Yazar "Cetinkaya, Cihat" seçeneğine göre listele

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    ALTO-assisted CDN-based Video Streaming over SDN
    (Ieee, 2017) Cetinkaya, Cihat; Sayit, Muge
    Software-defined Networking (SDN) is a promising network architecture for future internet applications by seperating the control and data layer of computer networks. On the other hand, Application Layer Traffic Optimization (ALTO) protocol provides ISP-friendly communication by provisioning network related information to the applications. In this paper, we propose a method for selecting appropriate video server using SDN and ALTO in content distribution network (CDN) based video streaming systems. Simulation results show that with the proposed method, the quality of experience received by the clients in video streaming applications is increased and the communication cost between internet service providers is reduced.
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    DASH-QoS: A scalable network layer service differentiation architecture for DASH over SDN
    (Elsevier, 2019) Sayit, Muge; Cetinkaya, Cihat; Yildiz, Huseyin Ugur; Tavli, Bulent
    As one of the key technologies residing in the future Internet concepts, Software Defined Networking (SDN) makes it possible to develop application-centric flow routing strategies. Thanks to the benefits offered by the SDN architecture, the performance of multimedia communication applications can be improved by developing application-centric flow routing strategies. Recently, MPEG-DASH standard which allows rate adaptation over HTTP has become popular. In this work, we present an architecture that provides increase in received quality of DASH clients running over an SDN domain. Within this architecture, we propose an optimization model which determines the streaming paths of the video packets of the clients. We also define different types of user classes and provide a guaranteed service and fairness among the users of the same class. Furthermore, we created a heuristic algorithm to facilitate the scalability of the solution. The simulation results show that, by considering the output of the optimization model and dynamically changing the routing paths in an ISP, the video quality offered to the DASH clients is significantly improved and a certain level of service guarantee is provided. (C) 2019 Published by Elsevier B.V.
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    Design of A Layer-based Video Streaming System over Software-Defined Networks
    (Ieee, 2017) Kalan, Reza Shokri; Cetinkaya, Cihat; Sayit, Muge; Mahmoodi, T; Secci, S; Cianfrani, A; Idzikowski, F
    Software Defined Networking (SDN) technology provides flexibility in routing of flows by separating data and control plane of computer networks. In addition to that, real-time traffic information can be inferred by using SDN. The advantages offered by SDN technology can be utilized to enhance the performance of network applications such as video streaming systems. In this paper, we propose a layered video streaming system to provide an increase in the performance achieved by video streaming clients running in an SDN domain. SDN controller runs an optimization algorithm that determines optimal video codec type and the number of layers based on the network conditions. Hence, the clients are directed to select appropriate video codec under the constraint of measured network conditions by SDN controller. We tested the performance of the proposed system by comparing with different approaches. The simulation results show that the performance of the proposed system outperforms the traditional best effort approach.
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    Evaluation of MPTCP Congestion Control for DASH
    (Ieee, 2017) Bikas, Shadi; Cetinkaya, Cihat; Sayit, Muge
    Dynamic Adaptive HTTP Streaming (DASH) is a popular MPEG standard. In DASH systems, the clients adapt quality based on the observed network and internal parameters in order to achieve high Quality of Experience (QoE). The throughput of Internet applications can be increased if the underlying transport protocol utilizes the network conditions by using multiple end-to-end connections. MPTCP is a recent technology that allows clients to open multiple TCP connections without requiring a change in the client software. In this paper, we investigate the performance of MPTCP when DASH clients use this protocol. The experimental results show that QoE achieved by the clients significantly changes due to congestion control algorithm that MPTCP uses.
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    Learning-based approach for layered adaptive video streaming over SDN
    (Elsevier, 2015) Uzakgider, Tuba; Cetinkaya, Cihat; Sayit, Muge
    Software-defined networking is a recently emerging paradigm that decouples the control and data planes of computer networks. It allows for the implementation of application-specific routing algorithms, and the advantages that the SDN architecture enables can be used to enhance the performance of multimedia communication applications. In this paper, we propose an adaptive video streaming system with a learning-based approach, running over SDN. In the proposed video streaming system, we use a novel learning model to determine the optimal time to re-route the traffic flows and to change the bitrate of the video. The learning model aims to minimize the packet loss rate, quality changes and controller cost while adapting the flow routes and video quality. We have tested the performance of the learning-based approach by comparing it to traditional Internet routing and the greedy approach. The results show that the proposed system significantly outperforms the traditional Internet routing approach and the greedy approach in terms of quality of experience (QoE) and network cost under different network scenarios. (C) 2015 Elsevier B.V. All rights reserved.
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    Parent Selection via Reinforcement Learning in Mesh-based P2P Video Streaming
    (Ieee Computer Soc, 2013) Sayit, Muge Fesci; Kaymak, Yagiz; Teket, Kemal Deniz; Cetinkaya, Cihat; Demirci, Sercan; Kardas, Geylani; Latifi, S
    There are several successful deployments of peer to peer (P2P) video streaming systems which provide acceptable QoS. Researches on these systems continue to improve the experienced quality by system users. Since received video quality mostly depends on the parent selection, an efficient parent selection algorithm can increase the received video bitrate by peers and provide seamless streaming. In this paper, we propose a novel parent selection method based on reinforcement learning. By the proposed system model, the newly joined peer explores the peers in the system first, and uses this information for its further parent selection actions. We implemented our model on a CoolStreaming-like P2P video streaming system in ns3. Our results indicate that, selected parents by using reinforcement learning approach improve the playback continuity, with respect to parent selection method used by CoolStreaming. Furthermore, reinforcement learning approach helps peers to find more stable parents in case of peer churn.
