Hwangjun Song

An Energy-Efficient HTTP Adaptive Video Streaming With Networking Cost Constraint Over Heterogeneous Wireless Networks

This paper presents a seamless high-quality HTTP adaptive streaming algorithm that considers wireless network conditions and the energy consumption of a mobile device with networking cost constraints over heterogeneous wireless networks. In the proposed algorithm, the requested video segments are concurrently delivered through multiple wireless networks to overcome the limitations of a single network. The segment quality level, number of requested segments, network inactive interval, and amount of requested data through each wireless network are determined adaptively in order to provide a seamless high-quality video with low energy consumption and networking cost constraints at the mobile device. The proposed algorithm is fully implemented in an Android-based mobile device and tested in an actual wireless network environment.

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.

QoS-aware routing and power control algorithm for multimedia service over multi-hop mobile ad hoc network

This paper presents a QoS (quality of service) aware routing and power control algorithm consuming low transmission power for multimedia service over mobile ad hoc network. Generally, multimedia services need stringent QoS over the network. However, it is not easy to guarantee the QoS over mobile ad hoc network since its network resources are very limited and time-varying. Furthermore, only a limited amount of power is available at mobile nodes, which makes the problem more challenging. We propose an effective routing and power control algorithm for multimedia services that satisfies end-to-end delay constraint with low transmission power consumption. The proposed algorithm supports the required bandwidth by controlling each link channel quality over route in a tolerable range. In addition, a simple but effective route maintenance mechanism is implemented to avoid link failures that may significantly degrade streaming video quality. Finally, performance comparison with existing algorithms is presented in respect to traditional routing performance metrics, and an achievable video quality comparison is provided to demonstrate the superiority of the proposed algorithm for multimedia services over mobile ad hoc network. Copyright

Overlay Tree Construction Algorithm for Synchronized Realtime Media Multicast Service over the Best-Effort Service Internet

This paper presents an overlay multicast tree construction algorithm for synchronized realtime media multicast service over Internet which traditionally supports only best-effort service. The proposed tree construction algorithm is implemented to reduce not only the average delay of group members in order to support realtime media service, but also the delay variance among group members to provide an effective synchronized service. Basically, the orthogonal genetic algorithm is employed to obtain the near optimal tree among clusters with low computational complexity since the given problem is NP-complete. In addition, a dynamic tree maintenance process is proposed to effectively update the tree when members change due to leave or join. Finally, we describe experiments that show the superior performance of the proposed algorithm.

An effective cross-layer designed packet scheduling, call admission control, and handover system for video streaming services over LTE network

We define QoE metrics based on the amount of buffered video frames.We propose cross-layer designed PS, CAC, and HO system tightly coupled on QoE state.The PS algorithm considers QoE states and wireless link states of UEs.The CAC algorithm estimates cell availability at the next call arriving time.The HO algorithm attains well-balanced traffic load among cells based on QoE state. This paper presents an effective cross-layer designed packet scheduling, call admission control, and handover system to provide a seamless video streaming services over LTE network. The proposed packet scheduling algorithm allocates wireless network resources to admitted UEs while considering QoE states and wireless link states of UEs simultaneously. The proposed call admission control algorithm estimates the cell availability at the next call arriving time based on the current QoE states of UEs to determine the admission of a new UE. The proposed handover algorithm determines the appropriate handover trigger timing to keep a balance of the QoE states among immediately adjacent cells based on both the cell availability and wireless link states. Finally, simulations are conducted to evaluate the performance of the proposed system. Results indicate that the proposed cross-layer designed system improves the QoE states of all admitted UEs and overall network utilization better than other existing methods.

