605 research outputs found
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂşblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
Final report on the evaluation of RRM/CRRM algorithms
Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin
Traffic agents for improving QoS in mixed infrastructure and ad hoc modes wireless LAN
As an important complement to infrastructured wireless networks, mobile ad hoc networks (MANET) are more flexible in providing wireless access services, but more difficult in meeting different quality of service (QoS) requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks (WLAN), which can offer high data-rate wireless multimedia services to the mobile stations (MSs) in a limited geographical area. For those out-of-coverage MSs, how to effectively connect them to the access point (AP) and provide QoS support is a challenging issue. By mixing the infrastructure and the ad hoc modes in WLAN, we propose in this paper a new coverage improvement scheme that can identify suitable idle MSs in good service zones as traffic agents (TAs) to relay traffic from those out-of-coverage MSs to the AP. The service coverage area of WLAN is then expanded. The QoS requirements (e.g., bandwidth) of those MSs are considered in the selection process of corresponding TAs. Mathematical analysis, verified by computer simulations, shows that the proposed TA scheme can effectively reduce blocking probability when traffic load is light
A Coordination Model and Framework for Developing Distributed Mobile Applications
How to coordinate multiple devices to work together as a single application is one of the most important
challenges for building a distributed mobile application. Mobile devices play important roles in daily life
and resolving this challenge is vital. Many coordination models have already been developed to support the
implementation of parallel applications, and LIME (Linda In a Mobile Environment) is the most popular
member. This thesis evaluates and analyzes the advantages and disadvantages of the LIME, and its predecessor
Linda coordination model. This thesis proposes a new coordination model that focuses on overcoming
the drawbacks of LIME and Linda. The new coordination model leverages the features of consistent hashing
in order to obtain better coordination performance. Additionally, this new coordination model utilizes the
idea of replica mechanism to guarantee data integrity. A cross-platform coordination framework, based on
the new coordination model, is presented by this thesis in order to facilitate and simplify the development
of distributed mobile applications. This framework aims to be robust and high-performance, supporting
not only powerful devices such as smartphones but also constrained devices, which includes IoT sensors.
The framework utilizes many advanced concepts and technologies such as CoAP protocol, P2P networking,
Wi-Fi Direct, and Bluetooth Low Energy to achieve the goals of high-performance and fault-tolerance. Six
experiments have been done to test the coordination model and framework from di erent aspects including
bandwidth, throughput, packages per second, hit rate, and data distribution. Results of the experiments
demonstrate that the proposed coordination model and framework meet the requirements of high-performance
and fault-tolerance
SISTEMI PER LA MOBILITĂ€ DEGLI UTENTI E DEGLI APPLICATIVI IN RETI WIRED E WIRELESS
The words mobility and network are found together in many contexts. The issue alone of modeling geographical user mobility in wireless networks has countless applications. Depending on one’s background, the concept is investigated with very different tools and aims.
Moreover, the last decade saw also a growing interest in code mobility, i.e. the possibility for soft-ware applications (or parts thereof) to migrate and keeps working in different devices and environ-ments. A notable real-life and successful application is distributed computing, which under certain hypothesis can void the need of expensive supercomputers. The general rationale is splitting a very demanding computing task into a large number of independent sub-problems, each addressable by limited-power machines, weakly connected (typically through the Internet, the quintessence of a wired network).
Following this lines of thought, we organized this thesis in two distinct and independent parts:
Part I
It deals with audio fingerprinting, and a special emphasis is put on the application of broadcast mon-itoring and on the implementation aspects. Although the problem is tackled from many sides, one of the most prominent difficulties is the high computing power required for the task. We thus devised and operated a distributed-computing solution, which is described in detail. Tests were conducted on the computing cluster available at the Department of Engineering of the University of Ferrara.
Part II
It focuses instead on wireless networks. Even if the approach is quite general, the stress is on WiFi networks. More specifically, we tried to evaluate how mobile-users’ experience can be improved. Two tools are considered. In the first place, we wrote a packet-level simulator and used it to esti-mate the impact of pricing strategies in allocating the bandwidth resource, finding out the need for such solutions. Secondly, we developed a high-level simulator that strongly advises to deepen the topic of user cooperation for the selection of the “best” point of access, when many are available. We also propose one such policy
Supply-Push or Demand-Pull as Driver for Local Access Provisioning? - Initial Findings from Interviews with Market Actors
This paper analyzes push-pull initiatives of technological development by studying the concept of Novel Access Provisioning of new wireless Internet access to existing backbone infrastructure. The Novel Access Provisioning project is conducted within the Swedish techno-economic research project with participants from the Royal Institute of Technology (KTH), Stockholm School of Economics (SSE) and the Swedish Telecom Agency (PTS). This paper reports on the results from a series of interviews during the fall of 2005 with main representatives from within the Telecom Industry and outside in the Nordic market having an interest in the development and use of mobile services. The aim of the paper is to increase the understanding for why some innovations have a rapid rate of adoption while others are deployed more slowly
VANET Applications: Hot Use Cases
Current challenges of car manufacturers are to make roads safe, to achieve
free flowing traffic with few congestions, and to reduce pollution by an
effective fuel use. To reach these goals, many improvements are performed
in-car, but more and more approaches rely on connected cars with communication
capabilities between cars, with an infrastructure, or with IoT devices.
Monitoring and coordinating vehicles allow then to compute intelligent ways of
transportation. Connected cars have introduced a new way of thinking cars - not
only as a mean for a driver to go from A to B, but as smart cars - a user
extension like the smartphone today. In this report, we introduce concepts and
specific vocabulary in order to classify current innovations or ideas on the
emerging topic of smart car. We present a graphical categorization showing this
evolution in function of the societal evolution. Different perspectives are
adopted: a vehicle-centric view, a vehicle-network view, and a user-centric
view; described by simple and complex use-cases and illustrated by a list of
emerging and current projects from the academic and industrial worlds. We
identified an empty space in innovation between the user and his car:
paradoxically even if they are both in interaction, they are separated through
different application uses. Future challenge is to interlace social concerns of
the user within an intelligent and efficient driving
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