Vehicular Ad hoc Networks (VANET) is a wireless ad-hoc network that includes
two types of communications, Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure
(V2I). In VANET there are two types of messages. The first type is the event-driven
messages that are only triggered in case of emergency. The second type is the periodical
messages named beacons that are exchanged frequently between vehicles. A
beacon message contains basic information about the sending vehicle such as id, location
and velocity. Beacons are frequently exchanged to increase the cooperative
awareness between vehicles. Increasing beacon frequency helps increasing neighborhood
awareness and improving information accuracy. However, this causes more
congestion in the network, specially when the number of vehicles increases. On the
other hand, reducing beacon frequency alleviates network congestion, but results in
out-dated information.
In this dissertation, we address the aforementioned challenges and propose a
number of smart beaconing protocols and evaluate their performance in di↵erent environments
and network densities. The four adaptive beaconing protocols are designed
to increase the cooperative awareness and information freshness, while alleviating the network congestion. All the proposed protocols take into account the most important
aspects, which are critical to beaconing rate adaptation. These aspects include channel
status, traffic conditions and link quality. The proposed protocols employ fuzzy
logic-based techniques to determine the congestion rank, which is used to adjust beacon
frequency.
The first protocol considers signal to interference-noise ratio (SINR), number
of neighboring nodes and mobility to determine the congestion rank and adjust the
beacon rate accordingly. This protocol works well in sparse conditions and highway
environments. The second protocol works well in sparse conditions and urban environments.
It uses channel busy time (CBT), mobility and packet delivery ratio
(PDR) to determine the congestion rank and adjust the beacon rate. The third protocol
utilizes CBT, SINR, PDR, number of neighbors and mobility as inputs for the
fuzzy logic system to determine the congestion rank and adjust the beacon rate. This
protocol works well in dense conditions in both highway and urban environments.
Through extensive simulation experiments, we established that certain input
parameters are more e↵ective in beacon rate adaptation for certain environments
and conditions. Based on this, we propose a high awareness and channel efficient
scheme that adapts to di↵erent environments and conditions. First, the protocol
estimates the network density using adaptive threshold function. Then, it looks at
the spatial distribution of nodes using the quadrat method to determine whether
the environment is highway or urban. Based on the density conditions and nodes
distribution, the protocol utilizes the appropriate fuzzy input parameters to adapt
the beaconing rate. In addition, the protocol optimizes the performance by adapting
the transmission power based on network density and nodes distribution.
Finally, an investigation of the impact of adaptive beaconing on broadcasting
is conducted. The simulation results confirm that our adaptive beaconing scheme
can improve performance of the broadcast protocols in terms of reachability and bandwidth consumption when compared to a fixed rate scheme. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
| Identifer | oai:union.ndltd.org:fau.edu/oai:fau.digital.flvc.org:fau_40903 |
| Contributors | Alhameed, Mohammed (author), Mahgoub, Imad (Thesis advisor), Florida Atlantic University (Degree grantor), College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science |
| Publisher | Florida Atlantic University |
| Source Sets | Florida Atlantic University |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation, Text |
| Format | 148 p., application/pdf |
| Rights | Copyright © is held by the author with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder., http://rightsstatements.org/vocab/InC/1.0/ |
Page generated in 0.0013 seconds