ITE Technical Report
Online ISSN : 2424-1970
Print ISSN : 1342-6893
ISSN-L : 1342-6893
26.13
Displaying 1-14 of 14 articles from this issue
  • Article type: Cover
    Pages Cover1-
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Article type: Index
    Pages Toc1-
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Yutaka ISHIBASHI, Takahiko HASEGAWA, Shuji TASAKA
    Article type: Article
    Session ID: NIM2002-92
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    This report assesses the quality of haptic media synchronization by experiment in the case where we operate an object in a 3-D virtual space by using haptic media in a distributed virtual environment. For haptic media synchronization control, we employ an enhanced version of the Virtual-Time Rendering (VTR) algorithm, which we previously proposed. The enhanced algorithm dynamically adjusts the buffering time according to the network load. In our experiment, we handle the enhanced algorithm and two other algorithms. The quality of haptic media synchronization has been assessed from the viewpoints of user-level QoS (Quality of Service) and application-level QoS. We also demonstrate the effectiveness of the enhanced algorithm.
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  • Toshiyasu KURASUGI, Kouji NISHI, Hiroyuki KAWAKAMI, Satoshi HASEGAWA
    Article type: Article
    Session ID: NIM2002-93
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    According to the expansion of broadband access network, the volume of streaming media contents, such as movies or music, is rapidly increasing in the Internet. Very high and sharply fluctuated bit rates are needed to deliver streaming contents. Statistical multiplexing gain must be predicted precisely to achieve required quality delivery cost effectively. Statistical multiplexing gain of Streaming media contents is said to be small. In this paper, we examine statistical gain of a RealMedia content and evaluated the bandwidth to deliver multiplexed RealMedia contents in required quality. Effective bandwidth is defined as bandwidth which is needed to deliver multiplexed contents in required quality. From simulation results, statistical gain of RealMedia Contents is very high if the low quality delivery (5% data loss) is permitted. If high quality delivery (under 1% data loss) is required, statistical multiplexing gain is smaller than the gain in low quality delivery. Traffic of Streaming media contents is said to be long-range dependent. Several analytical formulas to predict effective bandwidth are proposed. Those formulas are derived from analyses of long-range dependent models. In this paper, we check the accuracy of the Norros formula derived from FBM model analysis. Effective bandwidth calculated by the Norros formula is somewhat pessimistic. This result seems to represents that the bit rates of the RealMedia content seems to be more short-range dependent than FBM.
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  • Hirotsugu Okura, Masami Kato, Shuji Takasak
    Article type: Article
    Session ID: NIM2002-94
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    This report experimentally assesses the effect of segmentation mismatch on continuous media transmission by Bluetooth. The segmentation mismatch is mainly caused by the difference between RFCOMM Maximum Frame Size and baseband packet payload size. In the experiment, a media server transfers stored video and audio streams to a single terminal with point-to-point communication; we suppose no fading environment and add white noise by which interference from DSSS systems is modeled. The experiment showed that the effect of segmentation mismatch is large especially when the total bit rate of the two streams is near the channel transmission rate. We also observed that the media synchronization control is effective in compensating for the disturbance by the segmentation mismatch in noisy environments.
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  • Masahiro HAYASHI, Shuji TASAKA, Yutaka ISHIBASHI
    Article type: Article
    Session ID: NIM2002-95
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    This report presents experimental results of inter-destination synchronization control in an integrated wired and wireless network. The experimental system consists of interconnected wired and wireless networks; the former has three PCs, and the latter is a, wireless LAN with two base stations and two terminals. A server in the wired network multicasts audio and video streams to a terminal in the wired network and a wireless terminal. We exert inter-destination synchronization control between the two terminals using the synchronization maestro scheme, which the authors previously proposed. In this experiment, we measured inter-destination synchronization quality during handover and confirmed its effectiveness.
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  • Tatsuya YAMAZAKI, Kazuo HASUIKE, Kenichi MASE, Masakazu SENGOKU
    Article type: Article
    Session ID: NIM2002-96
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Distributing multimedia data to edge servers prevents concentration of access, so that end-users are provided high-quality multimedia services. The CCS (Communication Coordination Server) that we propose is a kind of edge server and provides QoS (Quality of Service) transform by a transcoding technique. We propose a new communication service coordination scheme for the CCS by content processing according to user's requirement or purpose.
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  • Keisuke Kushida, Jiro Katto
    Article type: Article
    Session ID: NIM2002-97
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Transmission scheme for wired networks is inefficient for wireless environment, and a wired / wireless gateway is required for Internet AV streaming. Packet loss protection is done at the wired side, random error concealment is done at the wireless side, and both of them are carried out at the wired / wireless gateway. In this paper, layered transmission scheme for Internet audio streaming using the wired / wireless gateway is focused. PCM and MP3 audio streams are divided into two classes. They are hierarchically encoded using UEP(Unequal Error Protection), and transferred to the gateway. At the gateway, error protection schemes are exchanged according to wired/ wireless characteristics.
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  • Satoshi KAMEI, Takumi KIMURA
    Article type: Article
    Session ID: NIM2002-98
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    P2P technology is paid attention as one of the next internet applications, as the user access networks have been broaden. To evaluate the impact of P2P traffic to networks, we construct traffic model of P2P traffic and evaluate them in a sample network. And, we charactarize the impact of P2P traffic to networks in comparison with that of web traffic.
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  • Yoshihiro Gotou, Shingo Ata, Masayuki Murata
    Article type: Article
    Session ID: NIM2002-99
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Peer-to-peer (P2P) is promising for a new service to provide a scalable, robust, and flexible communication on the Internet. However, in the current implementations of P2P services, their communication quality is still insufficient. One of critical issues is that their logical topology constructions do not incorporate the underlying physical network characteristics. In this paper, we propose a new approach to build a logical network, takeing account of the physical network characteristics. First, we investigate the essential parameter for 'good' logic network construction of P2P service by traffic measurements and show method to derive suitable parameters. We also consider the control traffic to identify its influence. We finally propose the peer selection technique based on physical network measurement, and verify it via a simulation and measurement evaluation.
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  • Hironao MORINO, Isamu ARIMOTO, Kenji HIKICHI, Yusuke KANEYASU, Kaoru S ...
    Article type: Article
    Session ID: NIM2002-100
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    Recently, development of haptic device is very hot topic. We investigate nerformance of the haptics communication against network impairments (delay, jitter, packet loss, etc.) Using dead reckoning algorithm, it is possible to reduce the data to be sent to the network. In this paper, we examine the influence of jitter and loss on sense of touch using dead reckoning algorithm.
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  • Tomohiro TERADA, Masayuki KANBARA, Naokazu YOKOYA
    Article type: Article
    Session ID: NIM2002-101
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
    This paper proposes an annotation overlay system for a vehicle in order to give user useful information of user's neighborhood. In a car navigation system which acqiuires the position of a user by global positioning system (GPS), the user can get information of user's neighborhood. However, since the system give the user information merged on a digital map, it is not easy for the user to given information with real objects. We propose an annotation overlay system using augmented reality which can merge a real and virutal worlds. The proposed system presents position-dependent information superimposed on image captured at a user's viewpoint by using a user's position acquired by GPS, velocity sensor and inertial sensor. The feasibility of the annotation overlay system has been successfully demonstrated with experiments.
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  • Article type: Appendix
    Pages App1-
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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  • Article type: Appendix
    Pages App2-
    Published: February 08, 2002
    Released on J-STAGE: June 23, 2017
    CONFERENCE PROCEEDINGS FREE ACCESS
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