Unraveling Multimodality with Large Language Models.pdf
Leach protocol
1. LEACH protocol for
WIRELESS SENSOR NETWORK
CALCUTTA INSTITUTE OF ENGINEERING AND MANAGEMENT
24/1A, CHANDI GHOSH ROAD, KOLKATA-700040
2012-2013
Presented by: RAMESH VERMA
ANIL KUMAR
PRAVIND KUMAR
C.S.E.4th Year
2. Overview-LowEnergyAdaptiveClusteringHierarchy
(LEACH)
Introduction to leach protocol
Two phases of leach
Set-up phase/ thresold algorithm
Set-up phase/advertisement
Set-up to steady state phase
Weakness in leach
DECSA(Distance Energy Cluster Structure Algorithm )
Initialization stage
Stable working stage
comparision
3. IntroductiontoLEACHprotocol
Falls under hierarchical networks
Self-organizing, adaptive clustering protocol that
uses randomization to distribute energy load evenly
Dense network of sensor nodes grouped into
clusters.
All nodes are assumed to be homogenous + energy
constrained.
Base station is fixed + away from sensors.
Cluster member elect cluster head to avoid excessive
energy consumption.
Incorporates data aggregation.
4. LEACH two phases
It has two phases
The set-up phase and the steady- state phase
The set-up phase where cluster heads are chosen
The steady state phase the cluster head is maintained
where data is transmitted between nodes
5. Set-up phase/ Thresold
algorithm
Cluster-heads can be chosen stochastically
(randomly based) on this algorithm:
T(n) =P/1-P*(r mod/p) if n€G
0 , otherwise
Where n is a random no. between 0 and 1 and
P is cluster head probability and G is the set of
nodes that were not cluster head in the last round.
If n <T(n), then that node becomes a cluster
head
The algorithm is designed so that each node
becomes a cluster-head at least once
6. Algorithm - Setup Phase |
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Each node that elected itself a cluster-head for
current round broadcasts advertisement
message to rest of nodes
All cluster-heads transmit advertisement using
same transmit energy
Non-cluster-head nodes must keep receivers on
during this phase to hear advertisements
now they decide which cluster to belong to for
this round by choosing cluster-head that requires
minimum communication energy
In case of ties, random cluster-head chosen
7. Algorithm - Setup to Steady
Phase
After node picks cluster, must inform cluster-
head
Cluster-head now knows number of members
cluster-head then creates a TDMA schedule
telling each node when it can transmit
allows radio components of each non-cluster-
head node to be turned off during its transmit
time, thus minimizing energy dissipated in
individual sensors
cluster-head now has all data from the nodes in
its cluster, aggregates data & transmits to base
8. Weakness in LEACH
LEACH assumes that
all nodes can communicate with each other and are able to
reach the sink (therefore, it is only suitable for small size
networks)
all nodes have data to send and so assign a time slot for a
node even though some nodes might not have data to
transmit.
all nearby nodes have correlated data which is not always true
all nodes are continuously listening ( this is not realistic in a
random distribution of the sensor nodes, for example, where
cluster-heads would be located at the edge of the network),
9. DECSA (Distance Energy Cluster
Structure Algorithm)
DECSA is improvement over LEACH.
It considers both the distance and residual energy
information of nodes.
Three level hierarchy structure of DECSA consists of
BS(Base Station), BCH(Base Station Cluster Head), CH(
ordinary Cluster head), SN(sensor nodes)
10. Initialization Stage
The process of cluster head select consists of following 2
parts: election of ordinary cluster head node (CH) and election
of Base Station Cluster head (BCH)
First round cluster head is called false-cluster-head
All nodes compare their k(i) with the false cluster head.
If k(i) < false cluster head’s k(i), then false cluster head
becomes CH otherwise the node.
k(i)=En(i)/do(i)
k(i)=thresold of elected CH
En(i)=residual energy of node i
do(i)=average distance of node I from all other nodes in the
network
11. Initialization Stage
Selection of BCH
1.TBCH of all CH is calculated and compared
with predefinedTBCH0
2. CH whoseTBCH are larger than the predefined
thresholdTBCH0 becomes the base-station cluster-
head( BCH).
TBCH(i)=(En(i)/Eo)+(En(i)/d(i))
En(i)=current residual energy of node I
Eo is the initial energy of node in the network
d(i)= distance between node I and the base station
12. Stable working Stage
base station broadcasts the message to the entire
network forming a communication path.
Common nodes (SN) in the cluster will transmit data
packet to their closest cluster-head
luster-head will collect and fusion those data and
transmit them to the base-station cluster- head, rather
than transmit them to the base station directly
then, base-station-cluster-head will communicate with
the base station
13. Comparison
DECSA prolongs 31% of the lifetime, reduces 40% of the energy
consumption and has a better performance than the original LEACH
protocol.
. Residual energy relationship of nodes between DECSA and LEACH
14. Conclusion
DECSA considering both the distance and
residual energy of nodes
It improved the process of cluster head
election and the process of data transmission
of network
Reduces the adverse effect on the energy
consumption of the cluster head
prolongs 31% of the lifetime, reduces 40% of
the energy consumption.
15. Bibiliography
“Low Energy Adaptive Clustering Hierarchy with
Deterministic Cluster-Head Selection”; M.J.Handy,
M. Haas, D.Timmermann; 2002;
http://www.vs.inf.ethz.ch/publ/se/IEEE_MWCN2
002.pdf
“Probabilistic Modeling of Leach Protocol and
Computing Sensor Energy Consumption Rate in
Sensor Networks”; Song, Dezhen; February
22,2005;
http://www.cs.tamu.edu/academics/tr/tamu-cstr-
2005-2-2