Performance evaluation of Vehicular Ad Hoc Networks over high speed environment using NCTUns

Català: Cada any aproximadament un milió dues-centes mil persones moren en accidents de trànsit. D'aquesta dada es desprèn que els accidents de trànsit són la quarta causa de mortalitat al món. Degut a això, un gran nombre de governs i els majors fabricants de vehicles del món estan invertint temps i diners en recerca i desenvolupament per millorar la seguretat a les carreteres. Amb aquest objectiu, apareix el concepte de VANET: Vehicular Ad-hoc NETwork. Una VANET està basada en vehicles i estacions base intel·ligents que comparteixen informació a través de comunicacions inalàmbriques. Aquest intercanvi de dades podria tenir un gran impacte en la seguretat viària i la qualitat en la conducció però a més a més seria una nova font d' entreteniment mòbil. La millora en seguretat implicaria una reducció en el nombre d'accidents i les comunicacions inalàmbriques usades en mobilitat permetrien una optimització del transport. L'evolució de les VANETs en els últims anys i les seves aplicacions útils a les carreteres són les principals raons per dur a terme aquest projecte. El gran suport a aquest tipus de xarxes inalàmbriques sembla indicar que les VANETs són les xarxes del futur en entorns mòbils. En relació al projecte, el primer problema observat és que el protocol que s'usa específicament en VANETs (802.11p) només està disponible en pocs simuladors de xarxa i està en fase de desenvolupament. Per tant, la majoria de les funcions no estan implementades i això fa que el protocol no sigui madur. En conseqüència, es va triar un protocol àmpliament usat com és 802.11b per fer les proves en el simulador NCTUns. L?objectiu del projecte és avaluar el funcionament de VANETs usant el protocol 802.11b i el protocol d?encaminament AODV en un escenari d?autopista. Ajustant diferents paràmetres com el nombre de cotxes, la seva velocitat i el seu rang de cobertura és possible obtenir variacions en les mesures de pèrdues, throughput i retard extrem-a-extrem en la xarxa. El resultat final és que les mesures permeten saber quines són les comunicacions que es produeixen a la xarxa per cadascuna de les configuracions i la seva incidència en les condicions de conducció.Castellano: Cada año cerca de un millón doscientas mil personas fallecen en accidentes de tráfico. De este dato se desprende que los accidentes de tráfico son la cuarta causa de mortalidad en el mundo. Debido a esto, un gran número de gobiernos y los mayores fabricantes de vehículos del mundo están invirtiendo tiempo y dinero en investigación y desarrollo para mejorar la seguridad en las carreteras. Con este objetivo, aparece el concepto de VANET: Vehicular Ad-hoc NETwork. Una VANET se basa en vehículos y estaciones base inteligentes que comparten información por medio de comunicaciones inalámbricas. Este intercambio de datos podría tener un gran impacto en la seguridad vial y en la calidad de la conducción pero además sería una nueva fuente de entretenimiento móvil. La mejora en la seguridad implicaría una reducción en el número de accidentes y las comunicaciones inalámbricas utilizadas en movilidad permitirían optimizar el transporte. La evolución de las VANETs en los