Akimichi Ogawa

Design and implementation of DV stream over Internet

An Internet Protocol (IP) based high-quality real-time audio-visual (AV) communication tool has been developed. A digital video (DV) camcorder and VCR, being consumer market products, are adopted as the AV codec. The AV devices, which have an IEEE-1394 (Firewire) interface, are connected to the IP host with its interface. The original packet format is adopted by simply encapsulating the isochronous stream packet of the DV with UDP/IP. In the highest quality of communication, the system consumes over 35 Mbps of network bandwidth. The system can also change the bandwidth adaptively for end-to-end network conditions. The DV communication effort was performed using the APAN TransPAC link between the USA and Asia (Japan and Korea).

Enhancing the quality of DV over RTP with redundant audio transmission

In this paper, a scheme for reducing the packet loss probability of DV/RTP audio data is introduced. We have created a DV based broadcast quality video transportation tool, DVTS(Digital Video Transport System). Using DVTS, high quality video transportation over the Internet can be realized with low cost. However, DVTS does not have any error correction scheme. Moreover, it does not support reliable data transportation. Thus, a single packet loss can deteriorate the audio quality. In this paper, redundant transportation of DV audio data is intoduced. Using this redundant scheme, the DV audio will be robust. High quality audio can be realized in networks with packet loss.

Software compatibility and human interface for DV over IP

We created a high quality video transportation system for broadband networks, using DV (digital video) format. Our implementation was named DVTS (Digital Video Transport System). DVTS supports FreeBSD, NetBSD, Linux, MacOSX, and Windows operating systems. Each operating system has a different interface to interact with an application. For example, MacOS uses a GUI (graphical user interface) to allow end users to run applications with simple mouse and keyboard operation. We have ported DVTS to the MacOSX platform. MacOSX Aqua is an abstraction of a human interface based on a GUI. However, since the MacOSX implementation for the former DVTS is implemented using a CUI (character user interface), it does not assimilate with the MacOSX Aqua abstraction. Additionally, the video playback window for the DVTS receiver is designed with the QuickTime framework in our new system. Abstraction and implementation of DVTS for the Aqua interface is proposed. Due to this research, the usability of DVTS is enhanced.

Field-Trial of Dynamic SLA in Diffserv-Capable Network

As the Internet is undergoing substantial changes, there are many demands for the quality of the communication. Differentiated Services was standardized to meet such requirements. Currently, it is assumed that Diffserv is used under static Service Level Agreement (SLA). Under static SLA, the agreement between the service provider and the service subscribers are made as a result of negotiation between human agents. However, the service subscribers, especially individual users, may want dynamic SLA with which they can make their contract without human intervention and use the network resources immediately. Although many literatures addressed this point, operation of dynamic SLA under live network has not been applied. Moreover, only few experiments for dynamic SLA has been made. In this paper, we describe our field-trial with dynamic SLA and resource reservation system at the spring retreat of WIDE Project, including its network configuration and the results of trial. Through this experiment, we attempt to reveal that how users behave with dynamic SLA, and what mechanism such system needs.

Resource friendly platform requirements for portable computers using broadband applications

This research discloses the practical resource consumption of portable computers using broadband applications using IPv4 and IPv6. We tested with major broadband applications in a variety of operating system and network connections to verify the resource consumption. Resource consumption can be power consumption, bus utilization, device utilization, and processor utilization. Past application ignores its resource management which affects the efficiency of the usage. With collaboration and management of devices and its resource availability, effective use of resources can be performed resulting in the extension of battery time, lowering the heat, and economizing the bus utilization. Furthermore, this research introduces the sample application with the transport method for lazy resource adaptive streams using DVTS in IPv6, which effectively reduces the resource consumption. Implementation of resource management feature into a typical computer infrastructure may decrease the power consumption, and power conservation.