Ongoing research suggests decentralized solutions based on blockchain for vehicle sharing scenario, to solve the fairness and privacy violation issues in centralized platforms. Users can transfer funds and execute decentralized applications, called smart contracts, in these blockchain­based platforms. Among them, several smart contract schemes are designed for the booking and payment functionality, e.g. dPACE [21] and Sc2Share [50]. Renters and vehicle owners can directly interact with these deployed smart contracts and finish booking, driving and payment, combined with existing vehicle access protocols like HERMES [66]. However, current smart contracts for booking and payment only consider to be executed on the root chain, called Layer­1. In this way, the execution waiting times are too long and transaction fees incurred by the blockchain are too high. Such problems in vehicle sharing can be mitigated by executing smart contracts on Layer­ 2 of blockchain, which is an efficient off­chain technology whose purpose is to scale blockchain transaction capacity while retaining the decentralization benefits of the blockchain. This thesis aims to build a smart contract for booking and payment in vehicle sharing scenario, and use different Layer­2 technologies to test it. First, we design an improved smart contract based the Sc2Share’s structure. The improved points are: 1. Store previous renters’ information, including deposit amount and other booking details, to support sustainable usage in each vehicle. 2. Optimize dispute settlement, to handle malicious behaviors in rental process. 3. Add more events emission for better monitoring the state of vehicle. Then, we pick four representative Layer­2 schemes in latest Layer­2 technologies to compare fee costs. Our smart contract is tested on the representative schemes and a comparison between them is sorted out. We follow the whole steps in booking and payment to measure the performance and fee cost between different Layer­2 schemes. Besides, we also execute the smart contract on Layer­1 as a comparison. The result shows that the contract is executed at different costs in different Layer­2 technologies, but the costs are significantly lower and executions confirmation are faster than Layer­1. This implies that our smart contract with Layer­2 technologies can mitigate the problems mentioned before. / Pågående forskning föreslår decentraliserade lösningar baserade på blockchain för rättvisa och integritetsproblem i centraliseradeplattformar. Användare kan överföra pengar och köra decentraliserade applikationer, så kallade smarta kontrakt, i dessa blockchain­baserade plattformar. Bland dem är flera smarta avtalsscheman designade för boknings­och betalningsfunktionaliteten, e.g. dPACE [21] och Sc2Share [50]. Hyresgäster och fordonsägare kan interagera direkt med dessa implementerade smarta kontrakt och avsluta bokning, körning och betalning, kombinerat med befintliga fordonsåtkomstprotokoll som HERMES [66]. Men nuvarande smarta kontrakt för bokning och betalning anses endast utföras på rotkedjan, kallad Layer­1. På så sätt blir exekveringsväntetiderna för långa och transaktionsavgifterna för blockkedjan för höga. Sådana problem i fordonsdelning kan mildras genom att utföra smarta kontrakt på Layer­2 av blockchain, som är en effektiv off­chain­teknologi vars syfte är att skala blockchain­transaktionskapaciteten samtidigt som blockkedjans decentraliseringsfördelar bibehålls. Detta examensarbete syftar till att bygga ett smart kontrakt för bokning och betalning i fordonsdelningsscenariot, och använda olika Layer­2­teknologier för att testa det. Först designar vi ett förbättrat smart kontrakt baserat på Sc2Shares struktur. De förbättrade punkterna är: 1. Lagra tidigare hyresgästers information, inklusive depositionsbelopp och andra bokningsdetaljer, för att stödja hållbar användning i varje fordon. 2. Optimera tvistlösning för att hantera skadligt beteende i uthyrningsprocessen. 3. Lägg till fler händelseutsläpp för bättre övervakning av fordonets tillstånd. Sedanväljer vi fyra representativa Layer­2­scheman i de senaste Layer­2­teknologierna för att jämföra avgiftskostnaderna. Vårt smarta kontrakt testas på representativa system och en jämförelse mellan dem reds ut. Vi följer hela stegen i bokning och betalning för att mäta prestanda och avgiftskostnad mellan olika Layer­2­scheman. Dessutom utför vi också det smarta kontraktet på Layer­1 som en jämförelse. Resultatet visar att kontraktet utförs till olika kostnader i olika Layer­2­teknologier, men kostnaderna är betydligt lägre och utförandebekräftelsen går snabbare än Layer­1. Detta innebär att vårt smarta kontrakt med Layer­2­teknologier kan mildra de problem som nämnts tidigare.

