basic information about WSN and node deploy and lifetime

1. 1
Wireless Sensor Network
Lifetime Constraints
Musaab M. Jasim
Yildiz university
Computer department

2. 2
Outline
 Introduction of WSN.
 Generic energy consumption of WSN .
 WSN Deployments
 Deterministic deployment .
 Random deployment .
 WSN Routing Protocols
 WSN Routing Strategies .
 Routing Protocols in WSNs.
 Energy- Efficient Routing Protocol Algorithms
 LEACH (Low Energy Adaptive Clustering Hierarchy).
 DECSA (Distance-Energy Cluster Structure Algorithm).
 Conclusion .

3. 3
Introduction of WSN

4. Introduction of WSN
The convergence of the Internet, communications, and information technologies,
coupled with recent engineering advances, is paving the way for a new generation
of inexpensive sensors and actuators, capable of achieving a high order of spatial
and temporal resolution and accuracy and this generation of devices led to widely
distribution of the Wireless Sensor Network (WSN) in recent years . WSNs have
become a subject of interest for many different applications .
A wireless sensor network is an infrastructure comprised of large numbers of nodes
which involve sensing (measuring), computing, and communication elements that
gives an administrator the ability to instrument, observe, react to events and
phenomena in a specified environment where these nodes are deployed. These
nodes fall in two types
(1) sensor node which gather the sensing data and direct it to
(2) sink node which be interested for this data .
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5. Introduction of WSN
the both types of nodes are limited in their power resources because it usually run
on batteries and this imposes a hard limit on the lifespan of a WSN especially for
large-scale WSNs when it integrate with other networks .
To maximize the lifetime of WSN , we need to comprehend some important aspects
,such as : how the power of nodes is consumed in general form , what the influence
of the nodes deployment ways on the node's power is , and the major role of
routing protocol on manage the WSNs and minimize the energy consumption.
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6. 6
Generic energy consumption
of WSN

7. Generic energy consumption of WSN.
 The major energy consumption of a node (usually in free rectangular area)
includes the energy which is consumed for:
1. message reception .
2. message transmission .
3. event sensing.
 The energy for event sensing is generally linearly proportional to the time period
of operation and is assumed to be
 The energy for message reception depends only on the number of received
messages.
 the energy dissipation for transmitting a message to a receiver with a distance
(d) away being
 the energy dissipation for receiving a message is
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is the average power consumption.
is a time interval.
L(d) denotes the propagation loss in DB
L(d0)
the propagation loss at a reference
distance
Β
k
the path loss exponent
sensing message bits
Eelec energy consumption by the
electronic circuit

8. 8
WSN Deployments

9. WSN Deployments
 Deployment is application dependent process which concerned with
setting up an operational sensor network in a real-world environment to
provide completely area coverage with different levels of nodes density
and take into account that each sensor has a probability (P) to be active
and it can be cover a circular region centered at itself with radius (r) ,
There are two major sorts of deployment are distinguished in WSNs :
1. Deterministic deployment the deployment method in which the nodes of WSN are
distributed in a structured way by putting them in pre-planned positions. There are
many models of this deployment such as :
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B- Grid-based deployment
A- Linear-based deployment .
 Square Grid

10. WSN Deployments
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B- Grid-based deployment
 Equilateral Triangle grid
Deployment
 Tri-Hexagon Tiling (THT).
2. Random deployment The deployment methods in which the nodes of WSN are
randomly distributed over the desired area by, e.g., dropping them out of an
helicopter as in the volcano monitoring system or in a hostile environment .
It may be a one-time activity where the installation and use of a sensor network are
strictly separate actions. Or, it may be a continuous process, with more nodes being
deployed at any time during the use of the network . there two types of random
deployment :

11. WSN Deployments
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Random deployment types
II. Non-uniform random deploymentI. Uniform random deployment
• It deployment of WSN nodes in different
density level over the entire sensing
area ,where all nodes in the network
are homogeneous with the same
available energy .
• It attempts to balance the
communication load of each sub-region.
• It is considered as the solution of the
“Energy Holes problem” , where
nodes are deployed with a high density
on a location with high energy
consumption, whereas, a low density
for a location with low energy
consumption .
• It is deployment of WSN nodes in
randomly fashion with the same
density over the entire sensing area,
where all nodes are homogeneous with
the same available energy .
• It can achieve the best network
sensing coverage in the initial phase.
• It suffers from the “Energy Holes
problem” , where nodes located at an
area with high energy consumption will
run out of available energy and die off
quickly .

