Cluster-based Routing Protocols for Energy Efficiency in Wireless Sensor Networks

1. Cran Laboratory, Nancy University, CNRS France
CLUSTER-BASED ROUTING PROTOCOLS FOR ENERGY
EFFICIENCY IN WIRELESS SENSOR NETWORKS
Moufida Maimour, Houda Zeghilet And Francis Lepage
Presented By
Santosh Regmi
Mtech In Information
Technology

2. Table Of Content
1)Background
2) Pre-established cluster-based routing algorithms
2.1 Low energy adaptive clustering hierarchy (LEACH)
2.2 Energy efficient hierarchical clustering(EEHC)
2.3 Hybrid energy-efficient distributed clustering(HEED)
2.4 Distributed energy efficient hierarchical
clustering(DWEHC)
2.5 Unequal clustering
2.6 Qos-aware cluster-based routing protocols
3) On-demand cluster-based routing algorithms
3.1 Passive clustering(pc)
3.2 Energy level-based passive clustering(ELPC)
3.3 Clique
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3. Cluster Based Topology
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Type of
communication:
a) Intra-clustering
communication
b) Inter clustering
communication

4. Intra – Cluster Connectivity
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5. One-hop Inter Cluster Communication
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6. Multi-hop Inter-cluster Communication
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7. Energy Efficiency And Load-balancing
• Load balancing among all nodes:
• Cluster head rotation among nodes in each cluster.
• Load balancing among cluster heads:
• Formation of nearly equal size (uniform) clusters.
• Hot spot problem:
• Condition in multi-hop inter-cluster communication,
nodes close to the base station are burdened with heavier
traffic load leading. 11/20/2014 7

8. 2. Pre-Established Cluster-based Routing
Algorithms:
2.1 Low Energy Adaptive Clustering Hierarchy (LEACH):
- cluster-based protocol with distributed cluster formation with random
cluster head election.
• Two phases per round:
• Setup phase
• Advertisement: execute election algorithm.
• Members join to cluster.
• Cluster-head broadcasts schedule.
• Steady-state phase:
• Data transmission to cluster-head using TDMA
• Cluster-head transfers data to BS (base station)
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9. 9
LEACH(CONTD...)
where p is the desired fraction of nodes
to be clusterheads, r is the current
round and g is the set of nodes that
have not been clusterheads in the last
1/p round.
9
Thresshold
Value
Setup phase Steady-state phase
Time slot
1
Time slot
2
Time slot
3
Advertisement phase Cluster setup phase Broadcast schedule
Self-election of cluster
heads
Cluster heads compete
with CSMA
Members
compete with
CSMA
Cluster head Broadcast
CDMA code to members
Fixed-length cycle

10. LEACH-C
• a centralized version of LEACH where only the advertisement
phase differs:
• At this phase, each node sends information about its current
location, and residual energy level to the sink.
• Based on nodes location, the sink builds clusters.
• Collected information about nodes energies allows the sink to
discard those with energy below the average.
• Result:
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• Energy load is evenly distributed among all the nodes.

11. 2.2 ENERGY EFFICIENT HIERARCHICAL CLUSTERING
(EEHC)
a) Single-level clustering algorithm:
• Each sensor in the network becomes a cluster-head (CH) with
probability p, advertises to the sensors within its radio range and
forward advertisement no more than k hops away from the
cluster-head.
• Any sensor that receives such advertisements and is not itself a
cluster-head joins the cluster of the closest cluster-head.
• If a sensor does not receive a CH advertisement within time
duration t ,it can infer that it is not within k hops of any volunteer
cluster-head and hence become a forced cluster-head.
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12. Contd…
B) Hierarchical clustering algorithm
Similar to single-level clustering
algorithm
• Each sensor decides to become a
level-1 CH with certain probability
p1
• Advertise to k1-hop of neighbors
• Neighbor joins the cluster of the
closest level-1 CH.
• Level-1 chs then elect themselves
as level-2 chs with a certain
probability p2
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13. 2.3 HYBRID ENERGY-EFFICIENT DISTRIBUTED
CLUSTERING (HEED)
• Designed to select different cluster heads in
a field according to the amount of energy
that is distributed in relation to a
neighboring node.
• Parameters for electing cluster heads
• Primary parameter: residual energy (er)
• Secondary parameter: communication
cost (used to break ties)
I.E., Maximize energy and minimize cost 11/20/2014 13

14. CONTD…
Initialization Discover neighbors within cluster range
Compute the initial cluster head probability CHprob =
f(Er/Emax)
Main processing If v received some cluster head messages, choose one
head with min cost
If v does not have a cluster head, elect to become a
cluster head with CHprob .
CHprob = min(CHprob * 2, 1)
Repeat until CHprob reaches 1
Finalization If cluster head is found, join its cluster
Otherwise, elect to be cluster head
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15. CLUSTERING METHOD FOR ENERGY EFFICIENT
ROUTING (CMEER)
• A node declares itself as a candidate to be a clusterhead.
• Each candidate advertises its intention to be a clusterhead within
its radio range.
• Each node decides to join a given clusterhead based on the
received signal strength of the advertisement message.
• Result:
• Avoid redundant creation of clusterheads in a small area. 11/20/2014 15