[pt] O estudo da dinâmica lateral é de grande importância para análise do comportamento de um veículo durante manobras e fundamental para a implementação de sistemas de controle de estabilidade e de trajetória em veículos autônomos. Nesse contexto, baseado em medições experimentais de um veículo militar de três eixos durante manobras de mudança dupla de faixa a diferentes velocidades, o presente trabalho apresenta métodos de identificação de sistemas para obtenção de modelos lineares por meio da ferramenta CONTSID (CONTinuous-Time System IDentification), disponível no MATLAB; de modelos não lineares baseados em Redes Neurais; e, por fim, a proposta de emprego de modelos híbridos com o intuito de minimizar o erro associado à primeira abordagem, somando-se ao modelo linear, o valor estimado do resíduo com a aplicação de redes neurais. Por se tratarem de modelos obtidos a partir de dados observados, como parâmetros de entrada e de saída do sistema, foram selecionados o ângulo do volante e a taxa de guinada do veículo, respectivamente. Com a utilização do dados observados, foi realizada a identificação das funções de transferência para cada velocidade, o que possibilitou a análise da influência dessa variável no comportamento dinâmico do sistema. Em seguida, empregou-se uma abordagem via redes neurais ao mesmo conjunto de dados, com a construção de arquiteturas distintas por meio da modificação do número de neurônios, número de camadas e função de ativação. Por fim, um modelo híbrido foi combinado utilizando-se a modelagem linear e não linear para obtenção de melhorias na resposta do modelo final estimado. De acordo com os resultados, as técnicas empregadas apresentaram viabilidade de aplicação e resultados satisfatórios, destacando-se o aprimoramento do modelo linear por meio de sua substituição pelo modelo híbrido baseado em redes neurais. Do exposto, objetiva-se destacar o potencial dos métodos apresentados de forma que, posteriormente, esses estudos possam ser aprofundados para implementação de malhas de controle veicular, com o intuito de contribuir com o aumento da segurança, melhoria do conforto e no desenvolvimento de veículos autônomos. / [en] The study of lateral dynamics is of great importance for the vehicle behavior analysis during turning maneuvers, and it is fundamental to stability or path control systems used in autonomous vehicles. In this context, based on experimental measurements of a three-axle military wheeled vehicle during double lane changes maneuvers at different speed, this work presents methods for the identification of linear models using the CONTSID (CONTinuous-Time System IDentification) toolbox, available in MATLAB; nonlinear models based on artificial neural networks; and, the application of hybrid models to reduce the error associated with the first approach, combining the linear model to the estimated error using neural networks. Since those are data-driven methods, as input and output parameters of the system, the wheel steering angle and the yaw rate of the vehicle were respectively selected. Using the CONTSID toolbox, the identification of the transfer functions for each speed was performed, making it possible to evaluate the influence of this variable in the system s dynamics behavior. Thereafter, a neural network approach was applied to the same data set, changing architecture s parameters, such as number of neurons, layers and the activation function. At last, a hybrid model approach was presented through the combination of previous linear and nonlinear approaches to improve the estimated model response. The proposed methods showed satisfatory results, highlighting the improvement in the linear model through its replacement by the hybrid model based on neural networks. Therefore, this work aims to show the potential of the methods presented, and posteriorly contribute to studies on the implementation of vehicle control systems to increase safety, improve comfort and in the development of autonomous vehicles.

