SlideShare a Scribd company logo
1
Protocols for Wireless
Sensor Networks
By: Debabrata Singh
Dept. of CSIT,ITER
SOA University, Bhubaneswar
Mail: debabratasingh@soa.ac.in
2
Outline
 Introduction
 Flat Routing Protocols
 Directed Diffusion
 SPIN(Sensor Protocol for Information via Negotiation. )
 Hierarchical Routing Protocols
 LEACH(Low-energy adaptive clustering hierarchy)
 PEGASIS(Power Efficient Gathering in Sensor Information
Systems )
 TEEN(Threshold-sensitive energy efficient sensor network
(TEEN))
 Topic for Discussion
 References
3
Introduction to WSNs
 A sensor network is a computer network of
many, spacially distributed devices using
sensors to monitor conditions at different
locations.
 Involve three areas: sensing,
communications, and computation.
4
Introduction to WSNs
 Sensor nodes scattered in a sensor field
 Each nodes has the capabilities to collect data and route data
back to the sink (Base Station).
 Protocols and algorithms with self-organization capabilities.
5
Introduction - WSNs Topology
 Issues related to topology maintenance and change in
three phases:
 Pre-deployment and deployment phase:
 Sensor nodes can be either thrown in mass or placed one by one in
the sensor field.
 Post-deployment phase:
 Topology changes are due to change nodes' position, reachability,
available energy, malfunctioning, and task details.
 Re-deployment of additional nodes phase:
 Additional sensor nodes can be redeployed at any time to replace
malfunctioning nodes or due to changes in task dynamics.
6
Types of Routing Protocol for WSN
 Single-hop Networks
 The network consists of n nodes, and packets are
transmitted from sources to destinations directly.
 Multi-hop Networks
 The final destination of a packet might not be reached
directly and the other nodes can be used to route the
packet to the final destination.
7
Flat Routing Protocols
 Flat Networks
 Every incoming packet is sent out on every
outgoing line except the one it arrived on.
 Vast numbers of duplicate packets are
generated.
 Routing Protocols: Directed Diffusion, SPIN.
8
The Directed Diffusion Protocol
 Directed Diffusion consists of several
elements:
Interests
Data messages
Gradients
Reinforcements
9
Directed Diffusion - Interest
Propagation
 The sink periodically
broadcasts an interest
message to each of its
neighbors.
 Every node maintains
an interest cache.
10
Directed Diffusion - Gradient
Establishment
 That every pair of
neighboring nodes
establishes a gradient
toward each other.
 This technique can
enable fast recovery
from failed paths or
reinforcement of
empirically better paths.
11
Directed Diffusion - Data
Propagation
 A sensor node that detects a target, it
computes the highest requested event rate
among all its outgoing gradients.
 To resend a received data message, a
node needs to examine the matching
interest entry's gradient list.
12
Directed Diffusion - Reinforcement
 The node might choose
that neighbor from
whom it first received
the latest event
matching the interest to
reinforce.
 It is very reactive to
changes in path quality.
13
The SPIN Protocol
 Sensor Protocols for Information via
Negotiation.
 Start with a source node sending its data
to all of its neighbors.
14
SPIN - Flooding deficiencies
 Implosion & Overlap
(a)
(a)
(a)
A
B C
D
(a)
(r, s)(q, r)
A B
C
q s
r
Implosion Problem Overlap Problem
15
SPIN-1 - three types of messages
 ADV
 When a SPIN node has data to share, it can advertise
an ADV message containing meta-data.
 REQ
 A SPIN node sends an REQ message when it wishes
to receive some actual data.
 DATA
 DATA messages contain actual sensor data with a
meta-data header.
16
ADVREQ
The SPIN-1 Protocol
 Steps
B A
C
D
E
F
DATA
ADV
ADV
ADV
ADVREQ
REQ
DATA
DATA
17
The SPIN-2 Protocol
 When energy is plentiful, SPIN-2 nodes
communicate using the same 3-stage
protocol as SPIN-1 nodes.
 When a SPIN-2 node observes that its
energy is approaching a low-energy
threshold, it adapts by reducing its
participation in the protocol.
18
Hierarchical Routing Protocols
 Hierarchical Networks
The main aim of hierarchical routing is to
efficiently maintain the energy consumption of
sensor nodes.
Performing data aggregation and fusion in
order to decrease the number of transmitted
messages to the sink.
Routing Protocols: LEACH, PEGASIS, TEEN.
19
The LEACH Protocol
 Low-Energy Adaptive Clustering Hierarchy.
 Distributed cluster formation technique
that enables self-organization of large
numbers of nodes.
