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Digital Telecommunications, 2009. ICDT '09. Fourth International Conference on

Date 20-25 July 2009

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Displaying Results 1 - 25 of 39
  • [Front cover]

    Publication Year: 2009, Page(s): C1
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  • [Title page i]

    Publication Year: 2009, Page(s): i
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  • [Title page iii]

    Publication Year: 2009, Page(s): iii
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  • [Copyright notice]

    Publication Year: 2009, Page(s): iv
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  • Table of contents

    Publication Year: 2009, Page(s):v - vii
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  • Preface

    Publication Year: 2009, Page(s):viii - ix
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  • Program Committee

    Publication Year: 2009, Page(s):x - xiii
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  • list-reviewer

    Publication Year: 2009, Page(s):xiv - xvi
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  • A Comparative Study of VoIP Standards with Asterisk

    Publication Year: 2009, Page(s):1 - 6
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (281 KB) | HTML iconHTML

    Since the apparition of Voice over IP (VoIP), many standards (mainly signaling protocols and codecs) have arisen with the aim of enabling voice calls through data networks. This paper describes a comparative study to evaluate the performance of a representative set of these standards when transmitting voice streams in a packet network. Asterisk PBX software is employed to define a testbed that all... View full abstract»

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  • Phase Lock Loop Used in Carrier Frequency and in Data Symbols

    Publication Year: 2009, Page(s):7 - 10
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (161 KB) | HTML iconHTML

    This work study the PLL (Phase Lock Loop) applied to systems of carrier frequency and data symbols. In each system, we consider four PLL types, namely the analog, hybrid, combinational and sequential.In the synchronizers for carrier frequency, the four PLL (Pll-cf) synchronizes directly with the input carrier.In the synchronizers for data symbols, the four PLL (f+Pll-ds) synchronizes with the data... View full abstract»

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  • Object-Oriented Framework for Development of Telephony Applications

    Publication Year: 2009, Page(s):11 - 14
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (148 KB) | HTML iconHTML

    This paper presents a prototype of a new application development framework for development of telephony services. Besides the first party call control, the framework provides support for third party call control, monitoring and presence service, which is based on publish/subscribe mechanism. The programming interface that framework provides maps successfully to mechanisms of SIP protocol and its e... View full abstract»

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  • Data Symbol Phase Synchronizers of Open Loop

    Publication Year: 2009, Page(s):15 - 18
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB) | HTML iconHTML

    In this work, we study the data symbol synchronizers of open loop. The recovered clock of this synchronizers hasnpsilat the capacity to follow the input changes. However, its simplicity allows operation at high data rates. We present four synchronizer types namely the tank circuit, the SAW (Surface Acoustic Wave) circuit, the monostable circuit and the astable circuit. The objective is to study th... View full abstract»

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  • Serial Concatenation of LDPC and Turbo Code for GPRS System under Different Fading Channels

    Publication Year: 2009, Page(s):19 - 23
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB) | HTML iconHTML

    In wireless communication systems, error control coding is necessary to provide reliable communications over fading channels. Turbo code is used practically in third generation due to good error correcting capability. However, it has error floor at high signal-to-noise ratio (SNR). Concatenation of another code as an outer code is an alternative to reduce turbo codepsilas error floor. In this pape... View full abstract»

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  • Study on Requirements for Service Interaction

    Publication Year: 2009, Page(s):24 - 29
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (270 KB) | HTML iconHTML

    The paper concerns problems for service orchestration in IP-based multimedia telecommunications. For operators that want to leverage the value of legacy systems and services, Service Capability Interaction Manager (SCIM) provides means of wrapping those systems and services so that they can be orchestrated alongside new services. SCIM functionality is not specified in details and dasialivepsila SC... View full abstract»

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  • Performance Analysis of Downlink Inter Cell Interference Coordination in the LTE-Advanced System

    Publication Year: 2009, Page(s):30 - 33
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (373 KB) | HTML iconHTML

    In the LTE-advanced system, cell edge user equipments (UEs) are affected by interference signals transmitted from other cells. For this reason, an inter cell interference coordination (ICIC) technique is required. The goal of ICIC is to improve cell coverage and increase cell edge throughput. In this paper, through a system level simulation, we show the user throughput of each multiple-input multi... View full abstract»

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  • Verification and Method Act Comparison of the Simulator and Emulator Result Based on NS-2

    Publication Year: 2009, Page(s):34 - 38
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (234 KB) | HTML iconHTML

    The existing simulation tools that execute performance analysis for handover algorithm in different network environments do not fully reflect the actual network environments. This is where the necessity of emulator whose operation environment is built on hardware comes in. The comparative analysis between emulation node which is a realtime scheduler including ping of NS-2 (Network Simulator versio... View full abstract»

