Reliable and Energy-Efficient Hybrid Screen Mirroring Multicast System

This paper presents a reliable and energy-efficient hybrid screen mirroring multicast system for sharing high-quality real-time multimedia service with adjacent mobile devices over WiFi network. The proposed system employs overhearing-based multicast transmission scheme with Raptor codes and NACK-based retransmission to overcome well-known WiFi multicast problems such as low transmission rate and high packet loss rate. Furthermore, to save energy on mobile devices, the proposed system not only shapes the screen mirroring traffic, but also determines the target sink device and Raptor encoding parameters such as the number of source symbols, symbol size, and code rate while considering the energy consumption and processing delay of the Raptor encoding and decoding processes. The proposed system is fully implemented in Linux-based single board computers and examined in real WiFi network. Compared to existing systems, the proposed system can achieve good energy efficiency while providing a high-quality screen mirroring service.11Nsciescopu

Progressive Caching System for Video Streaming Services Over Content Centric Network

This paper presents a metafile-based progressive caching system over the content-centric networking (CCN) tree that supports seamless video streaming services with a high network utilization. In the proposed caching system, each CCN node uses a metafile made by a scalable caching algorithm for efficient and fast chunk caching management, and the reserved area of the CCN interest/data packet headers is used to deliver caching information among the CCN nodes. Based on this caching information, the proposed caching system determines the caching range of video data to minimize the required peak bandwidth for each link. The proposed caching system is implemented using the NS-3 based named data networking simulator. Furthermore, a real cellular wireless network testbed is realized with C/C++, open sources such as CCNx and Ubuntu MME, and a Raspberry PIs to examine the performance of the proposed caching system. The experiment results demonstrate the performance improvement achieved by the proposed caching system.11Ysciescopu

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 epsilon-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.111Nsciescopu

Security analysis and enhancements of an improved multi-factor biometric authentication scheme

Many remote user authentication schemes have been designed and developed to establish secure and authorized communication between a user and server over an insecure channel. By employing a secure remote user authentication scheme, a user and server can authenticate each other and utilize advanced services. In 2015, Cao and Ge demonstrated that An's scheme is also vulnerable to several attacks and does not provide user anonymity. They also proposed an improved multi-factor biometric authentication scheme. However, we review and cryptanalyze Cao and Ge's scheme and demonstrate that their scheme fails in correctness and providing user anonymity and is vulnerable to ID guessing attack and server masquerading attack. To overcome these drawbacks, we propose a security-improved authentication scheme that provides a dynamic ID mechanism and better security functionalities. Then, we show that our proposed scheme is secure against various attacks and prove the security of the proposed scheme using BAN Logic.111Ysciescopu

AL-FEC based HTTP Adaptive Streaming over Wireless Networks

본 논문에서는 AL-FEC 기반의 적응적 HTTP 스트리밍 시스템을 제안한다. 제안하는 시스템은 UDP 를 사용하여 빠르고 신뢰성 있는 데이터 전송을 제공하기 위해 Forward error correction(FEC)의 한 종류인 Raptor 코드를 사용한다. HTTP 서버는 여러 품질의 비디오 세그먼트뿐만 아니라 Raptor 인코딩을 통해 생성되는 각 세그먼트의 중복 데이터를 저장한다. 클라이언트는 세그먼트의 비트레이트와 중복 데이터의 양을 네트워크 상황에 맞게 적응적으로 결정한 후 이를 서버에게 요청한다. 제안하는 시스템은 리눅스 서버와 안드로이드 모바일 단말 상에서 실제로 구현하였으며, 실제 WiFi 네트워크 상에서 그 성능을 검증하였다.2

A NOVEL DYNAMIC AND SCALABLE CACHING ALGORITHM OF PROXY SERVER FOR MULTIMEDIA OBJECTS

This paper presents a novel dynamic and scalable caching algorithm of proxy server with a finite storage size for multimedia objects. Among the multimedia such as text, image, audio and video, video is a dominant component in terms of the performance of proxy server due to its traffic characteristics. For the fast caching process, caching sequences for videos are obtained to decrease both the buffer size and the required bandwidth and saved into metatiles in advance. Then, we present a novel caching and replacing algorithms for Multimedia objects based on the metatiles. Finally, experimental results are provided to show the superior performance of the proposed algorithm.X111Nsciescopu

HA2RS: HTTP Adaptive Augmented Reality Streaming System

IEEEThis paper presents a novel HTTP adaptive augmented reality (AR) streaming system. The goal of the proposed system is to provide high quality AR streaming services with low latency through a time-varying wireless network. In the proposed system, we employ a progressive mesh technique to enhance the scalability of AR streaming services, and adopt the metafile structure to support various attributes of progressive meshes necessary for rendering, displaying, and scheduling according to wireless network conditions. Based on this metafile, the proposed system requests the next chunk among AR contents to improve human visual perceptual quality considering the displaying scale values of AR contents on the screen. The proposed system is fully implemented by using well-known open sources (e.g., Android, OpenCV, OpenGL, and Nexus) and C/C++. Finally, the system is examined in real wireless network environments.11Nsciescopu

SCALABLE PROXY CACHING ALGORITHM MINIMIZING CLIENT'S BUFFER SIZE AND CHANNEL BANDWIDTH

This paper presents a scalable caching algorithm of proxy server with the finite storage size minimizing client's buffer size and constant-bit-rate channel bandwidth. Under the general video traffic condition, it is observed that the amount of decreased client's buffer size and channel bandwidth after caching a video frame depends on the relative frame position in the time axis as well as the frame size. Based on this fact, we propose an effective caching algorithm to select the cached frames by using the normalized buffer size. Finally, experimental results are provided to show the superior performance of the proposed algorithm. (c) 2005 Elsevier Inc. All rights reserved.X115sciescopu