Thesis (PHD.) - Cyprus International University. Institute of Graduate Studies and Research Computer Engineering Department

Includes bibliography (sheets 102-109)

ABSTRACT
The design and implementation of development methods are addressed using a
framework of information and communication technology that offers guidance to a
smart city in redesigning, implementing, and promoting different development
processes. One of the technologies that allow the development of smart cities is the
Intelligent Transportation System (ITS). One of the technologies that allow the
development of smart cities is the Intelligent Transportation System (ITS). VANETs
(Vehicular Ad-hoc NETworks) play an essential role in ITS. Vehicle-to-vehicle
(V2V), vehicle-to-infrastructure (V2I), and vehicle-to-everything (V2X), broadcasting
is a method used by vehicles and other components in the VANET to share
information. While changing broadcasting techniques has its benefits, it also has its
drawbacks. If several vehicles broadcast the same message, for example, the network
will be flooded with messages, this is known as a broadcast storm, and it occurs when
the network transmission is overloaded. As a result, the number of vehicles
rebroadcasting signals must be reduced. In this research, this issue is addressed by
proposing a new mechanism called as Delay Time aware Controlled Rebroadcasting
(DTCR) mechanism.
The proposed DTCR mechanism makes the vehicle generate Time To Live value while
broadcasting the messages. The TTL value of the messages is generated by considering
parameters like delay time, transmission time as maximum and busy channel ratio. The
recipient vehicle of the messages checks the transmission vehicle's vicinity. If the
receiver is far from the sender, it moves the messages to the buffer and waits for the
delay timer to expire. During this waiting time, if any other message with the same ID
is received, the vehicle marks the message as duplicate and discards the messages. If
none received, the vehicle would rebroadcast the message by decreasing the TTL
value. This process makes the vehicles apply a delay time before rebroadcasting
messages which in turn makes the vehicle receive already rebroadcasted messages.
Thus the vehicles which are receiving the copies of the messages will discard the
message and do not rebroadcast the messages. The proposed DTCR mechanism is
implemented and simulated in Omnet++, SUMO and VEINS simulation tools. Results
of analysis and simulation show that the DTCR improves system performance in terms
of performance, delivery ratios, and delay compared to conventional routing protocols.
In general, the proposed technique showing an improvement of 10% than other
methods in several metrics cumulatively.