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  • Carrier Wave Phase Synchronizers

    Publication Year: 2009, Page(s):39 - 42
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB) | HTML iconHTML

    This work study four carrier wave phase synchronizers (CWPS) or carrier wave phase lock loop (CWPLL).The VCO (voltage controlled oscillator) output of the phase synchronizer synchronizes directly with the input carrier wave.We consider four carrier synchronizers namely the analog, hybrid, combinational and sequential. The difference between them is in the phase detector.The objective is to study t... View full abstract»

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  • Narrowband Interference Suppression for IEEE UWB Channels

    Publication Year: 2009, Page(s):43 - 47
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (498 KB) | HTML iconHTML

    In this paper we put forward a scheme for suppressing narrowband interference by the use of adaptive narrowband filtering. We compare this method with other schemes for the suppression of complex narrowband interference in OFDM UWB systems, such as the frequency excision method and complex narrowband interference identification and cancelation algorithms. The study shows that the three schemes giv... View full abstract»

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  • Data Transmission for Major Sporting Events on MPEG-2

    Publication Year: 2009, Page(s):48 - 52
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (394 KB) | HTML iconHTML

    During mayor sporting events, such as the Olympic Games, in which a lot of stadiums are involved, each site will usually generate different types of video signal. The generation, distribution, integration and reproduction of data scores and results are very important for a good understanding of every sporting event. Data are sent securely across networks using any type of data protection and backu... View full abstract»

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  • Adaptive Multiplexing Based on E-model for Reducing Network Overhead in Voice over IP Security Ensuring Conversation Quality

    Publication Year: 2009, Page(s):53 - 58
    Cited by:  Papers (9)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1065 KB) | HTML iconHTML

    Obtaining VoIP security through the IPsec protocol increases packet size, thus substantially increasing the network overhead. One way of mitigating such a problem consists of multiplexing calls so that the transmission of redundant data is reduced. The performance of such technique is directly linked to the number of concurrent calls; however, in more constrained scenarios, the existence of severa... View full abstract»

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  • Skin Detection Using Contourlet-Based Texture Analysis

    Publication Year: 2009, Page(s):59 - 64
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (693 KB) | HTML iconHTML

    Detection of skin pixels in arbitrary images is addressed in this paper. We have combined texture and color information to segment skin regions. First, a pixel-based boosted skin detection method is used to locate skin pixels. To further improve the detect performance, skin region texture features are employed using the non-subsampled contourlet coefficients. For the candidate skin pixels, the set... View full abstract»

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  • Real-Time Estimation Method of the Number of Pedestrians in Video Sequences

    Publication Year: 2009, Page(s):65 - 70
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (3104 KB) | HTML iconHTML

    In a ubiquitous network society, information on mobile nodes such as pedestrians with cell phones in a target region is useful for network configuration, communication control, and so on. In this paper, we propose a novel method to estimate in real time the number of pedestrians in video sequences using a stationary camera. The proposed method extracts moving regions from video frame grabs using b... View full abstract»

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  • Internet TV Broadcast: What Next?

    Publication Year: 2009, Page(s):71 - 74
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (229 KB) | HTML iconHTML

    The use of broadcast TV channels is growing considerably so that the number of users (scalability) and the need to manage traffic (bandwidth) are challenges for network design and dimensioning. Broadcast and live channels show strict requirements to operate on a continuous basis in content distribution scenarios in terms of delay, huge demand of bandwidth and characterized by very dynamic variatio... View full abstract»

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  • Automatic Testing and Measurement of QoE in IPTV Using Image and Video Comparison

    Publication Year: 2009, Page(s):75 - 81
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (956 KB) | HTML iconHTML

    Orange Labs Spain, has developed a proof of concept aimed at exploring the possibility of automating the tests required by new evolutions of the IPTV service, and thus shortening the lifecycle and reducing the overall development costs. It's based on an automaton that interacts with the set-top box just by emulating a human being (or tester): sending IR remote control commands and analyzing the vi... View full abstract»

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  • Fast and Robust Multiframe Superresolution Using Inhibition Principle

    Publication Year: 2009, Page(s):82 - 87
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1278 KB) | HTML iconHTML

    An efficient super resolution (resolution enhancement) method for low resolution images is proposed in this paper. The algorithm is mainly based on a mathematical theorem (inhibition principle) for over determined scenario of superresolution. The proposed method aims at achieving a fast and computationally efficient resolution enhancement. Performance of the proposed method is compared to the conv... View full abstract»

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