No description available.

The technological advancements in the automotive industry as well as in thefield of communication technologies done the last years have transformed thevehicles to complex machines that include not only electrical and mechanicalcomponents but also a great number of electronic components. Furthermore,modern vehicles are now connected to the Wide Area Network (WAN) and inthe near future communications will also be present between the cars (Vehicleto-Vehicle, V2V) and between cars and infrastructure (Vehicle-to-Infrastructure, V2I), something that can be found as Internet of Vehicles (IoV)in the literature. The main motivations towards all the aforementioned changesin modern vehicles are of course the improvement of road safety, the higherconvenience of the passengers, the increase in the efficiency and the higher userfriendliness.On the other hand, having vehicles connected to the Internet opens them up toa new domain of interest, this no other than the domain of cyber security. Thispractically means that while previously we were only considering cyber-attackson computational systems, now we need to start thinking about it also forvehicles. This, as a result, creates a new field of research, namely the vehicularcyber security. However, this field does not only include the possible vehicularcyber-attacks and their corresponding defenses but also the modeling andsimulation of them with the use of vehicular security analysis tools, which isalso recommended by the ENISA report titled “Cyber Security and Resilienceof smart cars: Good practices and recommendations”.Building on this need for vehicular security analysis tools, this work aims tocreate and evaluate a domain-specific, probabilistic modeling and simulationlanguage for cyber-attacks on modern connected vehicles. The language will bedesigned based on the existing threat modeling and risk management toolsecuriCAD® by foreseeti AB and more specifically based on its underlyingmechanisms for describing and probabilistically evaluating the cyber threats ofthe models.The outcome/final product of this work will be the probabilistic modeling andsimulation language for connected vehicles, called vehicleLang, that will beready for future use in the securiCAD® software. / De tekniska framstegen inom fordonsindustrin såväl som inomkommunikationsteknik som gjorts de senaste åren har omvandlat fordon tillkomplexa maskiner som inte bara omfattar elektriska och mekaniskakomponenter utan också ett stort antal elektroniska komponenter. Dessutom ärmoderna fordon nu anslutna till Internet (WAN) och inom den närmasteframtiden kommer kommunikation också att etableras mellan bilarna (Vehicleto-Vehicle, V2V) och mellan bilar och infrastruktur (Vehicle-to-Infrastructure,V2I). Detta kan också kallas fordonens internet (Internet of Vehicles - IoV) ilitteraturen. De främsta motiven för alla ovannämnda förändringar i modernafordon är förstås förbättringen av trafiksäkerheten, ökad bekvämlighet förpassagerarna, ökad effektivitet och högre användarvänlighet.Å andra sidan, att ha fordon anslutna till Internet öppnar dem för en ny domän,nämligen cybersäkerhet. Då vi tidigare bara övervägde cyberattacker påtraditionella datorsystem, måste vi nu börja tänka på det även för fordon. Dettaområde omfattar emellertid inte bara de möjliga fordonsattackerna och derasmotsvarande försvar utan även modellering och simulering av dem med hjälpav verktyg för analys av fordonssäkerhet, vilket också rekommenderas avENISA-rapporten med titeln ”Cyber Security and Resilience of smart cars: Goodpractices and recommendations”.På grund av detta behov av verktyg för fordonssäkerhetsanalys syftar dettaarbete till att skapa och utvärdera ett domänspecifikt, probabilistisktmodelleringsspråk för simulering av cyberattacker på moderna anslutna fordon.Språket har utformats utifrån det befintliga hotmodellerings- ochriskhanteringsverktyget securiCAD® av foreseeti AB och mer specifikt baseratpå dess underliggande mekanismer för att beskriva och probabilistiskt utvärderamodellernas cyberhot.Resultatet/slutprodukten av detta arbete är ett probabilistisktmodelleringsspråk för uppkopplade fordon, vehicleLang.