últimos años y sus aplicaciones útiles en las carreteras son las principales razones para llevar a cabo este proyecto. El gran apoyo a este tipo de redes inalámbricas parece indicar que las VANETs son las redes del futuro en entornos móviles. En relación al proyecto, el primer problema observado es que el protocolo específicamente utilizado en VANETs (802.11p) sólo está disponible en pocos simuladores de red y se encuentra en fase de desarrollo. Por lo tanto, la mayoría de funciones no están implementadas y esto hace que el protocolo no sea maduro. En consecuencia, se escogió un protocolo ampliamente utilizado como es 802.11b para realizar las pruebas en el simulador NCTUns. El objetivo del proyecto es evaluar el funcionamiento de VANETs utilizando el protocolo 802.11b y el protocolo de encaminamiento AODV en un escenario de autopista. Ajustando diferentes parámetros como el número de coches, su velocidad y su rango de cobertura es posible obtener variaciones en las medidas de pérdidas, throughput y retardo extremo-a-extremo en la red. El resultado final es que las medidas permiten saber cuáles son las comunicaciones que se producen en la red para cada una de las configuraciones y su incidencia en las condiciones de conducción.English: Every year about 1.2 million people die because of traffic accidents [1]. This means that traffic accidents are the fourth cause of mortality in the world. Therefore, several governments and the most important car manufacturers are investing time and money on research and development in order to improve road safety. At this respect, appears the concept of VANET: Vehicular Ad-hoc NETwork. A VANET is based on smart cars and base-stations that share information via wireless communications. This interchange of data may have a great impact on safety and driving quality but also could be another source of mobile entertainment. This improvement on safety would imply reducing the number of accidents. In addition, the use of wireless communications in mobility would lead to an optimization of transport. The evolution of VANETs in the last years and their useful applications on the road has been the main reason to develop this project. The great support of many people to this type of wireless networks suggests that VANETs are the networks of the future in mobile environments. Regarding the project, the first problem encountered is that the network protocol specially designed for VANETs, IEEE 802.11p, is only available in a few of the network simulators and is on phase of development. This fact means that most of the functions are not implemented so it cannot be considered as a mature protocol. As a consequence, a widely used protocol as IEEE 802.11b was chosen and all the tests were performed on NCTUns simulator. So the purpose of this project is to evaluate the performance of VANETs by using 802.11b protocol and AODV routing protocol in a highway scenario. By adjusting different parameters like number of cars, their speed and their range of coverage, variations on measures of loss ratio, throughput and end-to- end delay were detected on the network. Finally, the measures help to know about network communications for each of the cases and their incidence on driving conditions

