A comparative study of routing protocols in MANETs

Mobile Ad Hoc networks are emerging area of mobile computing. A mobile ad hoc network (MANET) is composed of mobile routers and associated hosts connected by wireless links. The routers are free to move randomly and organize themselves arbitrarily, thus, the network\u27s wireless topology may change rapidly and unpredictably. In fact, it is considered that each node would have some capacity to relay the information thus constrained by computational power, battery life and increasingly complex routing with added functionality of a router. Nodes may keep joining and leaving an ad hoc network. Such a network may operate in a stand alone fashion, or may be connected to the larger Internet. Lack of infrastructure in ad hoc networks sets new challenges for routing algorithms where the network is formed by a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. A number of routing protocols like Dynamic Source Routing (DSR), Ad Hoc On-Demand Distance Vector Routing (AODV), Destination-Sequenced Distance-Vector (DSDV), Zone Routing Protocol (ZRP) and Temporally Ordered Routing Algorithm (TORA) have been implemented. In this thesis an attempt has been made to compare the performance of prominent on-demand reactive routing protocols for mobile ad hoc networks (AODV and TORA), along with the traditional proactive DSDV protocol. Although AODV and TORA share similar on-demand behavior, the differences in the protocol mechanics can lead to significant performance differentials. The performance differentials are analyzed using varying network loads, mobilities, and network sizes. These simulations are carried out using network simulator (ns-2.1b9a) to run mobile ad hoc network simulations

Novel Method of Improving Quality of Service for Voice over Internet Protocol Traffic in Mobile Ad Hoc Networks

In recent years, the application of Mobile Ad-hoc Network (MANET) with Voice over Internet Protocol (VoIP) has been increased.  However, the level of Quality of Service (QoS) for VoIP traffic in MANET, while there is no infrastructure, will reduce when dealing with a large number of calls. In this type of dynamic environment, the developing of a new infrastructure becomes more costly and time-consuming. In this paper, we proposed an efficient method, called the Quality of Service-Nearest Neighbor (QoS-NN), to improve the QoS level for VoIP in order to manage the huge number of calls over MANET network. We utilized the Ad-hoc On-demand Distance Vector (AODV) protocol as the underlying routing protocol to implement our proposed method. We evaluated the proposed QoS-NN method using Network Simulator version 2 (NS2). The performance of the proposed QoS-NN method was compared with Lexicographic order method. The comparison was evaluated in terms of R-factor, end-to-end delay, packet loss ratio, and packet delivery ratio performance metrics. In addition, the proposed method evaluated under different network parameters such as VoIP CODECs, node mobility speed, number of calls and number of nodes. The comparison results indicate that the proposed QoS-NN outperform the Lexicographic order method

SIMULATION AND ANALYSIS OF VEHICULAR AD-HOC NETWORKS IN URBAN AND RURAL AREAS

According to the American National Highway Traffic Safety Administration, in 2010, there were an estimated 5,419,000 police-reported traffic crashes, in which 32,885 people were killed and 2,239,000 people were injured in the US alone. Vehicular Ad-Hoc Network (VANET) is an emerging technology which promises to decrease car accidents by providing several safety related services such as blind spot, forward collision and sudden braking ahead warnings. Unfortunately, research of VANET is hindered by the extremely high cost and complexity of field testing. Hence it becomes important to simulate VANET protocols and applications thoroughly before attempting to implement them. This thesis studies the feasibility of common mobility and wireless channel models in VANET simulation and provides a general overview of the currently available VANET simulators and their features. Six different simulation scenarios are performed to evaluate the performance of AODV, DSDV, DSR and OLSR Ad-Hoc routing protocols with UDP and TCP packets. Simulation results indicate that reactive protocols are more robust and suitable for the highly dynamic VANET networks. Furthermore, TCP is found to be more suitable for VANET safety applications due to the high delay and packet drop of UDP packets.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Detecting Non-Line of Sight to Prevent Accidents in Vehicular Ad hoc Networks

There are still many challenges in the field of VANETs that encouraged researchers to conduct further investigation in this field to meet these challenges. The issue pertaining to routing protocols such as delivering the warning messages to the vehicles facing Non-Line of Sight (NLOS) situations without causing the storm problem and channel contention, is regarded as a serious dilemma which is required to be tackled in VANET, especially in congested environments. This requires the designing of an efficient mechanism of routing protocol that can broadcast the warning messages from the emergency vehicles to the vehicles under NLOS, reducing the overhead and increasing the packet delivery ratio with a reduced time delay and channel utilisation. The main aim of this work is to develop the novel routing protocol for a high-density environment in VANET through utilisation of its high mobility features, aid of the sensors such as Global Positioning System (GPS) and Navigation System (NS). In this work, the cooperative approach has been used to develop the routing protocol called the Co-operative Volunteer Protocol (CVP), which uses volunteer vehicles to disseminate the warning message from the source to the target vehicle under NLOS issue; this also increases the packet delivery ratio, detection of NLOS and resolution of NLOS by delivering the warning message successfully to the vehicle under NLOS, thereby causing a direct impact on the reduction of collisions between vehicles in normal mode and emergency mode on the road near intersections or on highways. The cooperative approach adopted for warning message dissemination reduced the rebroadcast rate of messages, thereby decreasing significantly the storm issue and the channel contention. A novel architecture has been developed by utilising the concept of a Context-Aware System (CAS), which clarifies the OBU components and their interaction with each other in order to collect data and take the decisions based on the sensed circumstances. The proposed architecture has been divided into three main phases: sensing, processing and acting. The results obtained from the validation of the proposed CVP protocol using the simulator EstiNet under specific conditions and parameters showed that performance of the proposed protocol is better than that of the GRANT protocol with regard to several metrics such as packet delivery ratio, neighbourhood awareness, channel utilisation, overhead and latency. It is also successfully shown that the proposed CVP could detect the NLOS situation and solves it effectively and efficiently for both the intersection scenario in urban areas and the highway scenario