Platooning has the potential to be a breakthrough in increasing road capacity and reducing fuel consumption, as it allows a chain of vehicles to closely follow each other on the road. When the number of vehicles increases, platoons will follow one another in what is referred to as multiplatooning. Many Cooperative Intelligent Transportation Systems (C-ITS) applications rely on periodically exchanged beacons among vehicles to improve traffic safety. However, as the number of connected vehicles increases, the network may become congested due to periodically exchanged beacons. Therefore, without some congestion control method, safety critical messages such as Cooperative Awareness Messages (CAMs) may not be delivered on time in high vehicle density scenarios. Both the European Telecommunications Standards Institute (ETSI) and the Institute of Electrical and Electronics Engineers (IEEE) have been working on different standards to support vehicular communication. ETSI dened the Decentralized Congestion Control (DCC) mechanism which adapts transmission parameters (message rate, transmit data rate, and transmit power, etc.) to keep channel load under control. ETSI DCC utilizes a three-state machine with RELAXED, ACTIVE, and RESTRICTIVE states. In this thesis, we implemented this three-state machine by adapting the message rate based on the channel busy ratio (CBR). We name this message-rate based three-state machine DCC-3. DCC-3 has the ability to control channel load; however, it has unfairness and instability problems due to the dramatic parameter changes between states. Therefore, we divided the ACTIVE state of DCC-3 into ve sub-states, and refer to this as DCC-7. We benchmarked DCC-3 against static beaconing (STB), dynamic beaconing (DynB), LInear MEssage Rate Integrated Control (LIMERIC), and DCC-7 using different evaluation metrics with different numbers of platoons. Our results from the Plexe simulator demonstrate that DCC-7 has the best performance when considering all evaluation metrics, including CBR, Inter-reception time (IRT), collisions, safe time ratio, and fairness. Furthermore, we found using transmit power control could greatly improve the performance of CBR and collision rates. / Platooning (fordonskonvojer) har potential att bli ett genombrott i öka vägkapaciteten och minska bränsleförbrukning, eftersom det tillåter en kedja av fordon att noga följa varandra på vägen. När antalet fordon ökar, kommer att plutoner följa varandra i vad som benämns multiplatooning (konvoj av fordonskonvojer). Många kooperativ intelligenta transportsystem (C-ITS) tillämpningar förlitar sig på regelbundet utbytte beacons bland fordon att förbättra traffiksäkerheten. Dock som antalet uppkopplade fordon ökar, kan nätverket bli överbelastat på grund av regelbundet utbytte beacons. Utan någon trängsel kontrollmetod, får därför säkerhet kritiska meddelanden såsom kooperativ medvetenhet meddelanden (CAMs) inte levereras i tid i höga fordon densitet scenarier. Både Europeiska institutet för telekommunikationsstandarder (ETSI) och Institute el och elektroniska tekniker (IEEE) har arbetat på olika standarder för att stödja vehicular kommunikation. ETSI definieras den decentraliserade överbelastning kontroll (DCC) mekanism som anpassar överföring parametrar (meddelande hastighet, överföra datahastighet och sändningseffekt, etc.) för att hålla kanalen belastningen under kontroll. ETSI DCC använder en tre-state maskin med RELAXED, ACTIVE och RESTRICTIVE stater. I denna avhandling har genomfört vi denna tre-state maskin genom att anpassa meddelande hastighet baserat på kanal upptagen förhållandet (CBR). Vi nämna detta meddelande-hastighet baserat tre-state machine DCC-3. DCC-3 har förmågan att kontrollera kanal belastning; Det har dock otillbörlighet och instabilitet problem på grund av de dramatiska parameterändringar mellan stater. Därför vi indelat det ACTIVE tillståndet för DCC-3 i fem undertillstånd och hänvisar till detta som DCC-7. Vi benchmarkade DCC-3 mot statiska leda (STB), dynamisk leda (DynB), linjära MEssage Rate integrerad kontroll (LIMERIC) och DCC-7 med olika utvärdering statistik med olika antal plutoner. Våra resultat från Plexe simulator visar att DCC-7 har bästa prestanda när man överväger alla utvärdering statistik, inklusive CBR, mellan receptionen tid (IRT), kollisioner, säker tid baserat och rättvisa. Vi fann dessutom använda Sändareffektstyrning kan avsevärt förbättra prestanda för CBR och kollision priser.