Dissection of Mobility Model Routing Protocols in MANET on QoS Criterion

Essential difficulties in Mobile Ad Hoc Networks (MANET) are routing selection and Quality of Service(QoS) support. Several different approaches have been described in the literature, and a number of performance simulations have been produced, in an attempt to tackle this challenging problem. In this study, we take a close look at the relative merits of several popular routing protocols. In this research, we looked into how changing QoS parameters in tandem with routing protocol choices affected network throughput. Typical measures for measuring network efficiency include average throughput, packet delivery ratio (PDR), average delay, and power usage. NS-3 is used to run the simulations

The dynamic counter-based broadcast for mobile ad hoc networks

Broadcasting is a fundamental operation in mobile ad hoc networks (MANETs) crucial to the successful deployment of MANETs in practice. Simple flooding is the most basic broadcasting technique where each node rebroadcasts any received packet exactly once. Although flooding is ideal for its simplicity and high reachability it has a critical disadvantage in that it tends to generate excessive collision and consumes the medium by unneeded and redundant packets. A number of broadcasting schemes have been proposed in MANETs to alleviate the drawbacks of flooding while maintaining a reasonable level of reachability. These schemes mainly fall into two categories: stochastic and deterministic. While the former employs a simple yet effective probabilistic principle to reduce redundant rebroadcasts the latter typically requires sophisticated control mechanisms to reduce excessive broadcast. The key danger with schemes that aim to reduce redundant broadcasts retransmissions is that they often do so at the expense of a reachability threshold which can be required in many applications. Among the proposed stochastic schemes, is counter-based broadcasting. In this scheme redundant broadcasts are inhibited by criteria related to the number of duplicate packets received. For this scheme to achieve optimal reachability, it requires fairly stable and known nodal distributions. However, in general, a MANETs‟ topology changes continuously and unpredictably over time. Though the counter-based scheme was among the earliest suggestions to reduce the problems associated with broadcasting, there have been few attempts to analyse in depth the performance of such an approach in MANETs. Accordingly, the first part of this research, Chapter 3, sets a baseline study of the counter-based scheme analysing it under various network operating conditions. The second part, Chapter 4, attempts to establish the claim that alleviating existing stochastic counter-based scheme by dynamically setting threshold values according to local neighbourhood density improves overall network efficiency. This is done through the implementation and analysis of the Dynamic Counter-Based (DCB) scheme, developed as part of this work. The study shows a clear benefit of the proposed scheme in terms of average collision rate, saved rebroadcasts and end-to-end delay, while maintaining reachability. The third part of this research, Chapter 5, evaluates dynamic counting and tests its performance in some approximately realistic scenarios. The examples chosen are from the rapidly developing field of Vehicular Ad hoc Networks (VANETs). The schemes are studied under metropolitan settings, involving nodes moving in streets and lanes with speed and direction constraints. Two models are considered and implemented: the first assuming an unobstructed open terrain; the other taking account of buildings and obstacles. While broadcasting is a vital operation in most MANET routing protocols, investigation of stochastic broadcast schemes for MANETs has tended to focus on the broadcast schemes, with little examination on the impact of those schemes in specific applications, such as route discovery in routing protocols. The fourth part of this research, Chapter 6, evaluates the performance of the Ad hoc On-demand Distance Vector (AODV) routing protocol with a route discovery mechanism based on dynamic-counting. AODV was chosen as it is widely accepted by the research community and is standardised by the MANET IETF working group. That said, other routing protocols would be expected to interact in a similar manner. The performance of the AODV routing protocol is analysed under three broadcasting mechanisms, notably AODV with flooding, AODV with counting and AODV with dynamic counting. Results establish that a noticeable advantage, in most considered metrics can be achieved using dynamic counting with AODV compared to simple counting or traditional flooding. In summary, this research analysis the Dynamic Counter-Based scheme under a range of network operating conditions and applications; and demonstrates a clear benefit of the scheme when compared to its predecessors under a wide range of considered conditions

SGIRP: A Secure and Greedy Intersection-Based Routing Protocol for VANET using Guarding Nodes

Vehicular Ad Hoc Network (VANET) is an advance wireless technology in the field of wireless communication to provide better Intelligent Transportation Services (ITS). It is an emerging area of research in the field of vehicular technology for its high mobility and high link disruption. VANET provides better road services to the end users by providing safety to the passengers and drivers. Multimedia sharing, e-shopping, safety systems, etc. are some of ITS services provided by VANET. VANETs are strongly affected by link disruption problem for their high mobility and randomness. Security is also a main issue in VANET nowadays, which degrades the network performance. In this thesis, we present a Secure and Greedy Intersection-Based Routing Protocol (SGIRP) to transmit the data securely from source (S) to the destination (D) in a shortest path. For this, we have set Guarding Nodes (GNs) at every intersection to relay the packet from one intersection to other in a secure manner. GN helps in calculating the updated shortest paths to D, protects the network from malicious attacks by using authentication scheme and also recovers the network from Communication Voids (CV). GN plays an important role in transmitting the data from S to D in a fast and secure way. At last, we evaluate our proposed SGIRP protocol by deriving and proving the lemmas related to the protocol. It is also proved that SGIRP protocol shows better performance than Gytar protocol in terms of shorter time delay (T)

