Performance metrics and routing in vehicular ad hoc networks

The aim of this thesis is to propose a method for enhancing the performance of Vehicular Ad hoc Networks (VANETs). The focus is on a routing protocol where performance metrics are used to inform the routing decisions made. The thesis begins by analysing routing protocols in a random mobility scenario with a wide range of node densities. A Cellular Automata algorithm is subsequently applied in order to create a mobility model of a highway, and wide range of density and transmission range are tested. Performance metrics are introduced to assist the prediction of likely route failure. The Good Link Availability (GLA) and Good Route Availability (GRA) metrics are proposed which can be used for a pre-emptive action that has the potential to give better performance. The implementation framework for this method using the AODV routing protocol is also discussed. The main outcomes of this research can be summarised as identifying and formulating methods for pre-emptive actions using a Cellular Automata with NS-2 to simulate VANETs, and the implementation method within the AODV routing protocol

An optimal path selection using lion optimization routing protocol for mobile ad-hoc network

MANET is a set of nodes that communicate with each other directly or indirectly. The nodes in MANET can be moved freely. The dynamic nature of the network makes several challenges. One of the challenges in routing is to transfer the data from the start node (source) to the end node (destination). Routing suffers from several metrics such as power-consuming, delay, packet delivery ratio, etc. This paper proposed a new protocol called the Lion Optimization Routing protocol (LORP) based on the lion algorithm and AODV protocol. This protocol uses the Lion Optimization Algorithm to select the optimal path. Firstly, we use lion optimization to select the optimal path using the LOA maximization algorithm depending on three main metrics Power Efficiency, Throughput, and Packet Delivery Ratio. Secondly, we use the LOA minimization algorithm to select the optimal path using two metrics Delay and Short Path. In LOA Maximization algorithm metrics calculated and choose the max path value. The result of this protocol is compared with AODV, DSR, and ANTHOCNET

Review of Ad Hoc Networks scenarios and challenges in years 2015-2019

A Mobile Ad-hoc Network (MANET) protocol performance analysis depends on the type of simulation tools, mobility models, and metrics used. These parameters\u27 choice is crucial to researchers because it may produce an inaccurate result if it is not well chosen. The challenges researcher is facing are on the choice of these four parameters. Our survey shows an inclination to used Ad-hoc On-Demand Distance Vector routing (AODV) for performance comparison and enhancement of it by the researcher. Network simulation 2 (NS2) was the most selected tool, but we observe a decline in its utilization in recent years. Random Waypoint Mobility model (RWPM) was the most used mobility model. We have found a high percentage of the published article did not mention the mobility models use; this will make the result difficult for performance comparison with other works. Packet Delivery Ratio (PDR), End to End Delay (E2ED) were the most used metrics. Some authors have self-developed their simulation tools; the authors have also used new metrics and protocols to get a particular result based on their research objective. However, some criteria of choosing a protocol, metrics, mobility model, and simulation tool were not described, decreasing the credibility of their papers\u27 results. Improvement needs to be done in the Ad-hoc network in terms of benchmark, acceptable scenario parameters. This survey will give the best practice to be used and some recommendations to the Ad-hoc network community

An Energy Efficient Routing Based on Route Segmentation in Mobile Ad Hoc Network

Mobile Ad hoc networks based communication is one of an essential form of today's technologies which is highly effective in an emergency need. The feature of infrastructure independence makes it highly useful and versatile all kind of wireless communications needs. But the insufficiency of resources availability degrades its performance and stability of the network. Energy is the vital resource in MANET, as it makes a node to live and retain in-network for longer, which provide better network stability, scalability, and throughput. In this paper, we propose an energy efficient routing based on route segmentation mechanism (EER-RS) for energy saving in the high scalable network. It presents a lightweight route segments energy prediction algorithm to predicts the optimal energy efficiency path for data routing. We evaluate this mechanism in a high scalable network and the obtained results show an improvisation with 40 to 60 percent less energy consumption than traditional AODV and other compared protocol

Polycyclic aromatic hydrocarbons biodegradation using isolated strains under indigenous condition