Vehicular ad hoc network (VANET) is a special case of mobile networks, where vehicles equipped with computing/communicating devices (called "smart vehicles") are the mobile wireless nodes. However, the movement pattern of these mobile wireless nodes is no more random, as in case of mobile networks, rather it is restricted to roads and streets. Vehicular networks have hybrid architecture; it is a combination of both infrastructure and infrastructure-less architectures. The direct vehicle to vehicle (V2V) communication is infrastructure-less or ad hoc in nature. Here the vehicles traveling within communication range of each other form an ad hoc network. On the other hand, the vehicle to infrastructure (V2I) communication has infrastructure architecture where vehicles connect to access points deployed along roads. These access points are known as road side units (RSUs) and vehicles communicate with other vehicles/wired nodes through these RSUs. To provide various services to vehicles, RSUs are generally connected to each other and to the Internet. The direct RSU to RSU communication is also referred as I2I communication. The success of VANET depends on the existence of pervasive roadside infrastructure and sufficient number of smart vehicles. Most VANET applications and services are based on either one or both of these requirements. A fully matured VANET will have pervasive roadside network and enough vehicle density to enable VANET applications. However, the initial deployment stage of VANET will be characterized by the lack of pervasive roadside infrastructure and low market penetration of smart vehicles. It will be economically infeasible to initially install a pervasive and fully networked iv roadside infrastructure, which could result in the failure of applications and services that depend on V2I or I2I communications. Further, low market penetration means there are insufficient number of smart vehicles to enable V2V communication, which could result in failure of services and applications that depend on V2V communications. Non-availability of pervasive connectivity to certification authorities and dynamic locations of each vehicle will make it difficult and expensive to implement security solutions that are based on some central certificate management authority. Nonavailability of pervasive connectivity will also affect the backend connectivity of vehicles to the Internet or the rest of the world. Due to economic considerations, the installation of roadside infrastructure will take a long time and will be incremental thus resulting in a heterogeneous infrastructure with non-consistent capabilities. Similarly, smart vehicles will also have varying degree of capabilities. This will result in failure of applications and services that have very strict requirements on V2I or V2V communications. We have proposed several solutions to overcome the challenges described above that will be faced during the initial deployment stage of VANET. Specifically, we have proposed:  A VANET architecture that can provide services with limited number of heterogeneous roadside units and smart vehicles with varying capabilities.  A backend connectivity solution that provides connectivity between the Internet and smart vehicles without requiring pervasive roadside infrastructure or large number of smart vehicles.  A security architecture that does not depend on pervasive roadside infrastructure or a fully connected V2V network and fulfills all the security requirements. v  Optimization solutions for placement of a limited number of RSUs within a given area to provide best possible service to smart vehicles. The optimal placement solutions cover both urban areas and highways environments

According to a Gartner Group (www.gartner.com) report in September 2008, the worldwide telecommunications market is on pace to reach $2 trillion in 2008. Gartner predicts that by 2012, the ratio of mobile to fixed connections will exceed 4-to-1. The North American mobile data market grew to 141.1 million connections in 2007, with a compound annual growth rate of 41.7 percent. It is believed that a large portion will be ad hoc and multi-hop connections, which will open many opportunities for Mobile Ad hoc NETwork (MANET) applications and Wireless Mesh Network (WMN) applications. A MANET is a self-organizing multi-hop wireless network where all nodes participate in the routing and data forwarding process. Such a network can be easily deployed in situations where no base station is available, and a network must be build spontaneously. In applications such as battlefield communications, national