Analysis of Black hole Attack in Ad hoc On-Demand Distance Vector (AODV) Routing Protocol : Vehicular Ad-hoc Networks (VANET) Context

In past years, popularity of Mobile Ad hoc Networks has led to the conception of Vehicular Ad hoc Networks. These networks must be highly secure before their implementation in real world. One of the vital aspects of these networks is routing protocol. Most of the protocols in VANET acknowledge all nodes in a network to be genuine by default. But there might be malicious nodes which can make the network vulnerable to various attacks. One such attacks is a black hole attack on AODV routing protocol. Because of its popularity, AODV and black hole attack are taken into consideration for this thesis. The aim of the thesis is to analyze effects of black hole attack on AODV and understand security need of routing protocols in VANET. The experimentation for this thesis was performed with 40, 60 and 80 nodes in network simulator (NS). The performance metrics such as average throughput, end to end delay and packet delivery ratio of each assumed scenarios under blackhole attack and with prevention method are calculated. The obtained calculations are compared to analyze the network performance of AODV. The results from the simulator demonstrate that overall network performance of AODV increased with black hole prevention algorithm in comparison to AODV under black hole attack only. Out of all the performance metrics that are used to analyze the network performance, the average throughput of AODV is significantly increased by 21 percent (approximately) when the mitigation algorithm is applied. The prevention approach used for the thesis can make AODV perform better against black hole attack. However, this approach is limited to a small to medium sized networks only

Information collection algorithm for vehicular ad-hoc networks (application domain: Urban Traffic Wireless Vehicular Ad-Hoc Networks (VANETs))

Vehicle to vehicle communication (V2VC) is one of the modern approaches for exchanging and generating traffic information with (yet to be realized) potential to improve road safety, driving comfort and traffic control. In this research, we present a novel algorithm which is based on V2V communication, uses in-vehicle sensor information and in collaboration with the other vehicles' sensor information can detect road conditions and determine the geographical area where this road condition exists – e.g. geographical area where there is traffic density, unusual traffic behaviour, a range of weather conditions (raining), etc. The algorithms' built-in automatic geographical restriction of the data collection, aggregation and dissemination mechanisms allows warning messages to be received by any car, not necessarily sharing the identified road condition, which may then be used to identify the optimum route taken by the vehicle e.g. avoid bottlenecks or dangerous areas including accidents or congestions on their current routes. This research covers the middle ground between MANET [1] and collaborative data generation based on knowledge granularity (aggregation). It investigates the possibility of designing, implementing and modelling of the functionality of an algorithm (as part of the design of an intelligent node in an Intelligent Transportation System - ITS) that ensures active participation in the formation, routing and general network support of MANETs and also helps in-car traffic information and real-time control generation and distribution. The work is natural extension of the efforts of several large EU projects like DRIVE [2], GST [3] and SAFESPOT [4]

SURVEY STUDY FOR VEHICULAR AD HOC NETWORKS PERFORMANCE IN CITY AND URBAN RESIDENTIAL AREAS

This thesis it survey study for VANET (Vehicular Ad-Hoc Networks) and it performance in city and urban residential areas, when the the number of vehicles on roads is increasing annually, due to the higher amount of traffic, there are more accidents associated with road traffic complexity. VANET can be used to detect dangerous situations which are forwarded to the driver assistant system by monitoring the traffic status.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Enhanced Load Balanced Clustering Technique for VANET Using Location Aware Genetic Algorithm

The vehicular Adhoc Network has unique charac-teristics of frequent topology changes, traffic rule-based node movement, and speculative travel pattern. It leads to stochastic unstable nature in forming clusters. The re-liable routing process and load balancing are essential to improve the network lifetime. Cluster formation is used to split the network topology into small structures. The reduced size network leads to accumulating the topology information quickly. Due to the absence of centralised management, there is a pitfall in network topology man-agement and optimal resource allocation, resulting in ineffective routing. Hence, it is necessary to develop an effective clustering algorithm for VANET. In this paper, the Genetic Algorithm (GA) and Dynamic Programming (DP) are used in designing load-balanced clusters. The proposed Angular Zone Augmented Elitism-Based Im-migrants GA (AZEIGA) used elitism-based immigrants GA to deal with the population and DP to store the out-come of old environments. AZEIGA ensures clustering of load-balanced nodes, which prolongs the network lifetime. Experimental results show that AZEIGA works appreciably well in homogeneous resource class VANET. The simulation proves that AZEIGA gave better perfor-mance in packet delivery, network lifetime, average de-lay, routing, and clustering overhead