1,682 research outputs found

    A Driving Path Based Opportunistic Routing in Vehicular Ad Hoc Network

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    Vehicular Ad Hoc Networks is a promising technologythat can widely apply to monitor the physical world in urban areas.Efficient data delivery is important in these networks and optimalroute selection is vital to improve this factor. Vehicular mobility isa reflection of human social activity and human trajectories show ahigh degree of temporal and spatial regularity. Therefore, vehiculardriving paths are predictable in a large extent. A new opportunisticrouting protocol (DPOR) is proposed in this study that uses drivingpath predictability and vehicular distribution in its route selectionprocedure. This protocol is composed of two phases: intersectionand next hop selection phases. A utility function is calculated toselect the next intersection and a new mechanism is also proposedfor the next hop selection phase. Simulation results show thatDPOR achieves high delivery ratio and low end-to-end delay in thenetwork

    CALAR: Community Aware Location Assisted Routing Framework for Delay Tolerant Networks

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    Infrastructure less communication strategies havegreatly evolved and found its way to most of our real lifeapplications like sensor networks, terrestrial communications,military communications etc. The communication pattern for allthese scenarios being identical i.e. encounter basedcommunication,characteristics of each communication domainare distinct. Hence the protocols applied for each environmentshould be defined carefully by considering its owncommunication patterns. While designing a routing protocol themain aspects under consideration include delay, connectivity,cost etc. In case of applications having limited connectivity,concept of Delay tolerant network (DTN) is deployed, whichassists delivering messages even in partitioned networks withlimited connectivity by using store and forward architecture.Node properties like contact duration, inter contact duration,location, community, direction of movement, angle of contact etc.were used for designing different classes of routing protocols forDTN. This paper introduces a new protocol that exploits thefeatures of both community based as well as location basedrouting protocols to achieve higher data delivery ratio invehicular scenarios. Results obtained show that proposedalgorithms have much improved delivery ratio comparedtoexisting routing algorithms which use any one of the aboveproperty individually

    A routing defense mechanism using evolutionary game theory for Delay Tolerant Networks

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    Delay Tolerant Networks (DTNs) often suffer from intermittent disruption due to factors such as mobility and energy. Though lots of routing algorithms in DTNs have been proposed in the last few years, the routing security problems have not attracted enough attention. DTNs are still facing the threats from different kinds of routing attacks. In this paper, a general purpose defense mechanism is proposed against various routing attacks on DTNs. The defense mechanism is based on the routing path information acquired from the forwarded messages and the acknowledgment (ACK), and it is suitable for different routing schemes. Evolutionary game theory is applied with the defense mechanism to analyze and facilitate the strategy changes of the nodes in the networks. Simulation results show that the proposed evolutionary game theory based defense scheme can achieve high average delivery ratio, low network overhead and low average transmission delay in various routing attack scenarios. By introducing the game theory, the networks can avoid being attacked and provide normal transmission service. The networks can reach evolutionary strategy stable (ESS) under special conditions after evolution. The initial parameters will affect the convergence speed and the final ESS, but the initial ratio of the nodes choosing different strategies can only affect the game process

    A Neighborhood-Based Trust Protocol for Secure Collaborative Routing in Wireless Mobile D2D HetNets

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    Heterogeneous Device-to-Device mobile networks are characterised by frequent network disruption and unreliability of peers delivering messages to destinations. Trust-based protocols has been widely used to mitigate the security and performance problems in D2D networks. Despite several efforts made by previous researchers in the design of trust-based routing for efficient collaborative networks, there are fewer related studies that focus on the peers’ neighbourhood as a routing metrics’ element for a secure and efficient trust-based protocol. In this paper, we propose and validate a trust-based protocol that takes into account the similarity of peers’ neighbourhood coefficients to improve routing performance in mobile HetNets environments. The results of this study demonstrate that peers’ neighborhood connectivity in the network is a characteristic that can influence peers’ routing performance. Furthermore, our analysis shows that our proposed protocol only forwards the message to the companions with a higher probability of delivering the packets, thus improving the delivery ratio and minimizing latency and mitigating the problem of malicious peers ( using packet dropping strategy)

    Data storage solutions for the federation of sensor networks

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    In the near future, most of our everyday devices will be accessible via some network and uniquely identified for interconnection over the Internet. This new paradigm, called Internet of Things (IoT), is already starting to influence our society and is now driving developments in many areas. There will be thousands, or even millions, of constrained devices that will be connected using standard protocols, such as Constrained Application Protocol (CoAP), that have been developed under certain specifications appropriate for this type of devices. In addition, there will be a need to interconnect networks of constrained devices in a reliable and scalable way, and federations of sensor networks using the Internet as a medium will be formed. To make the federation of geographically distributed CoAP based sensor networks possible, a CoAP Usage for REsource LOcation And Discovery (RELOAD) was recently proposed. RELOAD is a peer-to-peer (P2P) protocol that ensures an abstract storage and messaging service to its clients, and it relies on a set of cooperating peers that form a P2P overlay network for this purpose. This protocol allows to define so-called Usages for applications to work on top of this overlay network. The CoAP Usage for RELOAD is, therefore, a way for CoAP based devices to store their resources in a distributed P2P overlay. Although CoAP Usage for RELOAD is an important step towards the federation of sensor networks, in the particular case of IoT there will be consistency and efficiency problems. This happens because the resources of CoAP devices/Things can be in multiple data objects stored at the overlay network, called P2P resources. Thus, Thing resource updates can end up being consuming, as multiple P2P resources will have to be modified. Mechanisms to ensure consistency become, therefore, necessary. This thesis contributes to advances in the federation of sensor networks by proposing mechanisms for RELOAD/CoAP architectures that will allow consistency to be ensured. An overlay network service, required for such mechanisms to operate, is also proposed.Num futuro próximo, a maioria dos nossos dispositivos do dia-a-dia estarão acessíveis através de uma rede e serão identificados de forma única para poderem interligar-se através da Internet. Este novo paradigma, conhecido hoje por Internet das Coisas (IoT), já está a começar a influenciar a nossa sociedade e está agora a impulsionar desenvolvimentos em inúmeras áreas. Teremos milhares, ou mesmo milhões, de dispositivos restritos que utilizarão protocolos padrão que foram desenvolvidos de forma a cumprir determinadas especificações associadas a este tipo de dispositivos, especificações essas que têm a ver com o facto destes dispositivos terem normalmente restrições de memória, pouca capacidade de processamento e muitos possuirem limitações energéticas. Surgirá ainda a necessidade de interligar, de forma fiável e escalonável, redes de dispositivos restritos.(…
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