crises, disaster recovery, and sensor deployment, a wired network is not available and ad hoc networks provide the only feasible means of communications and information access. Ad hoc networks have also become commonplace for gaming, conferencing, electronic classrooms, and particularly vehicle-to-vehicle communications. A Wireless mash network (WMN) is collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. Their rapid deployment and ease of maintenance are suitable for on-demand network such as disaster recovery, homeland security, convention centers, hard-to-wire buildings and unfriendly terrains. One important problem with MANET is the routing protocol that needs to work well not just with a small network, but also sustain efficiency and scalability as the network gets expanded and the application transmits data in greater volume. In such an environment, mobility, channel error, and congestion are the main causes for packet loss. Due to mobility of mobile hosts, addressing frequent and unpredictable topology changes is fundamental to MANET research. Two general approaches have been considered: connection-oriented approach and connectionless-oriented approach. In the former, the emphasis is on how to reconnect quickly with low overhead when a broken link occurs. Examples of this approach includes includes [5], [9], [10], [16], [26], [28], [29], [34], [44], and [45]. In contrast, connectionless-oriented approach focuses on minimizing the occurrence of broken links. We proposed one such scheme called Connectionless Approach (CLA) and . In CLA, the network area is divided into non-overlapping grid cells, each serving as a virtual router. Any physical router (i.e., mobile host), currently inside a virtual router, can help forward the data packet to the next virtual router along the virtual link. This process is repeated until the packet reaches its final destination. Since a virtual link is based on virtual routers which do not move, it is much more robust than physical links used in the connection-oriented techniques. Simulation results in our previous works and , based on GloMoSim , indicate that CLA performs significantly better than connection-oriented techniques (i.e., AODV, DSR, LAR, GRID, TMNR, and GPSR). The contribution of this work consists of investigating and developing new Connectionless-Oriented Approach for Mobile Ad Hoc Network. Two of the greatest impacts of this research are as follows. First, the new approach is targeted towards robustly support high mobility and large scale environment which has been adapted for vehicle-to-vehicle environment in . Second, the detailed simulations which compare eight representative routing protocols, namely AODV, DSR, LAR, GRID, TMNR, GPSR, CBF, and CLA, under high-mobility environments. As many important emergent applications of the technology involved high-mobility nodes, very little is known about the existing routing methods perform relative to each other in high-mobility environments. The simulation results provide insight into ad hoc routing protocols and offer guidelines for mobile ad hoc network applications. Next, we enhanced and extend the connectionless-oriented approach. The current connectionless-oriented approach, however, may suffer from packet drops since traffic congestion is not considered in the packet forwarding policy. We address this weakness by considering the connectionless-oriented approach with a collision avoidance routing technique. After that, we investigate techniques to enforce collaboration among mobile devices in supporting the virtual router functionality. Many works have been published to combat such problem - misbehaving nodes are detected and a routing algorithm is employed to avoid and penalize misbehaving nodes. These techniques, however, cannot be applied to the connectionless-oriented approach since any node in the general direction towards the destination node can potentially help forward the data packets. To address the security and cooperation issues for connectionless-oriented approach, we introduce a cooperation enforcement technique called 3CE (3-Counter Enforcement). In addition, wireless mesh networks have become increasingly popular in recent years. Wireless mash network (WMNs) are collection of mesh clients and mesh nodes (routers), with mesh nodes forming the backbone of the network and providing connection to the Internet and other network. We propose a paradigm that combines virtual routers and mesh nodes to create a hybrid network call VR-Mesh Network. This hybrid network can reduce number of mesh node needed without decrease the performance of the network.