12. WSN Deployments
12
Models
Non-uniform random deployment
Rectangle model
Uniform random deployment
Coronas Model
where the desired sensing area is assumed
to be a rectangle with length L and width W,
i.e. the area is A = L × W. and the data sink is
assumed to be beside an edge of the
sensing area as base-station, and the sensor
node deploy in non-uniform random way with
sensing radius is R and available sensing
area is πR2.
A message transmitted from corona Ci is
forwarded by sensor nodes in coronas Ci−1,
Ci−2, and so on until it reaches corona C1
from where it is transmitted to the sink which
reside in the center. Corona width is chosen
such that a message is forwarded by only
one sensor in each corona.

13. 13
WSN Routing Protocols

14. WSN Routing Protocols
Routing protocols in WSN
 It play a major role in managing the network , since the different data
forwarding mechanisms lead to different amount and different distribution of
energy consumption in WSN. So, the good choice of routing protocol for
the certain types of deployment under particular radio features plays the
main role in saving the nodes power , thus maximize of the WSN
lifespan
 The routing protocol in WSN has extra tasks in addition to its ordinary
tasks to provide shortest path between source and destination , as shown
below :
1. minimizing energy consumed per packet .
2. maximize time to network partition .
3. minimizing variance in node power levels .
4. minimizing maximum node cost .
so , it are considered the substantial responsible about the network lifespan .
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15. WSN Routing Protocols
WSN Routing Strategies
 At present , array of routing protocols for WSNs are existent, which use
different strategies to address one or more of the restrictions and the
most commonly utilized strategies are :
1. Flooding strategy: it means that every node which receives new
information will forward it to all its neighbors until it reaches its
destination ,such as: Temporally-Ordered Routing Algorithm(TORA).
2. Interest advertisement-request strategy: In this routing protocol
strategy the information is described by meta-data which initially is
exchanged between the nodes. Nodes which acquired new data
advertise it via its meta-data classification. Neighboring nodes which
have an interest in that kind of data reply with a request, achieves
a high energy efficiency compared to flooding strategy, such as:
Sensor Protocols for Information via Negotiation(SPIN).
3. Spatial Location Strategy: A third strategy routing found in WSN
routing protocols uses the knowledge about the spatial position of
sensor nodes to query the WSN in a localized way. If the
deployment of sensor nodes is known, queries for data can be
directed to the area of interest 15

16. WSN Routing Protocols
WSN Routing Protocol Types
 Routing protocols can be classified by several different ways and
considerations , it mat be classified based on “ how and when they
acquire routes in the network” to :
I. Reactive Protocols, Such as : Ad-hoc On-Demand Distance Vector
(AODV).
II. Proactive Protocols, Such as : Optimized Link State Routing
(OLSR).
Or may be based on the network structure to :
I. Flat-based routing protocols where each node plays the same role
and is typically assigned the same functionality.
II. Hierarchical-based routing protocols(also known as clustering-based
routing protocol) where the nodes have to self-organize themselves
into several local clusters, each of which has one node serving as
the cluster-head. A cluster-head collects all the messages in that
cluster and then forwards an aggregate message to a remote base
station (BS). the Low Energy Adaptive Clustering Hierarchy
protocol (LEACH) is considered one of the most common protocol
in this categorize . 16

17. 17
Energy- Efficient Routing Protocol
Algorithms

18. Energy- Efficient Routing Protocol Algorithms
2. Location based routing protocols
It needs some location information of the sensor nodes. Location
information can be obtained from GPS (Global Positioning System)
signals, received radio signal strength, etc. Using location information,
an optimal path can be formed without using flooding techniques.
3. Hierarchical routing protocols
It is used to perform energy efficient routing, i.e., higher energy nodes
can be used to process and send the information; low energy nodes
are used to perform the sensing in the area of interest. e.g. LEACH,
TEEN, APTEEN.
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Energy-
efficient
routing
protocol
algorithms
Data centric Location
based
Hierarchical
1. Data centric protocols
it are query based and they
depend on the naming of the
desired data.
 Energy efficient routing algorithm can be categorized as show in the
diagram below :

