Browsing by Author "Sayit, Muge"

Now showing 1 - 4 of 4

Citation - WoS: 1
Adaptive Video Streaming With H.264 Sp Frames
(Pamukkale Univ, 2012) Sayit, Muge; Tunali, E. Thrhan
In this work, SP frames of the extended profile of H.264 AVC video codec are utilized to obtain efficient switching for actual video streaming experiments on the Internet. An adaptive algorithm is developed and by using this algorithm, performance of SP frames is compared with that of standard I-frame switching. Detailed measurements of network conditions are given for each experiment to indicate that comparisons are carried out in fair conditions. It has been observed that, under certain conditions, SP frames can improve performance considerably whereas in the others, they may only introduce overhead. Based on this observation different GOP patterns are proposed for different video type-congestion level combinations.
Citation - WoS: 6
Citation - Scopus: 5
Adaptive, Incentive and Scalable Dynamic Tree Overlay for P2p Live Video Streaming
(Springer, 2016) Sayit, Muge; Demirci, Sercan; Kaymak, Yagiz; Tunali, E. Turhan
In this paper, we propose a new multicast tree framework to be used in peer-to-peer (P2P) live video streaming systems. The proposed system, adapts the tree links under high peer churn and runs in a totally distributed manner. In order to provide this dynamism and seamless streaming at the same time, we propose a cross layer design involving scalable video codec, backup parents and hierarchical clusters. The performance of the system is measured in real world environment PlanetLab that has nodes distributed all over the world. The experiments show that the proposed system provides high quality of experience (QoE) in terms of Peak Signal to Noise Ratio (PSNR), playback delay and duration of pauses. The proposed system also provides incentive mechanism to its users.
Citation - WoS: 12
Citation - Scopus: 13
A Hierarchical P2p Clustering Framework for Video Streaming Systems
(Elsevier, 2017) Demirci, Sercan; Yardimci, Asil; Sayit, Muge; Tunali, E. Turhan; Bulut, Hasan
In this study, a novel overlay architecture for constructing hierarchical and scalable clustering of Peer-to-Peer (P2P) networks is proposed. The proposed architecture attempts to enhance the clustering of peers by incorporating join, split, merge and cluster leader election mechanisms in a fully distributed manner. It takes delay proximity of peers into account as distance measure. By constructing hierarchical clustering of peers, the control message overhead and maintenance such as host departure/host join overhead are decreased. Theoretical comparisons on overheads of the proposed system with that of other systems from literature are studied. The control mechanism for dynamic peer behavior of the architecture is tested over PlanetLab. The performance metrics used are end-to-end delay, diameter, cluster head distance, occupancy rate, peer join latency, accuracy and correctness. The test results are compared with Hierarchical Ring Tree (HRT) and mOverlay architecture. In addition, a P2P video streaming application is run over the proposed network overlay. Streaming tests show that video streaming applications perform well in terms of received video quality if hierarchical clusters considering delay proximity are used as underlying network architecture. (C) 2016 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
Optimal Backup Parent Pools for Resilient Multicast Trees on Peer-To Networks
(Tubitak Scientific & Technical Research Council Turkey, 2015) Tunali, Emrullah Turhan; Sayit, Muge
Due to churn as well as node and link failures in peer-to-peer (P2P) networks, providing resilient multicast is a challenging issue, particularly for overlay trees. In this work, we first study analytical properties of the backup parent pool that aims at improving the resilience of overlay multicast trees in P2P video streaming. We then present a novel greedy degree-constrained multicast tree construction algorithm that addresses the tradeoffs between maximizing resiliency, maximizing bandwidth utilization, and minimizing delay. The choice of essential design parameters is studied together with seamlessness of the streaming under a variety of fault scenarios. Simulation results indicate that the overhead introduced by the mechanism is negligible if there is sufficient bandwidth in the system. Both analytic and simulation results indicate that the proposed approach improves resiliency, bandwidth utilization, and delay. Comparisons with an algorithm from the literature are carried out and it is observed that the proposed method is superior under a wide range of conditions.