The treatment and disposal of domestic sIudge is an expensive and environmentally sensitive problem. It is also a growing problem since sludge production will continue to increase as new wastewzter treatment plants are built due to population increase. The large volume of domestic sIudge produced had made it difficult for many countries including Malaysia to assure complete treatment of the sludge before discharging to the receiving environment. Domestic sludge contains diverse range of pollutants such as pathogen, inorganic and organic compounds. These pollutants are toxic, mutagenic or carcinogenic and may threaten human health. Iiilproper disposal and handling of sludge may pose serious impact to the environment especially on soil and water cycles. Previous studies on Malaysian domestic sludge only reported on bulk parameters and heavy metals. Thus, no study reported on organic micro pollutants, namely, polycylic aromatic hydrocarbons (PAHs). Their recalcitrance and persistence make them problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment. Much has been reported on biodegradation of PAHs in several countries but there is a lack of information quantitative on this subject in Malaysia. This study is carried out to understand the nature of domestic sludge and to provide a better understanding on the biodegradation processes of PAHs. The methodology of this study comprised field activities, laboratory work and mathematical modelling. Field activities involved sampling of domestic sludge from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Laboratory activities include seven phases of experimental works. First phase is characterization study of domestic sludge based on bulk parameters, heavy metals and PAHs. Second phase is enrichment and purification of bacteria isolated from domestic sludge using single PAHs and mixed PAHs as growth substrate. This was followed by identification of bacteria using BIOLOG system. The fourth phase focussed on turbidity test to monitor growth rate of the isolated bacteria. Preliminary degradation study involves optimization of the process at different substrate concentration, bacteria concentration, pH and temperature. The optimum conditions established from optimization study were used in degradation study. In biodegradation study, two experimental conditions were performed. These conditions include using bacteria isolated from single PAHs as substrate and bacteria isolated from mixed PAHs. Protein and pH tests were done during degradation study. Final activity is mathematical modelling of the biodegradation process. In general results on bulk parameters are comparable to previous studies. Zinc was the main compound with a mean concentration of 11 96.4 mglkg. PAHs were also detected in all of the samples, with total concentration between 0.72 to 5.36 mglkg dry weight for six PAHs. In the examined samples, phenanthrene was the main compound with a mean concentration of 1.0567 mglkg. The results fiom purification studies of bacteria strains sucessfull isolated 13 bacteria strains fiom single PAH substrate while three bacteria were isolated from the mixed PAHs substrate. Based on bacteria growth rates, only six strains grown on single PAHs and three strains grown on mixed PAHs were used for further studies. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mg~-' of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. The results showed that bacteria grown on lower ring of PAHs are not able to grow on higher ring of PAHs. As for example Micrococcus diversus grown on napthalene as sole carbon source was unable to degrade other PAHs like acenapthylene, acenapthene, fluorene, phenanthrene and antlracene. In the case of bacteria isolated from mixed PAHs, the results showed that most of the napthalene was degraded by isolated strains with the highest average degradation rate followed by acenapthylene, acenapthene, fluorene, phenanthrene and anthracene. 377$3(53867$.$$1�781.8�781�$0,1$+ D4ff + c\,cpda~ition trends were observed in the study could be attributed to the different subsr , i,lo\~ir 'Led during isolation process. Interaction through cometabolism and synergistic ocolq bacteria strains isolated from single substrate. Thus, only synergistic interaction was oL, :a 77ed for bacteria isolated from mixed substrate. Corynebacterium urolyticum re\e;;ed I,, be the best strain in degrading PAHs. The experimental results have led to a model conccl~t desclibing I'AHs degradation

A survey of performance enhancement of transmission control protocol (TCP) in wireless ad hoc networks

This Article is provided by the Brunel Open Access Publishing Fund - Copyright @ 2011 Springer OpenTransmission control protocol (TCP), which provides reliable end-to-end data delivery, performs well in traditional wired network environments, while in wireless ad hoc networks, it does not perform well. Compared to wired networks, wireless ad hoc networks have some specific characteristics such as node mobility and a shared medium. Owing to these specific characteristics of wireless ad hoc networks, TCP faces particular problems with, for example, route failure, channel contention and high bit error rates. These factors are responsible for the performance degradation of TCP in wireless ad hoc networks. The research community has produced a wide range of proposals to improve the performance of TCP in wireless ad hoc networks. This article presents a survey of these proposals (approaches). A classification of TCP improvement proposals for wireless ad hoc networks is presented, which makes it easy to compare the proposals falling under the same category. Tables which summarize the approaches for quick overview are provided. Possible directions for further improvements in this area are suggested in the conclusions. The aim of the article is to enable the reader to quickly acquire an overview of the state of TCP in wireless ad hoc networks.This study is partly funded by Kohat University of Science & Technology (KUST), Pakistan, and the Higher Education Commission, Pakistan

Auro: Adaptive Unicast Routing Framework for Vehicular Ad Hoc Network

A special type of Mobile Ad hoc network (MANET) is Vehicular Ad hoc Network (VANET) and it provides exchange of messages between vehicles. VANET encourages researchers to create safety and comfort applications that will lead to Intelligent Transport Systems (ITS). Link failure in the routing path occurs due to frequent change in the network topology of VANET. To handle this situation, the routing protocol has to initiate either a local repair of route or find a route by broadcasting control overhead packets. This increases the network bandwidth utilization of the VANET. When the number of vehicles increase in VANET, broadcasting of redundant route repair packets increases the collisions in the medium leading to broadcasting storm problem. This paper proposes an Adaptive Unicast ROuting (AURO) framework to address frequent disconnections and broadcast storm problems in VANET. This framework selects suitable protocol from the three unicast routing protocols namely On-demand Proactive with Route Maintenance Protocol (ORPM), Efficient Reactive routing Protocol (ERP) and Stable Routing Protocol (SRP) from the network context and the user requirements. The proposed AURO framework is implemented using NS2 and SUMO simulators. The performance of these protocols were thoroughly analyzed and compared with existing popular protocols

Toward Constructive Relay-Based Cooperative Routing in MANETs

Frequent link breaks (due to node mobility) and quick exhaustion of energy (due to limited battery volume) are two major problems impacting on the flexibility in mobile ad hoc networks (MANETs). Cooperative communication in MANETs has become an appealing topic, as it can improve system capacity and energy efficiency. In spite of such advantages of cooperative communication, some issues still remain, such as the lack of a systematically designed cooperative routing scheme (including route discovery, route reply, route enhancement, and cooperative data forwarding), facilitation of cooperative communication in mobility resistance, and route selection (jointly considering energy consumption, energy-harvesting ability, and link break probability). Driven by the above concerns, we propose a novel Constructive-Relay-based CooPerative Routing (CRCPR) protocol in this paper. Using topological information stored and maintained in a COoPerative Table and Relay Table, CRCPR enhances resilience to mitigate the mobility issue by self-managing to construct adequate relays for data forwarding. Furthermore, assuming nodes are mostly battery operated, CRCPR proposes a new route selection mechanism, which takes into account energy consumption, energy harvesting, and link break probability, to determine an appropriate route across a network. Simulation results show the robustness of CRCPR against node mobility, further with improvement for up to 60% network throughput and 40% prolonged network lifetime