20
LEACH - Cluster
 Algorithms for adapting clusters and rotating cluster
head positions to evenly distribute the energy load
among all the nodes.
 The nodes organize themselves into local clusters, with
one node acting as the cluster head.
 The cluster head performs signal processing functions
on the data, and transmits data to the remote BS.
21
LEACH - Set-up phase
 Cluster Head
 Each cluster head node broadcasts an advertisement
message (ADV) let all the other nodes that they have
chosen this role for the current round.
 Non-Cluster Head
 They transmits a join-request message (Join-REQ)
back to the chosen cluster head.
22
LEACH - Set-up phase
 The cluster head node sets up a TDMA
schedule and transmits this schedule to the
nodes in the cluster.
 Ensures that there are no collisions among data
messages.
 Allows the radio components to be turned off at
all times except during their transmit time.
23
LEACH - Steady-state phase
 Broken into frames, where nodes send
their data to the cluster head at most once
per frame during their allocated
transmission slot.
 Once the cluster head receives all the data,
it performs data aggregation.
24
LEACH - Time line
 Time line showing LEACH operation
NCH1 NCH2 … … … NCHm-1 NCHm
Slot for NCH2
Frame
ADV Join-REQ SCH
Set-up phase
25
The PEGASIS Protocol
 Power-Efficient GAthering in Sensor
Information Systems.
 The key idea in PEGASIS is to form a
chain among the sensor nodes so that
each node will receive from and
transmit to a close neighbor.
26
PEGASIS - Chain
 The nodes will be organized to form a
chain, which can either be accomplished
by the sensor nodes themselves using a
greedy algorithm starting from some node.
 When a node dies, the chain is
reconstructed in the same manner to
bypass the dead node.
27
PEGASIS - Leader
 The main idea in PEGASIS is for each node to
receive from and transmit to close neighbors
and take turns being the leader for transmission
to the BS.
 Nodes take turns transmitting to the BS, and we
will use node number i mod N (N represents the
number of nodes) to transmit to the BS in round i.
28
PEGASIS - Token
 Token passing approach
N0 N1 N2 N3 N4
BS
Token
Data
29
The TEEN Protocol
 Threshold sensitive Energy Efficient sensor Network
protocol.
 Proactive Protocols (LEACH)
 The nodes in this network periodically switch on their sensors
and transmitters, sense the environment and transmit the data of
interest.
 Reactive Protocols (TEEN)
 The nodes react immediately to sudden and drastic changes in
the value of a sensed attribute.
30
TEEN - Functioning
 At every cluster change time, the cluster-head
broadcasts to its members
 Hard Threshold (HT)
 This is a threshold value for the sensed attribute.
 It is the absolute value of the attribute beyond which, the
node sensing this value must switch on its transmitter and
report to its cluster head.
 Soft Threshold (ST)
 This is a small change in the value of the sensed attribute
which triggers the node to switch on its transmitter and
transmit.
31
TEEN - Hard Threshold
 The first time a parameter from the
attribute set reaches its hard threshold
value, the node switches on its transmitter
and sends the sensed data.
 The sensed value is stored in an internal
variable in the node, called the sensed
value (SV).
32
TEEN - Soft Threshold
 The nodes will next transmit data in the
current cluster period, only when both the
following conditions are true:
The current value of the sensed attribute is
greater than the hard threshold.
The current value of the sensed attribute
differs from SV by an amount equal to or
greater than the soft threshold.
33
TEEN - Drawback
 If the thresholds are not reached, the user
will not get any data from the network at all
and will not come to know even if all the
nodes die.
 This scheme practical implementation
would have to ensure that there are no
collisions in the cluster.
34
References
 I.F. Akyildiz, W. Su*, Y. Sankarasubramaniam, and E. Cayirci,
 "Wireless sensor networks: a survey".
 K. Akkaya, M. Younis,
 "A Survey on Routing Protocols for Wireless Sensor Networks".
 J.N. Al-Karaki, A.E. Kamal,
 "Routing Techniques in Wireless Sensor Networks".
 C. Intanagonwiwat, R. Govindan, and D. Estrin,
 "Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networks".
 W. Heinzelman, J. Kulik, and H. Balakrishnan,
 "Adaptive Protocols for Information Dissemination in Wireless Sensor Networks".
 W. Heinzelman, A. Chandrakasan, and H. Balakrishnan,
 "An Application-Specific Protocol Architecture for Wireless Microsensor Networks".
 S. Lindsey and C. Raghavendra,
 "PEGASIS: Power-Efficient Gathering in Sensor Information Systems".
 A. Manjeshwar and D. Agrawal,
 "TEEN: A Routing Protocol for Enhanced Efficiency in Wireless Sensor Networks".