Bandwidth and Energy-Efficient Route Discovery for Noisy Mobile Ad-Hoc Networks

Broadcasting is used in on-demand routing protocols to discover routes in Mobile Ad-hoc Networks (MANETs). On-demand routing protocols, such as Ad-hoc On-demand Distance Vector (AODV) commonly employ pure flooding based broadcasting to discover new routes. In pure flooding, a route request (RREQ) packet is broadcast by the source node and each receiving node rebroadcasts it. This continues until the RREQ packet arrives at the destination node. Pure flooding generates excessive redundant routing traffic that may lead to the broadcast storm problem (BSP) and deteriorate the performance of MANETs significantly. A number of probabilistic broadcasting schemes have been proposed in the literature to address BSP. However, these schemes do not consider thermal noise and interference which exist in real life MANETs, and therefore, do not perform well in real life MANETs. Real life MANETs are noisy and the communication is not error free. This research argues that a broadcast scheme that considers the effects of thermal noise, co-channel interference, and node density in the neighbourhood simultaneously can reduce the broadcast storm problem and enhance the MANET performance. To achieve this, three investigations have been carried out: First, the effect of carrier sensing ranges on on-demand routing protocol such as AODV and their impact on interference; second, effects of thermal noise on on-demand routing protocols and third, evaluation of pure flooding and probabilistic broadcasting schemes under noisy and noiseless conditions. The findings of these investigations are exploited to propose a Channel Adaptive Probabilistic Broadcast (CAPB) scheme to disseminate RREQ packets efficiently. The proposed CAPB scheme determines the probability of rebroadcasting RREQ packets on the fly according to the current Signal to Interference plus Noise Ratio (SINR) and node density in the neighbourhood. The proposed scheme and two related state of the art (SoA) schemes from the literature are implemented in the standard AODV to replace the pure flooding based broadcast scheme. Ns-2 simulation results show that the proposed CAPB scheme outperforms the other schemes in terms of routing overhead, average end-to-end delay, throughput and energy consumption

ANTMANET: a novel routing protocol for mobile ad-hoc networks based on ant colony optimisation

The core aim of this research is to present “ANTMANET” a novel routing protocol for Mobile Ad-Hoc networks. The proposed protocol aims to reduce the network overhead and delay introduced by node mobility in MANETs. There are two techniques embedded in this protocol, the “Local Zone” technique and the “North Neighbour” Table. They take an advantage of the fact that the nodes can obtain their location information by any means to reduce the network overhead during the route discovery phase and reduced the size of the routing table to guarantee faster convergence. ANTMANET is a hybrid Ant Colony Optimisation-based (ACO) routing protocol. ACO is a Swarm Intelligence (SI) routing algorithm that is well known for its high-quality performance compared to other distributed routing algorithms such as Link State and Distance Vector. ANTMANET has been benchmarked in various scenarios against the ACO routing protocol ANTHOCNET and several standard routing protocols including the Ad-Hoc On-Demand Distance Vector (AODV), Landmark Ad-Hoc Routing (LANMAR), and Dynamic MANET on Demand (DYMO). Performance metrics such as overhead, end-to-end delay, throughputs and jitter were used to evaluate ANTMANET performance. Experiments were performed using the QualNet simulator. A benchmark test was conducted to evaluate the performance of an ANTMANET network against an ANTHOCNET network, with both protocols benchmarked against AODV as an established MANET protocol. ANTMANET has demonstrated a notable performance edge when the core algorithm has been optimised using the novel adaptation method that is proposed in this thesis. Based on the simulation results, the proposed protocol has shown 5% less End-to-End delay than ANTHOCNET. In regard to network overhead, the proposed protocol has shown 20% less overhead than ANTHOCNET. In terms of comparative throughputs ANTMANET in its finest performance has delivered 25% more packets than ANTHOCNET. The overall validation results indicate that the proposed protocol was successful in reducing the network overhead and delay in high and low mobility speeds when compared with the AODV, DMO and LANMAR protocols. ANTMANET achieved at least a 45% less delay than AODV, 60% less delay than DYMO and 55% less delay than LANMAR. In terms of throughputs; ANTMANET in its best performance has delivered 35% more packets than AODV, 40% more than DYMO and 45% more than LANMAR. With respect to the network overhead results, ANTMANET has illustrated 65% less overhead than AODV, 70% less than DYMO and 60 % less than LANMAR. Regarding the Jitter, ANTMANET at its best has shown 60% less jitter than AODV, 55% jitter less than DYMO and 50% less jitter than LANMAR