Hyunchul Joo

An Effective IPTV Channel Control Algorithm Considering Channel Zapping Time and Network Utilization

This paper presents a simple but effective IPTV channel control algorithm that keeps channel zapping time in the tolerable range with high network utilization. The proposed algorithm controls channel zapping time by adjusting the number of broadcasting channels that are located close to users over IP networks and the number of additional I-frames inserted into each channel, based on the users channel preference information. Finally, experimental results are provided to show the performance of the proposed algorithm.

An End-to-End Virtual Path Construction System for Stable Live Video Streaming over Heterogeneous Wireless Networks

In this paper, we propose an effective end-to-end virtual path construction system, which exploits path diversity over heterogeneous wireless networks. The goal of the proposed system is to provide a high quality live video streaming service over heterogeneous wireless networks. First, we propose a packetization-aware fountain code to integrate multiple physical paths efficiently and increase the fountain decoding probability over wireless packet switching networks. Second, we present a simple but effective physical path selection algorithm to maximize the effective video encoding rate while satisfying delay and fountain decoding failure rate constraints. The proposed system is fully implemented in software and examined over real WLAN and HSDPA networks.

An Effective Channel Control Algorithm for Integrated IPTV Services Over DOCSIS CATV Networks

In this paper, we present an effective IPTV channel control algorithm that guarantees a seamless channel change and provides a fast data communication service simultaneously via controlling the usage levels of uplink and downlink resources over DOCSIS CATV networks. The proposed algorithm treats the number of adjacent channels and the assigned grant interval as control variables to reduce the network delay part of channel zapping time and improve the quality-of-service of the uplink and downlink. Finally, the experimental results are provided to show the performance of the proposed algorithm.

A novel fountain code-based mobile IPTV multicast system architecture over WiMAX network

In this paper, we present a novel fountain code-based mobile IPTV multicast system architecture over WiMAX network. In the proposed system, the transmission algorithm at a base station determines the control parameters of a fountain-encoded IPTV multicast stream adaptively to the wireless link states of subscribers in order to provide a stable IPTV service with minimum resource usage on WiMAX network, and the channel grouping algorithm at a server makes near-optimal channel grouping based on channel selection preferences to pursue an effective tradeoff between the channel zapping time and the processing complexity of a subscriber. Finally, experimental results are provided to show the performance of the proposed system.

Wireless link state-aware H.264 MGS coding-based mobile IPTV system over WiMAX network

This paper presents a simple but effective architecture for the transmission of H.264 MGS coding-based IPTV stream over WiMAX network. The proposed system is implemented to provide more subscribers with an enhanced mobile IPTV service considering their wireless link states. In the proposed system, the base layer of the IPTV stream is transmitted with the sparsest modulation scheme and the lowest coding rate to provide IPTV service of minimum quality to as many subscribers as possible. And some parts of the enhancement layer are transmitted with the modulation scheme and the coding rate adaptive to wireless link states of subscribers. Basically, we pursue an efficient tradeoff between the number of subscribers that receive the enhancement layer stream and their IPTV service quality. Finally, experimental results are provided to show the performance of the proposed system.

QoE-aware mobile IPTV multicast system over WiMAX network

In this work, we present a QoE-aware mobile IPTV multicast system over WiMAX network. In the proposed system, the adaptive transmission algorithm at a base station determines the control parameters of a fountain-encoded IPTV multicast stream adaptively to the wireless link states of subscribers in order to provide a stable IPTV multicast service with minimum resource usage on WiMAX network, and the channel grouping algorithm at a server makes near-optimal channel grouping based on channel selection preferences in order to pursue an effective tradeoff between the channel zapping time and the processing complexity of a subscriber. Finally, experimental results are provided to show the performance of the proposed system.

Efficient Video Streaming System over Heterogeneous Wireless Networks

In this paper, we propose an efficient video streaming system over heterogeneous wireless networks. The proposed system modifies fountain code for the video streaming service and maximizes the target video encoding rate using multiple paths while satisfying delay and block recovery failure rate constraints of fountain code. Finally, the proposed system provides the seamless video streaming service of high quality to subscribers by dynamic adaptation of control parameters based on the states of each path over heterogeneous wireless networks.

A novel packet urgency metric-based cross-layer design for video streaming over multi-rate MANETs

This work proposes a novel packet urgency metric-based cross-layer design of packet scheduling and routing algorithms to effectively deliver video streaming data over mobile ad hoc networks based on IEEE 802.11 multi-rate service. First, the packet urgency, node urgency, and route urgency are defined on the basis of the residual time to the destination. Furthermore, the one-hop transmission delay of each packet is estimated using a Kalman filter. Next, the packet scheduling algorithm is proposed to minimize the node urgency without unnecessary packet drops based on both these urgency metrics and the estimated transmission delay. The proposed routing algorithm constructs a route to minimize the derivative of route urgency in order to maximize the number of packets delivered within the required end-to-end delay and distribute the entire traffic load. Finally, simulation results are provided to demonstrate the performance of the proposed cross-layer system.

Urgency-based packet scheduling and routing algorithms for delay-sensitive data over MANETs

This paper proposes urgency-based packet scheduling and routing algorithms to effectively deliver delay-sensitive data over a multi-hop mobile ad hoc networks supporting IEEE 802.11 multi-rate service. First, packet urgency, node urgency, and route urgency are defined on the basis of the end-to-end delay requirement. Based on these urgency metrics and the estimated transmission delay of each packet by Kalman filter, the proposed packet scheduling algorithm determines the transmission order and drop policy to minimize the node urgency without unnecessary packet drop, and the proposed routing algorithm establishes a route to minimize the derivative of route urgency in order to maximize the number of packets delivered within the required end-to-end delay. Finally, experimental results are presented to evaluate the performance of the proposed joint working algorithms.

Fountain code-based live video streaming system over heterogeneous wireless networks

In this work, we propose an effective live video streaming system, which exploits path diversity over heterogeneous wireless networks. Basically, fountain code is employed to efficiently integrate multiple paths and provide the error resilience for the live video streaming of high quality. In the proposed system, the path selection algorithm is designed to maximize the target video encoding rate while satisfying delay and decoding failure rate constraints of fountain codes. Finally, experimental results are provided to show the performance of the proposed system.