This document summarizes a student project that evaluates the Stable Election Protocol (SEP) for wireless sensor networks and proposes a modification to improve network lifetime. SEP is designed for heterogeneous networks and aims to prolong stability period by assigning higher election probabilities to nodes with more energy. The project seeks to further increase stability period by tweaking SEP to only allow higher energy nodes within a set distance of cluster heads to communicate. Simulation results show the modified SEP outperforms the base SEP in terms of total energy consumption, data received by the base station, number of alive nodes over time, and overall stability period.

1. PERFORMANCE EVALUATION &
BENEFITS OF STABLE ELECTION
PROTOCOL IN WSNs
Vamika Shrivastava
9911103590
F2, CSE

2. WSNs
• A WSN is made up of multiple stations meant for
detection, called sensor nodes.
• Every sensor node is made up of mechanical parts
known as a transducer, a microcomputer, a
transceiver and a source of power.
• The most important aspect of WSN applications is
its lifetime which is primarily constrained and
limited by the amount of energy consumed by the
sensors, which are driven by unrechargeable
batteries also hard to replace due to deployment
in hostile environments.

3. • Once the nodes begin to exhaust their energies
(become dead), the tolerance of the network goes
on decreasing, until such a time when it can no
longer be operational.
• The period of time from the beginning of network
operation till the first node dies may be referred to
as the stability period

4. Aim of Project
• An endeavour to study a protocol that may
increase this stability period of a WSN as one of
the aims of increasing the efficiency and lifetime of
the network to improve WSN’s commercial
viability.
• The project will study the effect of a protocol
named Stable Election Protocol (SEP) and try to
make some small, innovative changes to improve
this stability period.

5. SEP
• SEP is a WSN protocol that assumes heterogeneity
in a network, making it the basis to prolong the
stability period in a hierarchically clustered.
• For Heterogeneous networks, it is assumed that
each node has different energy, one of the various
levels defined (two tiered/ three tiered/ n- tiered.

6. How SEP works
• Nodes are treated differently based on their initial
energy levels.
• The nodes with lower energy are called normal
nodes and assigned a weighted election
probability Pnrm which is lower to Padv which is the
weighted election probability assigned to the
advanced nodes, i.e., the nodes with higher energy
levels.

7. •This ensures that higher energy nodes have higher
probability of being elected CH, thus ensuring that
the energy within the network is consumed in a
balanced manner thus prolonging the stability
period.

9. Innovative Modification
• This particular project seeks to introduce another
dimension of novelty in this novel approach to
maximisation of network lifetime – that is it
tweaks the known SEP to allow only higher energy
nodes in a cluster to operate.
• This is done by selecting only those nodes for
communication with CH in a cluster whose
distance with the CH is equal to the minimum
distance calculated in each round at the selection
of a CH.

10. • The parameter of distance is selected because
maximum energy consumption in a sensor node
occurs in transmission of data, which is what will
primarily determine the remaining energy and
energy level of a sensor node.

11. Results

14. Conclusion
• From the above graphs it is clearly visible that in
the simulations run for this project, the Modified
SEP is much better than Base SEP, with regard to
all important performance parameters, such as
Total Energy Consumption, Total Data received by
BS, Number of Alive Nodes at simulation end, and
the main focus of the project as well as Stability
Period.

15. • SEP not only prolongs Stability Period as
compared to LEACH as proved in existing work,
but also the Modified SEP algorithm proposed in
this project improves upon the performance of
Base SEP as well, also performing better on other
parameters.

16. Thank You!