Jinyong Jo

Synchronized one-to-many media streaming with adaptive playout control

A new inter-client synchronization framework for one-to-many (i.e., multicast) media streaming is proposed employing a server-client coordinated adaptive playout control. The proposed adaptive player controls the playback speed of audio and video by adopting the time-scale modification of audio. Based on the overall synchronization status as well as the buffer occupancy level, the playout speed of each client is manipulated within a perceptually tolerable range. Additionally, the server implicitly helps increasing the time available for retransmission while the clients perform an interactive error recovery mechanism with the assistance of playout control. By coordinating the playout speed of each client, the inter-client synchronization with respect to the target presentation time is smoothly achieved. RTCP-compatible signalling between the server and group-clients is performed, where the exchange of controlling message is restricted. The network-simulator based simulations show that the proposed framework can reduce the playout discontinuity without degrading the media quality, and thus mitigate the client heterogeneity.

Software-defined home networking devices for multi-home visual sharing

Existing home-networking protocols do not robustly incorporate universal connectivity among multiple homes, which leaves their use restricted to a single home. In addition, even in a single home network, new functional requirements ask for more diversified forms of networking control. This paper presents in-home consumer electronic devices that incorporate the emerging SDN (Software Defined Networking) paradigm. The proposed devices enable ondemand provisioning for protocol-agnostic home networking and thus provide a high degree of flexibility for intra-home networking as well as wider connectivity for inter-home networking. The feasibility of the prototype devices is verified by realizing a multi-home visual-sharing scenario and by supporting diverse future scenarios.

Evaluation on the performance of adaptive playout for the multicast streaming of stored media

A new inter-client synchronization framework employing a server-client coordinated adaptive playout and error control toward the multicast streaming of stored media is discussed in this paper. Based on the overall synchronization status as well as the buffer occupancy level, the playout speed of each client is manipulated within a perceptually tolerable range. By coordinating the playout speed of each client, the inter-client synchronization with respect to the target presentation time is smoothly achieved. The cumulative feedback for retransmission assisted by both playout speed manipulation at clients and implicit help of a streaming server is also conducted to increase the reliability. Simulation results demonstrate the performance of the proposed multicast streaming framework.

Interactive 3D HD video transport for e-science collaboration over UCLP-enabled GLORIAD lightpath

Emerging large-scale applications for e-science and Grid require end-to-end lightpaths that need to be dynamically provisioned with QoS (quality of service) guarantees. In this paper, an e-science collaboration is demonstrated as a part of iGRID2005, where an interactive 3D HD (high definition) video transport is realized over an inter-continental lambda integrated facility on 10 Gbps GLORIAD links. To realize real-time interactive (2-way) collaboration among scientific researchers, the 10 Gbps end-to-end user-controlled lightpath between Korea and USA is dynamically provided with very high network performance. Both uncompressed and stereoscopic HD videos are then exchanged between participating sites. Thus, we verify the potential of proposed e-science collaborations by discussing underlying lambda networking infrastructure, UCLP-enabled dynamic lightpath provisioning, HD video system setup and integration, and demonstration results.

Design and implementation of QoS measurement and network diagnosing framework for IP multicast in advanced collaborative environment

The access grid for collaborative environment exploits IP multicast. Although the IP multicast is quite a promising technology, it faces lots of challenges such as unreliable data transport and unstable network infrastructure. As a first step to achieve reliability and stability in IP multicast, it is essential to monitor and debug multicast networks. In this paper we introduce MMag, a user-oriented multicast monitoring tool for the access grid. The MMag provides both application and network level monitoring facilities to assess delivery statistics and to diagnose multicast problems. The implementation has been tested and will support access grid operators with a simple yet extensive view of multicast performance.

A NetFPGA-based IP Service Gateway for the Composition of Service Overlay Networks

Overlay network is a ready-to-use solution to enable new network functionality with existing Internet connectivity intact. This paper introduces a network service which helps users easily compose their own service overlay networks through software-defined networks. We look into the structure of service gateway which enables 1 Gbps packet processing on composed overlay networks. We also provide examples for the way of composing service overlay for support multicast applications. Experiment results carried over the KREONET (Korea Research Environment Open NETwork) show the forwarding performance of the service gateway.

Uncompressed high definition visual sharing system towards interactive networked collaboration

Recent growth in available network bandwidth envisions widespread use of broadband applications such as uncompressed Internet HDTV, a cutting-edge application technology for networked collaboration. In this paper, we introduce a cost-effective uncompressed HD visual sharing system and discuss its software architecture in depth. We also illustrate our experiences with the visual sharing system for interactive collaboration. Finally, experimental results will show how well it compensates for packet jitter to gear up media synchronization.

Optimizing System Performance for Uncompressed HDTV over 10-Gigabit Ethernet

Guaranteeing network bandwidth and system performance becomes important technical matters to make seamless delivery of bulky data at high speed. Tuning system and network parameters including jumbo frame, kernel buffer size, and interrupt coalescence determines end-to-end transmission throughput. Additionally, fine-tuning of the parameters alleviates workload on high-end systems. Until now, many studies have concentrated on how to increase transmission throughput but rarely discussed how to mitigate system workload. In this paper, we have investigated various tuning parameters, which positively affect networking and processing performance of uncompressed HDTV system.

Optimizing system performance for uncompressed HD over gigabit Ethernet: a case study

Uncompressed HD over IP is a broadband network application demanding high-end system performance. Finding bottleneck points and tuning them is essential for the service to achieve the performance requirements. In this paper, we massively investigate system parameters accelerating network and disk performance. Also, we introduce a software bottleneck and its effect to the system integrations

Integration of error recovery and adaptive playout for enhanced multicast media streaming

Multicast streaming has been extensively investigated to tackle the network bandwidth challenge. However, the ubiquitous deployment of IP multicast on the Internet is expected only after several years to come due to the manageability and scalability problems. We study a pragmatic solution to enhance the feasibility of multicast media streaming by focusing on an one-to-many streaming over the source specific multicast (SSM) service. In [1], we propose a synchronized multicast media streaming framework employing server-client coordinated adaptive playout. The adaptive playout mechanism controls the playout speed of audio and video by adopting the time-scale modification of audio. Based on the overall synchronization status as well as the buffer occupancy level, the playout speed of each client is manipulated within a perceptually tolerable range. In this work, we are extending the framework to incorporate the error recovery. Each client performs an interactive error recovery with the assistance of adaptive playout. RTCP-compatible signaling between the server and clients is performed, where the cumulative feedback for retransmission (to address the bandwidth restriction on the control messages) is assisted by the adaptive playout. The simulation results demonstrate several enhancements in terms of playout discontinuity and error recovery.