G
athered data

moves from node to node, get fused, and eventually a

designated node
, called
Leader of the chain,

transmits to the BS. Nodes take turns

transmitting to the BS
so that the average energy spent by each

node per round is reduced.

Every node
will
receive data from its neighbor aggregate with its own data and send it other
neighbor in the chain. The leader will send the overall aggregated data to BS. Here
we use Token ring
like structure for communication among the nodes. Leader will
have a master c
ontrol of the token. It will send the token to the end nodes. The
nodes which have the token control will send the data to closer neighbor along
with data.




My project includes the implementation of PEGASIS in network simulator
-
2
(NS
-
2) simulator and com
pares the results with Direct Communication and MTE
protocols.

The SPIN protocol implementation added a Resource
-
Adaptive Node to ns.
The new features of a Resource
-
Adaptive node are the Resources and the Resource
Manager. The Resource Manager provides a c
ommon interface between the
application and individual resources. The resources can be anything that needs to be
monitored, such as energy and node neighbors. The Application updates the status of
the node’s resources through the resource manager.

The impl
ementation include




Resource
-
adaptive node structure




Chain formation algorithm




Token transfer algorithm




Leader change




Data transfer mechanism




Base station node implementation




Implementation of direct and MTE protocols


The PEGASIS results ar
e compared with other two protocols in terms of
energy over time, number of nodes alive over time and the time at first node, half of
the nodes die.


PEGASIS will show a good results compared to the other protocols.

Simulation results show that PEGASIS ac
hieves great improvement over direct and
more robustness compared to MTE.