More Related Content

Protocols for wireless sensor networks

  • 1. 1 Protocols for Wireless Sensor Networks By: Debabrata Singh Dept. of CSIT,ITER SOA University, Bhubaneswar Mail: debabratasingh@soa.ac.in
  • 2. 2 Outline  Introduction  Flat Routing Protocols  Directed Diffusion  SPIN(Sensor Protocol for Information via Negotiation. )  Hierarchical Routing Protocols  LEACH(Low-energy adaptive clustering hierarchy)  PEGASIS(Power Efficient Gathering in Sensor Information Systems )  TEEN(Threshold-sensitive energy efficient sensor network (TEEN))  Topic for Discussion  References
  • 3. 3 Introduction to WSNs  A sensor network is a computer network of many, spacially distributed devices using sensors to monitor conditions at different locations.  Involve three areas: sensing, communications, and computation.
  • 4. 4 Introduction to WSNs  Sensor nodes scattered in a sensor field  Each nodes has the capabilities to collect data and route data back to the sink (Base Station).  Protocols and algorithms with self-organization capabilities.
  • 5. 5 Introduction - WSNs Topology  Issues related to topology maintenance and change in three phases:  Pre-deployment and deployment phase:  Sensor nodes can be either thrown in mass or placed one by one in the sensor field.  Post-deployment phase:  Topology changes are due to change nodes' position, reachability, available energy, malfunctioning, and task details.  Re-deployment of additional nodes phase:  Additional sensor nodes can be redeployed at any time to replace malfunctioning nodes or due to changes in task dynamics.
  • 6. 6 Types of Routing Protocol for WSN  Single-hop Networks  The network consists of n nodes, and packets are transmitted from sources to destinations directly.  Multi-hop Networks  The final destination of a packet might not be reached directly and the other nodes can be used to route the packet to the final destination.
  • 7. 7 Flat Routing Protocols  Flat Networks  Every incoming packet is sent out on every outgoing line except the one it arrived on.  Vast numbers of duplicate packets are generated.  Routing Protocols: Directed Diffusion, SPIN.
  • 8. 8 The Directed Diffusion Protocol  Directed Diffusion consists of several elements: Interests Data messages Gradients Reinforcements
  • 9. 9 Directed Diffusion - Interest Propagation  The sink periodically broadcasts an interest message to each of its neighbors.  Every node maintains an interest cache.
  • 10. 10 Directed Diffusion - Gradient Establishment  That every pair of neighboring nodes establishes a gradient toward each other.  This technique can enable fast recovery from failed paths or reinforcement of empirically better paths.
  • 11. 11 Directed Diffusion - Data Propagation  A sensor node that detects a target, it computes the highest requested event rate among all its outgoing gradients.  To resend a received data message, a node needs to examine the matching interest entry's gradient list.
  • 12. 12 Directed Diffusion - Reinforcement  The node might choose that neighbor from whom it first received the latest event matching the interest to reinforce.  It is very reactive to changes in path quality.
  • 13. 13 The SPIN Protocol  Sensor Protocols for Information via Negotiation.  Start with a source node sending its data to all of its neighbors.
  • 14. 14 SPIN - Flooding deficiencies  Implosion & Overlap (a) (a) (a) A B C D (a) (r, s)(q, r) A B C q s r Implosion Problem Overlap Problem
  • 15. 15 SPIN-1 - three types of messages  ADV  When a SPIN node has data to share, it can advertise an ADV message containing meta-data.  REQ  A SPIN node sends an REQ message when it wishes to receive some actual data.  DATA  DATA messages contain actual sensor data with a meta-data header.
  • 16. 16 ADVREQ The SPIN-1 Protocol  Steps B A C D E F DATA ADV ADV ADV ADVREQ REQ DATA DATA
  • 17. 17 The SPIN-2 Protocol  When energy is plentiful, SPIN-2 nodes communicate using the same 3-stage protocol as SPIN-1 nodes.  When a SPIN-2 node observes that its energy is approaching a low-energy threshold, it adapts by reducing its participation in the protocol.
  • 18. 18 Hierarchical Routing Protocols  Hierarchical Networks The main aim of hierarchical routing is to efficiently maintain the energy consumption of sensor nodes. Performing data aggregation and fusion in order to decrease the number of transmitted messages to the sink. Routing Protocols: LEACH, PEGASIS, TEEN.
  • 19. 19 The LEACH Protocol  Low-Energy Adaptive Clustering Hierarchy.  Distributed cluster formation technique that enables self-organization of large numbers of nodes.