19. Energy- Efficient Routing Protocol Algorithms
In this presentation we will address to two types of these algorithms
1. LEACH (Low Energy Adaptive Clustering Hierarchy)
It is hierarchical clustering algorithm which arranges the nodes in the
network into small clusters and chooses one of them as the cluster-head.
Node first senses its target and then sends the relevant information to its
cluster-head. Then the cluster head aggregates and compresses the
information received from all the nodes and sends it to the base station.
Because The nodes chosen as the cluster head drain out more energy as
compared to the other nodes as it is required to send data to the base
station which may be far located.
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So, LEACH uses random rotation of the
nodes required to be the cluster-heads
to evenly distribute energy consumption
in the network
Its operations can be divided into two
phases:-
i. Setup phase .
ii. Steady phase .

20. 20
LEACH ‘s phases algorithms
Steady phaseSet up phase
Energy- Efficient Routing Protocol Algorithms

21. Energy- Efficient Routing Protocol Algorithms
 DECSA (Distance-Energy Cluster Structure Algorithm)
It is hierarchical routing algorithm based on the same concepts of the
classic clustering routing algorithm LEACH and it is considered an improved
version of LEACH. The WSN structure under this algorithm is divided in
three hierarchal level , which divides the nodes into four categories: Base
Station(BS) , Base Station Cluster head(BCH), ordinary cluster head
node (CH), and common sensor node (SN). As shown in figure below
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The DECSA algorithm is a distributed
competitive unequal clustering algorithm,
it considers both the distance and
residual energy information of nodes.
Its operations can be divided into two
stages :-
i. Initialization stage.
ii. Stable working stage
And to minimize energy consumption,the
stable working stage should be greatly
longer than the initialization stage.

22. So if we compare the “LEACH” with “DECSA”
We will realize that “LEACH” :
1. It does not consider the location of sensor nodes, and the selection of cluster
head nodes is random, causing the uneven distribution of cluster head nodes
That is, the cluster-heads can concentrate a specific area within the network.
2. It cannot guarantee a good cluster-head distribution .
3. It is not good for unbalanced-energy network and it leads to the early death
of some nodes in this network because it does not consider the residual
energy of nodes where its algorithm supposes the initial energy of all nodes
are same, and the energy consumption of becoming cluster head node are
basically the same in the first cluster head election.
while the “DECSA”
1. It improves the process of cluster head selecting and the process of cluster
forming.
2. It reduces the adverse effect on the energy consumption of the cluster head,
resulting from the non-uniform distribution of nodes in network
3. It avoided the direct communication between the Base Sensor and cluster
head, which has low energy and far away from Base Sensor.
thus it effectively balances the energy consumption and prolongs of the WSN
lifetime . 22
Energy- Efficient Routing Protocol Algorithms

23. we addressed the WSN lifetime and we realized that the lifespan of WSN is
affected by many reasons such as nodes deployment manner , the energy
of transceiver and the amount of overheads signals which are forwarded
via network , and we realized the "Energy Hole" problem and we
comprehend the solutions of it . and infer that the different data forwarding
mechanisms lead to different amount of and different distribution of energy
consumption , thus the good choice of routing protocol for the certain types
of deployment under particular radio features plays the main role in saving
the nodes power , thus maximize of the WSN lifespan and this make the
routing protocol is the major engine of the saving energy in the WSN . then
we addressed the WSN routing protocol types and understand its
mechanisms and its influences on the WSN lifetime , then study the
LEACH and DECSA efficient-energy clustering routing algorithms and we
concluded the DECSA has a better performance than the original LEACH
protocol.
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Conclusion

24. At the end , I want to thank
Associated Prof. Dr. Ali Gökhan Yavuz
for your help and support
And say
“ thank you to all attendees “
Teşekkür Ederim
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