54,148 research outputs found

    Integrated Social and Quality of Service Trust Management of Mobile Groups in Ad Hoc Networks

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    Abstract—We propose to combine social trust derived from social networks with quality-of-service (QoS) trust derived from communication networks to obtain a composite trust metric as a basis for evaluating trust of mobile nodes in mobile ad hoc network (MANET) environments. We develop a novel modelbased approach to identify the best protocol setting under which trust bias is minimized, that is, the peer-to-peer subjective trust as a result of executing our distributed trust management protocol is close to ground truth status over a wide range of operational and environment conditions with high resiliency to malicious attacks and misbehaving nodes. Keywords—trust management; mobile ad hoc networks; QoS trust; social trust; trust bias minimization. I

    Profile-Based Ad Hoc Social Networking Using Wi-Fi Direct on the Top of Android

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    Ad-hoc Social Networks have become popular to support novel applications related to location-based mobile services that are of great importance to users and businesses. Unlike traditional social services using a centralized server to fetch location, ad-hoc social network services support infrastructure less real-time social networking. It allows users to collaborate and share views anytime anywhere. However, current ad-hoc social network applications are either not available without rooting the mobile phones or don't filter the nearby users based on common interests without a centralized server. This paper presents an architecture and implementation of social networks on commercially available mobile devices that allow broadcasting name and a limited number of keywords representing users' interests without any connection in a nearby region to facilitate matching of interests. The broadcasting region creates a digital aura and is limited by WiFi region that is around 200 meters. The application connects users to form a group based on their profile or interests using peer-to-peer communication mode without using any centralized networking or profile matching infrastructure. The peer-to-peer group can be used for private communication when the network is not available

    Consistency Management Among Replicas in Peer-to-Peer Mobile Ad Hoc Networks

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    Recent advances in wireless communication along with peer-to-peer (P2P) paradigm have led to increasing interest in P2P mobile ad hoc networks. In this paper, we assume an environment where each mobile peer accesses data items held by other peers which are connected by a mobile ad hoc network. Since peers\u27 mobility causes frequent network partitions, replicas of a data item may be inconsistent due to write operations performed by mobile peers. In such an environment, the global consistency of data items is not desirable by many applications. Thus, new consistency maintenance based on local conditions such as location and time need to be investigated. This paper attempts to classify different consistency levels according to requirements from applications and provides protocols to realize them. We report simulation results to investigate the characteristics of these consistency protocols in a P2P wireless ad hoc network environment and their relationship with the quorum sizes

    Internet Access and QoS in Ad Hoc Networks

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    It is likely that the increased popularity of wireless local area networks (WLANs) together with the continuous technological advances in wireless communication, also increase the interest for ad hoc networks. An ad hoc network is a wireless, autonomous, infrastructure-less network composed of stations that communicate with each other directly in a peer-to-peer fashion. When discussing mobile ad hoc networks (MANETs), we often refer to an ad hoc network where the stations cooperate in forwarding packets on behalf of each other to allow communication beyond their transmission range over multi-hop paths. In order to realize the practical benefits of ad hoc networks, two challenges (among others) need to be considered: distributed quality of service (QoS) guarantees and multi-hop Internet access. This thesis presents conceivable solutions to both of these problems. The first two papers focus on the network layer and consider the provisioning of Internet access to ad hoc networks whereas the last two papers focus on the data link layer and investigate the provisioning of QoS to ad hoc networks. The first paper studies the interconnection between a MANET and the Internet. In addition, it evaluates three approaches for gateway discovery, which can be initiated by the gateway (proactive method), by the mobile station (reactive method) or by mixing these two approaches (hybrid method). The second paper also studies Internet access for MANETs, but with focus on micro mobility, i.e. mobile stations moving from one gateway to another. In particular, it evaluates a solution that allows mobile stations to access the Internet and roam from gateway to gateway. The third paper, gives an overview of the medium access mechanisms in IEEE 802.11 and their QoS limitations. Moreover, it proposes an enhancement to the contention-free medium access mechanism of IEEE 802.11e to provide QoS guarantees in WLANs operating in ad hoc network configuration. The fourth paper continues the work from the third paper by enhancing the scheme and dealing with the problems that occur due to hidden stations. Furthermore, it discusses how to deal with the problems that occur when moving from single-hop ad hoc networks (i.e. WLANs in ad hoc network configuration) to multi-hop ad hoc networks

    FRAMEWORK FOR AD HOC NETWORK COMMUNICATION IN MULTI-ROBOT SYSTEMS

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    Assume a team of mobile robots operating in environments where no communication infrastructure like routers or access points is available. The robots have to create a mobile ad hoc network, in that case, it provides communication on peer-to-peer basis. The paper gives an overview of existing solutions how to route messages in such ad hoc networks between robots that are not directly connected and introduces a design of a software framework for realization of such communication. Feasibility of the proposed framework is shown on the example of distributed multi-robot exploration of an a priori unknown environment. Testing of developed functionality in an exploration scenario is based on results of several experiments with various input conditions of the exploration process and various sizes of a team and is described herein

    Context Aware Service Oriented Computing in Mobile Ad Hoc Networks

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    These days we witness a major shift towards small, mobile devices, capable of wireless communication. Their communication capabilities enable them to form mobile ad hoc networks and share resources and capabilities. Service Oriented Computing (SOC) is a new emerging paradigm for distributed computing that has evolved from object-oriented and component-oriented computing to enable applications distributed within and across organizational boundaries. Services are autonomous computational elements that can be described, published, discovered, and orchestrated for the purpose of developing applications. The application of the SOC model to mobile devices provides a loosely coupled model for distributed processing in a resource-poor and highly dynamic environment. Cooperation in a mobile ad hoc environment depends on the fundamental capability of hosts to communicate with each other. Peer-to-peer interactions among hosts within communication range allow such interactions but limit the scope of interactions to a local region. Routing algorithms for mobile ad hoc networks extend the scope of interactions to cover all hosts transitively connected over multi-hop routes. Additional contextual information, e.g., knowledge about the movement of hosts in physical space, can help extend the boundaries of interactions beyond the limits of an island of connectivity. To help separate concerns specific to different layers, a coordination model between the routing layer and the SOC layer provides abstractions that mask the details characteristic to the network layer from the distributed computing semantics above. This thesis explores some of the opportunities and challenges raised by applying the SOC paradigm to mobile computing in ad hoc networks. It investigates the implications of disconnections on service advertising and discovery mechanisms. It addresses issues related to code migration in addition to physical host movement. It also investigates some of the security concerns in ad hoc networking service provision. It presents a novel routing algorithm for mobile ad hoc networks and a novel coordination model that addresses space and time explicitly
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