Performance Estimation of a Wireless Sensor Network with a Mobile Sink Moving in Different Trajectories at Different Velocities
Authors: Raina Vikas , Thalore Ranjana , Sharma Jeetu 
Published: December 2019

Background:
Throughout the past few years, numerous Medium Access Control
(MAC) protocols, routing protocols, node deployment mechanisms and duty cycle variation
schemes have been designed for achieving high throughput, low delay and jitter, and long network
lifetime in Wireless Sensor Networks (WSNs). In a WSN with static sink, voluminous sensors
transmit their sensed data to the sink node. The coordinators mutually present in the range of
sensors and sink have to forward a number of packets, which cause rapid depletion of their battery.
These coordinators become dead too early resulting in the breakage of the communication
channel and formation of energy holes. However, to save energy with a static sink, the duty cycle
should be short. A mobile sink is a better option than a static sink if the duty cycle is long, as it
balances energy consumption among the sensors. It is well observed that the mobile sink is capable
of acquiring homogeneous energy depletion leading to stretched lifetime enhancing network
performance.

Methods:
The vital benefaction of this paper is to present a simulation-based analysis of the network
performance with a mobile sink having different trajectories of path traversed at different
velocities. The intent is to find out the most appropriate and efficient trajectory and a particular
velocity for a specific WSN with 100 nodes. The terrain area of the network is 210×210 m2 with
the communication range of 20 m. The routing, network and MAC protocols implemented are Ad
hoc On-Demand Distance Vector (AODV), Internet Protocol version 4 (IPv4) and Institute of
Electrical and Electronics Engineers (IEEE) 802.15.4 respectively. This paper has evaluated and
analyzed the influence of lawn mower, elliptical and circular trajectories of a mobile sink moving
at different velocities of 0.5, 1 and 2 m/s. The optimum performance is achieved at the velocity of
2 m/s for a circular trajectory of the mobile sink. It is observed that performance has significantly
varied with the variation of trajectories and velocities. The notion of precise utilization of sink
mobility improves the performance than a static sink. It is equally important to determine the most
effective mechanism to implement mobile sinks and to find out the most appropriate scheme out
of them.

Results:
The attainment parameters just as total messages received, average end to end delay (seconds),
jitter (seconds), throughput (bits per second), number of packets dropped, number of
packets dropped due to channel access failure, residual battery (mAh) and network lifetime
(hours) for different trajectories such as lawn mower, elliptical and circular at different speeds of
0.5, 1 and 2 m/s of the sink node are evaluated and compared. The simulation results present that
the circular trajectory and the velocity of 2 m/s have provided optimum performance.

Conclusion:
The objective was to precisely analyze and evaluate the influence of different trajectories
of a mobile sink moving at different velocities in a WSN of 100 nodes to determine the
most effective and appropriate trajectory and velocity to optimize the attainments. The intent is to
uniform the power exhaustion amidst the sensors. The purpose was to gain the attention of researchers
of this field to significantly contribute to novel research.