  • 20. 20 LEACH - Cluster  Algorithms for adapting clusters and rotating cluster head positions to evenly distribute the energy load among all the nodes.  The nodes organize themselves into local clusters, with one node acting as the cluster head.  The cluster head performs signal processing functions on the data, and transmits data to the remote BS.
  • 21. 21 LEACH - Set-up phase  Cluster Head  Each cluster head node broadcasts an advertisement message (ADV) let all the other nodes that they have chosen this role for the current round.  Non-Cluster Head  They transmits a join-request message (Join-REQ) back to the chosen cluster head.
  • 22. 22 LEACH - Set-up phase  The cluster head node sets up a TDMA schedule and transmits this schedule to the nodes in the cluster.  Ensures that there are no collisions among data messages.  Allows the radio components to be turned off at all times except during their transmit time.
  • 23. 23 LEACH - Steady-state phase  Broken into frames, where nodes send their data to the cluster head at most once per frame during their allocated transmission slot.  Once the cluster head receives all the data, it performs data aggregation.
  • 24. 24 LEACH - Time line  Time line showing LEACH operation NCH1 NCH2 … … … NCHm-1 NCHm Slot for NCH2 Frame ADV Join-REQ SCH Set-up phase
  • 25. 25 The PEGASIS Protocol  Power-Efficient GAthering in Sensor Information Systems.  The key idea in PEGASIS is to form a chain among the sensor nodes so that each node will receive from and transmit to a close neighbor.
  • 26. 26 PEGASIS - Chain  The nodes will be organized to form a chain, which can either be accomplished by the sensor nodes themselves using a greedy algorithm starting from some node.  When a node dies, the chain is reconstructed in the same manner to bypass the dead node.
  • 27. 27 PEGASIS - Leader  The main idea in PEGASIS is for each node to receive from and transmit to close neighbors and take turns being the leader for transmission to the BS.  Nodes take turns transmitting to the BS, and we will use node number i mod N (N represents the number of nodes) to transmit to the BS in round i.
  • 28. 28 PEGASIS - Token  Token passing approach N0 N1 N2 N3 N4 BS Token Data
  • 29. 29 The TEEN Protocol  Threshold sensitive Energy Efficient sensor Network protocol.  Proactive Protocols (LEACH)  The nodes in this network periodically switch on their sensors and transmitters, sense the environment and transmit the data of interest.  Reactive Protocols (TEEN)  The nodes react immediately to sudden and drastic changes in the value of a sensed attribute.
  • 30. 30 TEEN - Functioning  At every cluster change time, the cluster-head broadcasts to its members  Hard Threshold (HT)  This is a threshold value for the sensed attribute.  It is the absolute value of the attribute beyond which, the node sensing this value must switch on its transmitter and report to its cluster head.  Soft Threshold (ST)  This is a small change in the value of the sensed attribute which triggers the node to switch on its transmitter and transmit.
  • 31. 31 TEEN - Hard Threshold  The first time a parameter from the attribute set reaches its hard threshold value, the node switches on its transmitter and sends the sensed data.  The sensed value is stored in an internal variable in the node, called the sensed value (SV).
  • 32. 32 TEEN - Soft Threshold  The nodes will next transmit data in the current cluster period, only when both the following conditions are true: The current value of the sensed attribute is greater than the hard threshold. The current value of the sensed attribute differs from SV by an amount equal to or greater than the soft threshold.
  • 33. 33 TEEN - Drawback  If the thresholds are not reached, the user will not get any data from the network at all and will not come to know even if all the nodes die.  This scheme practical implementation would have to ensure that there are no collisions in the cluster.
  • 34. 34 References  I.F. Akyildiz, W. Su*, Y. Sankarasubramaniam, and E. Cayirci,  "Wireless sensor networks: a survey".  K. Akkaya, M. Younis,  "A Survey on Routing Protocols for Wireless Sensor Networks".  J.N. Al-Karaki, A.E. Kamal,  "Routing Techniques in Wireless Sensor Networks".  C. Intanagonwiwat, R. Govindan, and D. Estrin,  "Directed Diffusion: A Scalable and Robust Communication Paradigm for Sensor Networks".  W. Heinzelman, J. Kulik, and H. Balakrishnan,  "Adaptive Protocols for Information Dissemination in Wireless Sensor Networks".  W. Heinzelman, A. Chandrakasan, and H. Balakrishnan,  "An Application-Specific Protocol Architecture for Wireless Microsensor Networks".  S. Lindsey and C. Raghavendra,  "PEGASIS: Power-Efficient Gathering in Sensor Information Systems".  A. Manjeshwar and D. Agrawal,  "TEEN: A Routing Protocol for Enhanced Efficiency in Wireless Sensor Networks".