Entire network load-aware cooperative routing algorithm for video streaming over mobile ad hoc networks

In this paper, we present an entire network load-aware cooperative routing algorithm based on IEEE 802.11 multi-rate for video streaming over mobile ad hoc networks. The proposed routing algorithm is designed to minimize the consumed time slots while guaranteeing the required time slots at all the pairs of adjacent nodes over the route and the contention neighbors of these nodes to support the route. Furthermore, the proposed routing algorithm can distribute the network loads well over the entire network. This technology is essential because video streaming applications require stringent quality of service and even larger network resources compared with traditional data services, and these demands may dramatically increase the entire network load and/or cause network congestion. Finally, experimental results are provided to show a performance of the proposed routing algorithm. Copyright

Smart Base Station-Assisted Partial-Flow Device-to-Device Offloading System for Video Streaming Services

This paper presents a smart base station-assisted partial-flow device-to-device offloading system that provides seamless video streaming services to clients by effectively offloading parts of the video traffic to D2D networks in order to alleviate the cellular network traffic load. In the proposed system, the main functionalities of the content centric networking (CCN) technology are deployed for efficient and fast cached content management at the base stations and in the devices. First, a logical overlay Chord-like network is constructed among the smart base stations for effectively handling significant numbers of the distributed contents. Then, content management protocols over the Chord-like network are implemented for rapidly finding the D2D server that contains the cached content requested by the D2D client. A two-stage PID-based LTE traffic controller is proposed to determine the amount of traffic to be offloaded to the D2D network among the cellular operator, the D2D servers, and the D2D clients. The proposed system is fully implemented using a CCNx open source and C/C++. Experimental results are provided to demonstrate the performance improvement of the proposed system.

Mobile Cloud-Based Interactive 3D Rendering and Streaming System Over Heterogeneous Wireless Networks

This paper presents an effective mobile cloud-based interactive 3D rendering and streaming system with data-service cost constraints over heterogeneous wireless networks. The proposed system contains software-defined networking (SDN)-enabled adaptive cloud resource management module and context-aware 3D rendering and streaming module to enhance the quality-of-service of interactive 3D rendering and streaming services. The first module is designed to efficiently control the limited cloud resources, such as server computing power and available backbone link bandwidth, and the second module is implemented to pursue an effective tradeoff between 3D rendering quality and compressed image quality. The system is implemented using Mininet network emulator with an OpenDay-light SDN controller, and VirtualGL with an online open-source 3D game, PlaneShift. Finally, the system is examined at a mobile device connected to real long-term evolution and WiFi networks.

Game-Theoretic Scalable Offloading for Video Streaming Services over LTE and WiFi Networks

This paper presents a game-theoretic scalable offloading system that provides seamless video streaming services by effectively offloading parts of video traffic in all video streaming services to a WiFi network to alleviate cellular network congestion. The system also consolidates multiple physical paths in a cost-effective manner. In the proposed system, the fountain encoding symbols of compressed video data are transmitted through long term evolution (LTE) and WiFi networks concurrently to flexibly control the amount of video traffic through the WiFi network as well as mitigate video quality degradation caused by wireless channel errors. Furthermore, the progressive second price auction mechanism is employed to allocate the limited LTE resources to multiple user equipment in order to maximize social welfare while converging to the ϵ-Nash equilibrium. Specifically, we design an application-centric resource valuation that explicitly considers both the realistic wireless network conditions and characteristics of video streaming services. In addition, the scalability and convergence properties of the proposed system are verified both theoretically and experimentally. The proposed system is implemented using network simulator 3. Simulation results are provided to demonstrate the performance improvement of the proposed system.

A P2P Overlay Multicast Tree Construction Algorithm Considering Peer Stability and Delay

This paper presents a P2P (Peer-to-Peer) overlay multicast tree construction algorithm to support stable multimedia service over the Internet. While constructing a multicast tree, it takes into account not only the link delay, but also peer stability. Since peers actually show dynamic and unstable behavior over P2P-based network, it is essential to consider peer stability. Furthermore, the weighting factor between link delay and peer stability is adaptively controlled according to the characteristics of the multicast tree. Basically, Genetic algorithm is employed to obtain a near optimal solution with low computational complexity. Finally, simulation results are provided to show the performance of the proposed algorithm.