1,223 research outputs found

    Increased Persistence of Wi-Fi Direct Networks for Smartphone-based Collision Avoidance

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    Inter-vehicular communication is a promising technology to improve road safety. Inter-vehicular communication over a wireless medium can be used to exchange important information such as the speed, location, and headings of a vehicle with nearby vehicles. Using this information, it is possible to calculate if a collision is imminent and warn the driver to take action. Wi-Fi can also be used to share this information, however it requires an access point hardware to facilitate communication. Wi-Fi Direct enabled devices can share information without a hardware access point. Wi-Fi Direct provides peer to peer communication by employing a software defined access point embedded within the system. Wi-Fi Direct is a technology that is present on many smart phones, eliminating the need for dedicated access point hardware. In collision avoidance application, Wi-Fi Direct maybe used to exchange safety-related information between vehicles. Collision avoidance systems developed using smartphones can also be extended to protecting pedestrians carrying a smartphone and in this role they could be a long-term solution for certain vulnerable road user collision scenarios. Smartphones with Wi-Fi Direct capability could provide a path to early, low-cost implementation of inter-vehicle communication for collision avoidance. However, there are many limitations to such a system that are addressed in this thesis. Wi-Fi Direct functions by creating groups. One of the nodes in the group is elected as the group owner that acts as an access point and manages the communication between the nodes within the group. If the group owner moves out of range, reforming the group is a lengthy process. This thesis proposes a new method for nomination of the group owner to reduce the likelihood that the group owner will move out of range. This thesis introduces the concept of nominating a Backup Group Owner that can quickly replace the group owner if the group owner shuts down or moves out of range of the group. An orderly handoff from the group owner to the Backup Group Owner can prevent loss of communication among nodes. An analytical study of the amount of time saved by adopting the proposed method of electing the BGO is presented

    Personal area technologies for internetworked services

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    Implementation and experimental evaluation of Cooperative Awareness Basic Service for V2X Communications

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    A key aspect of Vehicle-to-Everything (V2X) communication is the concept of cooperative awareness, wherein the periodic exchange of status information allows vehicles to become aware of their surroundings for increased traffic safety and efficiency. This project aimed to implement the Cooperative Awareness (CA) basic service through the development of a low-cost, open-source On-board Unit (OBU)/Roadside Unit (RSU) that periodically broadcasts Cooperative Awareness Messages (CAM) using the 5.9 GHz band. Its proper operation and interoperability were verified by testing it with a commercial V2X device. This project also aimed to evaluate the effectiveness of the CA basic service through the development of an IEEE 802.11p-based V2X system simulator. The simulations were executed with varying vehicle traffic load (by changing the vehicle speed and the number of lanes) and CAM transmit frequency. The performance was then assessed by analyzing the Packet Reception Ratio (PRR), position error and Neighborhood Awareness Ratio (NAR) metrics. The presence of more vehicles in the slow speed and high lane count scenarios caused higher packet losses due to increased interference and collision probability, leading to low PRR and NAR values. Despite losing more CAMs, the slow speed scenarios had lower position errors since the displacement of vehicles was small. When the CAM transmit frequency was increased, the PRR decreased due to packet collisions. However, the position error was kept low as it benefited from the more frequent CAM transmissions and local database updates. Increasing the transmit frequency also increased the NAR, at least until a certain frequency threshold, beyond which the NAR started to worsen due to the dominant effect of interference in high message traffic situations

    COLOMBO Deliverable 1.1: Scenario Specifications and Required Modifications to Simulation Tools

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    While targeting on supporting descriptions of scenarios and extensions to the simulation suite, the document additionally delivers a complete overview of the evaluation procedures to use in COLOMBO. Starting with an overview of the evaluation process, based on work done in the FESTA project, the document includes definitions of the performance indicators to use. These were originally produced by the iTETRIS project (by consortium partners of COLOMBO, mainly) and was extended within COLOMBO by performance indicators that describe the behaviour of inter-vehicle communication. To put the work on a scientific ground, a performed comparison of 40 scientific simulation studies is given, that shows that no standard scenarios and metrics exist. Additionally the document lists feature extensions which shall be implemented into the simulation tools within the COLOMBO project. Applicable software and data yielding to the scenarios were provided to the COLOMBO partners. As targeted, the document lists the scenarios made available within COLOMBO, distinguishing synthetic and real-world scenarios. Overall, seven scenarios based on real-world data were made available. Additionally, a tool that allows generating a large variety of synthetic scenarios is presented. The document ends with an extension (against the one given in D5.1) of requirements put on the simulations suite

    A Comprehensive Survey on Networking over TV White Spaces

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    The 2008 Federal Communication Commission (FCC) ruling in the United States opened up new opportunities for unlicensed operation in the TV white space spectrum. Networking protocols over the TV white spaces promise to subdue the shortcomings of existing short-range multi-hop wireless architectures and protocols by offering more availability, wider bandwidth, and longer-range communication. The TV white space protocols are the enabling technologies for sensing and monitoring, Internet-of-Things (IoT), wireless broadband access, real-time, smart and connected community, and smart utility applications. In this paper, we perform a retrospective review of the protocols that have been built over the last decade and also the new challenges and the directions for future work. To the best of our knowledge, this is the first comprehensive survey to present and compare existing networking protocols over the TV white spaces.Comment: 19 page

    Integrating Haptic Feedback into Mobile Location Based Services

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    Haptics is a feedback technology that takes advantage of the human sense of touch by applying forces, vibrations, and/or motions to a haptic-enabled device such as a mobile phone. Historically, human-computer interaction has been visual - text and images on the screen. Haptic feedback can be an important additional method especially in Mobile Location Based Services such as knowledge discovery, pedestrian navigation and notification systems. A knowledge discovery system called the Haptic GeoWand is a low interaction system that allows users to query geo-tagged data around them by using a point-and-scan technique with their mobile device. Haptic Pedestrian is a navigation system for walkers. Four prototypes have been developed classified according to the user’s guidance requirements, the user type (based on spatial skills), and overall system complexity. Haptic Transit is a notification system that provides spatial information to the users of public transport. In all these systems, haptic feedback is used to convey information about location, orientation, density and distance by use of the vibration alarm with varying frequencies and patterns to help understand the physical environment. Trials elicited positive responses from the users who see benefit in being provided with a “heads up” approach to mobile navigation. Results from a memory recall test show that the users of haptic feedback for navigation had better memory recall of the region traversed than the users of landmark images. Haptics integrated into a multi-modal navigation system provides more usable, less distracting but more effective interaction than conventional systems. Enhancements to the current work could include integration of contextual information, detailed large-scale user trials and the exploration of using haptics within confined indoor spaces
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