Evaluation of quality scalability techniques for video transmission

The significant increase of the transmission of multimedia content over Internet are demanded new delivery strategies to assure a good quality of experience of the users. Transmission of video over packet networks is not an easy task due to multiple fluctuations of the network conditions. One possibility to improve the quality of some video streaming services is the combinate use of the scalable video coding and cross layer mechanisms that allow applications to adapt its traffic stream to the resources network that are available. In this paper, it is presented a performance evaluation of the three main scalability techniques: CGS (Coarse-Grained Scalability), FGS (Fine Grain scalability) and MGS (Medium Grain Scalability). In particular, we focus on determining what method is more appropriated for video transmission taking into account some video quality metrics like PSNR (Peak Signal-to-Noise Ratio) and decoded frame rate. The results reveal that the rate-adaptive strategy and the MGS technique help avoid or reduce the congestion in networks obtaining a better quality in the received videos.Comment: 12 pages, 11 figures. Language Spanish. This work is a Chapter of the eBook: "Avances de la Ingenieria Bonaventuriana". ISBN 978-958-8928-85-2 Bogota. Colombia. 201

Analysis and Optimization of Service Delay for Multi-quality Videos in Multi-tier Heterogeneous Network with Random Caching

Aiming to minimize service delay, we propose a new random caching scheme in device-to-device (D2D)-assisted heterogeneous network. To support diversified viewing qualities of multimedia video services, each video file is encoded into a base layer (BL) and multiple enhancement layers (ELs) by scalable video coding (SVC). A super layer, including the BL and several ELs, is transmitted to every user. We define and quantify the service delay of multi-quality videos by deriving successful transmission probabilities when a user is served by a D2D helper, a small-cell base station (SBS) and a macro-cell base station (MBS). We formulate a delay minimization problem subject to the limited cache sizes of D2D helpers and SBSs. The structure of the optimal solutions to the problem is revealed, and then an improved standard gradient projection method is designed to effectively obtain the solutions. Both theoretical analysis and Monte-Carlo simulations validate the successful transmission probabilities. Compared with three benchmark caching policies, the proposed SVC-based random caching scheme is superior in terms of reducing the service delay.Comment: 13 pages, 8 figures, IEEE Systems Journal, Accepte