16. 2.4 DISTRIBUTED ENERGY EFFICIENT
HIERARCHICAL CLUSTERING (DWEHC)
• Aims to improve HEED by generating balanced cluster sizes and
optimizing the intra-cluster topology.
• Each sensor s calculates its weight after locating the neighboring
nodes in its area using:
• In a neighbourhood, the node with largest weight would be elected
as a clusterhead and the remaining nodes become members.
• 1- level: nodes that communicates directly with clusterhead
• H-level: member node that reach its clusterhead using more than
one hope where h is number of hops
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17. GEOGRAPHIC ADAPTIVE FIDELITY (GAF)
• Energy-aware location-based routing algorithm
• Ad hoc networks, GPS
• 3 states of GAF:
i. Discovery:
- For determining the neighbors in
the grid.
ii. Active:
- Active reflecting participation in
routing
iii. Sleep:
- When the radio is turned off.
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18. POSITION-BASED AGGREGATOR NODE
ELECTION (PANEL)
• Position-based clustering algorithm.
• Clustering is determined before the deployment of the network,
and each sensor node is pre-loaded with the geographical
information of the cluster to which it belongs.
• Clusterhead (aggregator) : nodes in the cluster elect the node that
is the closest to reference point (computed at the beginning of
every epoch).
• Load balancing is achieved by re-computing reference point at
every epoch and hence electing cluster head 11/20/2014 18

19. 3.5 UNEQUAL CLUSTERING
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• Closer to the sink greater the
load to handle.
• Smaller cluster near the base
station.
• Signomial optimization problem:
• Problem of balancing energy
consumption among cluster
head.

20. 3.6 QOS-AWARE CLUSTER-BASED ROUTING
PROTOCOLS
• Qos is the performance level of service offered by a network to the
user.
• The goal of qos is to achieve a more deterministic network
behavior so that the information carried by the network can be
better delivered and the resources can be better utilized.
• In qos-based routing protocols, the network has to balance
between energy consumption and data quality.
• In particular, the network has to satisfy certain qos metrics, e.G.,
Delay, energy, bandwidth, etc. When delivering data to th11/e20 /2B01S4. 20

21. 3. ON-DEMAND CLUSTER-BASED ROUTING
ALGORITHMS
3.1 PASSIVE CLUSTERING (PC)
• Known as on demand clustering algorithm.
• Cluster formation mechanisms:
i) first declaration wins:
- A node that first claims to be a clusterhead rules the rest of
nodes in its clustered area.
ii) gateway selection heuristic:
- Provides a procedure to elect the minimal number of
gateways.
fields in message header of each packet are:
i) id: identity of the originator of this message.
ii) state: sender status in the network.
iii) ch1 and ch2:fields only used by a gateway to announce its two
clusterhead addresses.
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22. ENERGY LEVEL-BASED PASSIVE CLUSTERING
(ELPC)
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-Proposed to achieve energy efficiency in
terms of network lifetime and energy
consumption.
- NEL:
-Mininum level of energy necessary
for a node to be a clusterhead or a
gateway.
- node is not allowed to declare itself as a
clusterhead ( or a gateway) if its energy
level is lower than this NEL.
- clusterhead can keep its role as long as

23. CONTD…
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24. NETWORK LIFETIME COMPARISION
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25. 4.3 CLIQUE
• An approach for clusterhead selected based on machine learning
(q-learning)
• [Clusterhead role assignment must take into account not only the
current state of the selected clusterheads, but also those of its
neighbors and nodes on the paths to the clusterhead.]
• Role free:
• Each node decides on a per-packet basis whether to act as
clusterhead(aggregating some packets then sending the result
to the sinks) or to forward the packet to a better suited
neighbor. 11/20/2014 25

26. 5. CONCLUSION
• Hierarchical (cluster-based) routing protocols hold a great
potential toward energy efficiency in WSN.
• A global management strategy with load balancing feature is
required.
• Optimal (or even approximate) parameters estimation for
successful clustering is very important
• Network dynamics have to be handled appropriately.
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27. THANK YOU.
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28. REFERENCES
• W. HEINZELMAN, A. CHANDRAKASAN, AND H. BALAKRISHNAN, “ENERGY-EFFICIENT
COMMUNICATION PROTOCOL FOR WIRELESS SENSOR NETWORKS,”
PROCEEDINGS OF THE 33RD HAWAII INTERNATIONAL CONFERENCE ON SYSTEM
SCIENCES, JANUARY 2000.
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