Adaptive Routing Protocols for VANET

A Vehicular Ad-hoc Network (VANET) is a wireless ad-hoc network that
provides communications among vehicles with on-board units and between vehicles
and nearby roadside units. The success of a VANET relies on the ability of a
routing protocol to ful ll the throughput and delivery requirements of any applications
operating on the network. Currently, most of the proposed VANET routing protocols
focus on urban or highway environments. This dissertation addresses the need for an
adaptive routing protocol in VANETs which is able to tolerate low and high-density
network tra c with little throughput and delay variation.
This dissertation proposes three Geographic Ad-hoc On-Demand Distance
Vector (GEOADV) protocols. These three GEOADV routing protocols are designed
to address the lack of
exibility and adaptability in current VANET routing protocols.
The rst protocol, GEOADV, is a hybrid geographic routing protocol. The second
protocol, GEOADV-P, enhances GEOADV by introducing predictive features. The
third protocol, GEOADV-PF improves optimal route selection by utilizing fuzzy logic
in addition to GEOADV-P's predictive capabilities.
To prove that GEOADV and GEOADV-P are adaptive their performance is demonstrated by both urban and highway simulations. When compared to existing
routing protocols, GEOADV and GEOADV-P lead to less average delay and a
higher average delivery ratio in various scenarios. These advantages allow GEOADV-
P to outperform other routing protocols in low-density networks and prove itself
to be an adaptive routing protocol in a VANET environment. GEOADV-PF is
introduced to improve GEOADV and GEOADV-P performance in sparser networks.
The introduction of fuzzy systems can help with the intrinsic demands for
exibility
and adaptability necessary for VANETs.
An investigation into the impact adaptive beaconing has on the GEOADV
protocol is conducted. GEOADV enhanced with an adaptive beacon method is
compared against GEOADV with three xed beacon rates. Our simulation results
show that the adaptive beaconing scheme is able to reduce routing overhead, increase
the average delivery ratio, and decrease the average delay.