With recent advances in technology, Vehicular Ad-hoc Networks (VANETs) have grown in application. One of these areas of application is Vehicle Safety Communication (VSC) technology. VSC technology allows for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications that enhance vehicle safety and driving experience. However, these newly developing technologies bring with them a concern for the vehicular privacy of drivers. Vehicles already employ the use of pseudonyms, unique identifiers used with signal messages for a limited period of time, to prevent long term tracking. But can attackers still attack vehicular privacy even when vehicles employ a pseudonym change strategy? The major contribution of this paper is a new attack model that uses long-distance pseudonym changing and short-distance non-changing protocols to associate vehicles with their respective pseudonyms.

Future mines will benefit from connected intelligent transport system technologies. Autonomous mining vehicles will improve safety and productivity while decreasing the fuel consumption. Hence, it is necessary for Scania to increase the know-how regarding the design of vehicular communication systems for the harsh mine environment. The scope of this work is to examine the requirements for the antenna placement of a future autonomous mining truck and propose suitable antenna types and positions. By using the electromagnetic simulator suite CST Microwave Studio, the research estimates the impact of a simplified autonomous mining vehicle geometry on basic antenna radiation patterns. Some simulated antenna configurations are assessed with radiation pattern measurements. In order to radiate enough power towards the area surrounding the vehicle and guarantee reliable communications, the truck requires omnidirectional antennas in centered locations, or alternatively one patch antenna for each side. The method used to solve the problem is also assessed: flexibility provided by the simulation method is emphasized, whereas some relevant limitations are discussed. Hardware requirements, availability of the models and limited results provided by the software can make the simulation phase not suitable to evaluate the antenna placement. / Framtidens gruvor kommer att gynnas av sammankopplade, intelligenta transportsystem. Autonoma gruvfordon kommer att förbättra säkerhet och produktivitet, och samtidigt minska bränslekonsumtion. Därför är det nödvändigt för Scania att öka kunskapen om design av kommunikationssystem för fordon i hård gruvmiljö. Målet för detta projekt är att undersöka kraven för antennplacering hos ett framtida autonomt gruvfordon och att ge förslag på passande antenntyper och -positioner. Det elektromagnetiska simuleringsverktyget CST Microwave Studio används för att uppskatta påverkan från en förenklad fordonsgeometri på grundläggande antennstrålningsmönster. Utvalda antennkonfigurationer utvärderas genom undersökningar av dess strålningsmönster. För att kunna stråla ut tillräcklig effekt i området kring fordonet och garantera tillförlitlig kommunikation krävs centralt placerade runtstrålande antenner, eller alternativt en patchantenn till varje sida. Problemlösningsmetoden utvärderas också: Flexibiliteten simuleringsmetoden ger betonas, medan några relevanta begränsningar diskuteras. Hårdvarukrav, tillgängligheten av modeller och begränsade resultat från mjukvaran kan bidra till att göra simuleringen olämplig för att utvärdera antennplaceringen.

<p>Smart downlink scheduling can be used to reduce infrastructure-to-vehicle energy costs in delay tolerant roadside networks. In this thesis this type of scheduling is incorporated into ON/OFF roadside unit sleep activity, to further reduce infrastructure power consumption. To achieve significant power savings however, the OFF-to-ON sleep transitions may be very lengthy, and this overhead must be taken into account when performing the scheduling. The OFF/ON sleep transitions are incorporated into a lower bound on energy use for the constant bit rate air interface case. An online scheduling algorithm referred to as the Flow Graph Sleep Scheduler (FGS) is then introduced which makes locally optimum ON/OFF cycle decisions. This is done by computing energy estimates needed both with and without a new OFF/ON cycle. The energy calculation can be efficiently done using a novel minimum ow graph formulation. We also consider the fixed transmit power, variable bit rate, air interface case. As before, a lower bound on RSU energy use is computed by formulating and solving an integer program. Results from a variety of experiments show that the proposed scheduling algorithms perform well when compared to the energy lower bounds. The algorithms are especially attractive in situations where vehicle demands and arrival rates are such that the energy costs permit frequent ON/OFF cycling.</p> / Master of Science (MSc)