96 research outputs found

    An Efficient Metric for Physical-layer Jammer Detection in Internet of Things Networks

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    An active jammer could severely degrade the communication quality for wireless networks. Since all wireless nodes openly access the shared media, the harsh effects are exaggerated by retransmission attempts of affected devices. Fast and precise detection of the jammer is of vital importance for heterogeneous wireless environments such as the Internet of things (IoT). It could activate a series of corrective countermeasures to ensure the robust operation of the network. In this paper, we propose a local, straightforward, and numerical metric called the number of jammed slots (NJS), by which we can quickly detect the presence of a jammer and identify the jammed nodes at the software level in broadcast networks. NJS calculation is carried out by a central node which collects the MAC-layer statuses of all wireless nodes in a periodical fashion. Our simulation results indicate that NJS outperforms current detection methods in terms of accuracy and precision

    Managing the Mobility of a Mobile Sensor Network Using Network Dynamics

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    Formal modelling and analysis of denial of services attacks in wireless sensor networks

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    Wireless Sensor Networks (WSNs) have attracted considerable research attention in recent years because of the perceived potential benefits offered by self-organising, multi-hop networks consisting of low-cost and small wireless devices for monitoring or control applications in di±cult environments. WSN may be deployed in hostile or inaccessible environments and are often unattended. These conditions present many challenges in ensuring that WSNs work effectively and survive long enough to fulfil their functionalities. Securing a WSN against any malicious attack is a particular challenge. Due to the limited resources of nodes, traditional routing protocols are not appropriate in WSNs and innovative methods are used to route data from source nodes to sink nodes (base stations). To evaluate the routing protocols against DoS attacks, an innovative design method of combining formal modelling and computer simulations has been proposed. This research has shown that by using formal modelling hidden bugs (e.g. vulnerability to attacks) in routing protocols can be detected automatically. In addition, through a rigorous testing, a new routing protocol, RAEED (Robust formally Analysed protocol for wirEless sEnsor networks Deployment), was developed which is able to operate effectively in the presence of hello flood, rushing, wormhole, black hole, gray hole, sink hole, INA and jamming attacks. It has been proved formally and using computer simulation that the RAEED can pacify these DoS attacks. A second contribution of this thesis relates to the development of a framework to check the vulnerability of different routing protocols against Denial of Service(DoS) attacks. This has allowed us to evaluate formally some existing and known routing protocols against various DoS attacks iand these include TinyOS Beaconing, Authentic TinyOS using uTesla, Rumour Routing, LEACH, Direct Diffusion, INSENS, ARRIVE and ARAN protocols. This has resulted in the development of an innovative and simple defence technique with no additional hardware cost for deployment against wormhole and INA attacks. In the thesis, the detection of weaknesses in INSENS, Arrive and ARAN protocols was also addressed formally. Finally, an e±cient design methodology using a combination of formal modelling and simulation is propose to evaluate the performances of routing protocols against DoS attacks

    Mobile ad hoc networks for intelligent systems

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    Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. Mobile ad hoc networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. They do not rely on specialized routers for path discovery and traffic routing. Research on ad hoc networks has been extensively investigated in the past few years and related work has focused on many of the layers of the communications architecture. This research intends to investigate applications of MANET for intelligent systems, including intelligent transportation system (ITS), sensor network and mobile intelligent robot network, and propose some approaches to topology management, link layer multiple access and routing algorithms. Their performance is evaluated by theoretical analysis and off-the-shelf simulation tools. Most current research on ad hoc networks assumes the availability of IEEE 802.11. However, the RTS/CTS protocol of 802.11 still leads to packet collision which in turn decreases the network throughput and lifetime. For sensor networks, sensors are mostly battery operated. Hence, resolving packet collision may improve network lifetime by saving valuable power. Using space and network diversity combination, this work proposes a new packet separation approach to packet collision caused by masked nodes. Inter-vehicle communication is a key component of ITS and it is also called vehicular ad hoc network. VANET has many features different from regular MANETs in terms of mobility, network size and connectivity. Given rapid topology changes and network partitioning, this work studies how to organize the numerous vehicular nodes and establish message paths between any pair of vehicular nodes if they are not apart too far away. In urban areas, the inter-vehicle communication has different requirements and constraints than highway environments. The proposed position-based routing strategy for VANETs utilizes the traffic pattern in city environments. Packets are forwarded based on traffic lights timing sequence and the moving direction of relaying vehicles. A multicast protocol is also introduced to visualize the real time road traffic with customized scale. Only vehicles related to a source node\u27s planned trajectory will reply the query packet. The visualized real time traffic information therefore helps the driver make better decision in route planning when traffic congestion happens. Nowadays robots become more and more powerful and intelligent. They can take part in operations in a cooperative manner which makes distributed control necessary. Ad hoc robot communication network is still fresh field for researchers working on networking technology. This work investigates some key issues in robot ad hoc network and evaluate the challenges while establishing robot ad hoc networks

    Asioiden Internetin tietoturva: ratkaisuja, standardeja ja avoimia ongelmia

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    Internet of Things (IoT) extends the Internet to our everyday objects, which enables new kind of applications and services. These IoT applications face demanding technical challenges: the number of ‘things’ or objects can be very large, they can be very con-strained devices, and may need to operate on challenging and dynamic environments. However, the architecture of today’s Internet is based on many legacy protocols and technology that were not originally designed to support features like mobility or the huge and growing number of objects the Internet consists of today. Similarly, many security features of today’s Internet are additional layers built to fill up flaws in the un-derlying design. Fulfilling new technical requirements set by IoT applications requires efficient solutions designed for the IoT use from the ground up. Moreover, the imple-mentation of this new IoT technology requires interoperability and integration with tra-ditional Internet. Due to considerable technical challenges, the security is an often over-looked aspect in the emerging new IoT technology. This thesis surveys general security requirements for the entire field of IoT applica-tions. Out of the large amount of potential applications, this thesis focuses on two major IoT application fields: wireless sensor networks and vehicular ad-hoc networks. The thesis introduces example scenarios and presents major security challenges related to these areas. The common standards related to the areas are examined in the security perspective. The thesis also examines research work beyond the area of standardization in an attempt to find solutions to unanswered security challenges. The thesis aims to give an introduction to the security challenges in the IoT world and review the state of the security research through these two major IoT areas

    Reliability and Efficiency of Vehicular Network Applications

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    The DSRC/WAVE initiative is forecast to enable a plethora of applications, classified in two broad types of safety and non-safety applications. In the former type, the reliability performance is of tremendous prominence while, in the latter case, the efficiency of information dissemination is the key driving factor. For safety applications, we adopt a systematic approach to analytically investigate the reliability of the communication system in a symbiotic relationship with the host system comprising a vehicular traffic system and radio propagation environment. To this aim, the¬ interference factor is identified as the central element of the symbiotic relationship. Our approach to the investigation of interference and its impacts on the communication reliability departs from previous studies by the degree of realism incorporated in the host system model. In one dimension, realistic traffic models are developed to describe the vehicular traffic behaviour. In a second dimension, a realistic radio propagation model is employed to capture the unique signal propagation aspects of the host system. We address the case of non-safety applications by proposing a generic framework as a capstone architecture for the development of new applications and the efficiency evaluation of existing ones. This framework, while being independent from networking technology, enables accurate characterization of the various information dissemination tasks that a node performs in cooperation with others. As the central element of the framework, we propose a game theoretic model to describe the interaction of meeting nodes aiming to exchange information of mutual or social interests. An adaptive mechanism is designed to enable a mobile node to measure the social significance of various information topics, which is then used by the node to prioritize the forwarding of information objects
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