269,081 research outputs found

    Hybrid mobile positioning managment framework based on radio communication and global positioning approaches

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    Mobile devices location systems for remote objects (vehicle, person, commodity, etc.), such as RTLS (Real Time Location System) in general and AVL (Automatic Vehicle Location) particularly for vehicles and persons, are increasingly used today by several enterprises. Indeed, this facilitates the management of personal, products, increases productivity, and so on. These systems use positioning devices such as GPS and communication devices to send remote location data. The first constraint of GPS is that it does not provide a precise position at any time. The extensions of GPS such as WAAS systems and A-GPS, that improve the precision, have also other constraints (availability and cost). The second constraint comes when sending remote location data. Often, the communication devices used for this purpose are GSM modules that send data on the GSM network. The use of GSM network is expensive to send data periodically. To overcome these drawbacks (improve precision and send data with minimum cost), we propose a framework on hybrid mobile devices management system to create a reliable and optimal location system by: i) coupling the radio devices at low integration cost with GPS devices, ii) allowing different mobile objects to cooperate and deliver the positioning data to the remote server

    K-Trek: A Peer-to-Peer Approach To Distribute Knowledge In Large Environments

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    In this paper, we explore an architecture, called K-Trek, that enables mobile users to travel across knowledge distributed over a large geographical area (ranging from large public buildings to a national park). Our aim is providing, dis-tributing, and enriching the environment with location-sensitive information for use by agents on board of mobile and static devices. Local interactions among K-Trek devices and the distribution of information in the larger environment adopt some typical peer-to-peer patterns and techniques. We introduce the architecture, discuss some of its potential knowledge management applications, and present a few experimental results obtained with simulation

    Impact of Location Spoofing Attacks on Performance Prediction in Mobile Networks

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    Performance prediction in wireless mobile networks is essential for diverse purposes in network management and operation. Particularly, the position of mobile devices is crucial to estimating the performance in the mobile communication setting. With its importance, this paper investigates mobile communication performance based on the coordinate information of mobile devices. We analyze a recent 5G data collection and examine the feasibility of location-based performance prediction. As location information is key to performance prediction, the basic assumption of making a relevant prediction is the correctness of the coordinate information of devices given. With its criticality, this paper also investigates the impact of position falsification on the ML-based performance predictor, which reveals the significant degradation of the prediction performance under such attacks, suggesting the need for effective defense mechanisms against location spoofing threats

    Seamless SIP multimedia session transfer on IPv6 network via device switching

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    Due to significant popularity of Location-based Services and Multimedia communication over mobile devices, there are many researches has been conducted to extend the features of location tracking and make it cost-effective to users. It becomes necessary for the users to have seamless communication with automated switching of software applications. This paper focuses on the performance of indoor location tracking system on IPv6 Network Island with multiple real time applications that has location assisted transfer for mobile users. RSSI (Received Signal Strength Indicator) mechanism has been used to locate the moving nodes. The developed location tracking server is having dynamic and centralized MySQL database management system. SIP (Session Initial Protocols) user agent has been used to deploy intercommunicating of multimedia data for instance; video and audio conference, text messaging among the moving nodes and user can transfer the seamlessly transfer the session to their nearest mobile node which will be determined by the Location Server. This paper is going to discuss about the seamless performance of SIP during the session transference. The developed project is cost-effective and precisely conducive for the industries or any indoor organization. The prototype of the project has been successfully developed and has been tested as well. The results show the seamless connectivity of the multimedia application during device switching

    Amorphous Placement and Informed Diffusion for Timely Monitoring by Autonomous, Resource-Constrained, Mobile Sensors

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    Personal communication devices are increasingly equipped with sensors for passive monitoring of encounters and surroundings. We envision the emergence of services that enable a community of mobile users carrying such resource-limited devices to query such information at remote locations in the field in which they collectively roam. One approach to implement such a service is directed placement and retrieval (DPR), whereby readings/queries about a specific location are routed to a node responsible for that location. In a mobile, potentially sparse setting, where end-to-end paths are unavailable, DPR is not an attractive solution as it would require the use of delay-tolerant (flooding-based store-carry-forward) routing of both readings and queries, which is inappropriate for applications with data freshness constraints, and which is incompatible with stringent device power/memory constraints. Alternatively, we propose the use of amorphous placement and retrieval (APR), in which routing and field monitoring are integrated through the use of a cache management scheme coupled with an informed exchange of cached samples to diffuse sensory data throughout the network, in such a way that a query answer is likely to be found close to the query origin. We argue that knowledge of the distribution of query targets could be used effectively by an informed cache management policy to maximize the utility of collective storage of all devices. Using a simple analytical model, we show that the use of informed cache management is particularly important when the mobility model results in a non-uniform distribution of users over the field. We present results from extensive simulations which show that in sparsely-connected networks, APR is more cost-effective than DPR, that it provides extra resilience to node failure and packet losses, and that its use of informed cache management yields superior performance
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