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    Parent Selection via Reinforcement Learning in Mesh-based P2P Video Streaming
    (Ieee Computer Soc, 2013) Sayit, Muge Fesci; Kaymak, Yagiz; Teket, Kemal Deniz; Cetinkaya, Cihat; Demirci, Sercan; Kardas, Geylani; Latifi, S
    There are several successful deployments of peer to peer (P2P) video streaming systems which provide acceptable QoS. Researches on these systems continue to improve the experienced quality by system users. Since received video quality mostly depends on the parent selection, an efficient parent selection algorithm can increase the received video bitrate by peers and provide seamless streaming. In this paper, we propose a novel parent selection method based on reinforcement learning. By the proposed system model, the newly joined peer explores the peers in the system first, and uses this information for its further parent selection actions. We implemented our model on a CoolStreaming-like P2P video streaming system in ns3. Our results indicate that, selected parents by using reinforcement learning approach improve the playback continuity, with respect to parent selection method used by CoolStreaming. Furthermore, reinforcement learning approach helps peers to find more stable parents in case of peer churn.
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    Performance Evaluation of DASH Rate Adaptation Algorithms
    (Ieee, 2015) Ozveren, Yalcin; Cetinkaya, Cihat; Sayit, Muge
    MPEG group has recently proposed Dynamic Adaptive HTTP Streaming (DASH) standard. Various rate adaptation algorithms were proposed in the literature in order to maximize the Quality of Experience (QoE) in DASH clients. In this paper, the performances of pioneer DASH clients, which implement rate adaptation algorithm by taking the bandwidth measurements, buffer level, and both parameters into account, are examined. For this purpose, QoE parameters according to the different buffer sizes are observed under variable network conditions in a simulation environment. The results enlighten that which type of approach in which circumstances can be used in order to obtain best performance in terms of QoE.
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    Rate Adaptation Algorithm with Backward Quality Increasing Property for SVC-DASH
    (Ieee, 2017) Ozcan, Simge Gizem; Kivilcim, Tugce; Cetinkaya, Cihat; Sayit, Muge
    Adapting quality based on the underlying network conditions is one of the most important components of video streaming applications. Today, HTTP adaptive video streaming systems are used prevalently around the world and this tendency led MPEG group to standardize DASH. Scalable video coding can be used as an alternative codec in DASH applications. In this case, quality adaptation can be done by adding or subtracting video layers. In this paper, we propose a rate adaptation algorithm for a DASH system that utilizes Scalable Video Coding (SVC) properties to increase Quality of Experience (QoE). Comparative simulation results show that as well as the storage and bandwidth efficiency advantages, scalable video coding is also advantageous in increasing QoE due to the quality increasing method.
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    Route Optimization for DASH over Software Defined Networks
    (Ieee, 2015) Cetinkaya, Cihat; Ozveren, Yalcin; Sayit, Muge
    In this paper, a method for the selection of the paths between the server and the clients for Dynamic Adaptive HTTP Streaming (DASH) over Software Defined Networks (SDN). In the proposed method, an optimization model is presented for increasing the Quality of Experience (QoE) in the clients by increasing the average received bitrates and for providing fairness by decreasing the difference between the bitrates received by the clients. Simulation results show that, thanks to the SDN technology, the QoE achieved by the DASH clients is improved by assigning streaming paths according to the proposed model.
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    A SCORE-BASED PACKET RETRANSMISSION APPROACH FOR PUSH-PULL P2P STREAMING SYSTEMS
    (Ieee, 2013) Sayit, Muge; Karayer, Erdem; Teket, Kemal Deniz; Kaymak, Yagiz; Cetinkaya, Cihat; Demirci, Sercan; Kardas, Geylani; Ganzha, M; Maciaszek, L; Paprzycki, M
    In this paper We propose an inference based packet recover)] technique which considers past scores indicating retransmission success of the peers. Past scores are calculated by considering several parameters such as requested packets availability and round trip time. The importance of packets to be retransmitted is also considered in the proposed model. In order to obtain comparable results, we also implement a different retransmission approach similar to the models proposed in the literature. The ns3 simulations show that retransmission model increases the Peak Signal to Noise Ratio (PSNR) value e\]en under high peer churn and limited resource index. Furthermore, score-based approach provides a decrease in reset counts and the number of duplicate packets, when it is compared to different retransmission approaches.
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    SDN for Segment based Flow Routing of DASH
    (Ieee, 2014) Cetinkaya, Cihat; Karayer, Erdem; Sayit, Muge; Hellge, Cornelius
    In this paper we propose an SDN based dynamic path selection for HTTP-based video streaming. MPEG-DASH is a recently proposed standard allowing rate adaptation over HTTP. On the other hand, Software Defined Networking (SDN) is a new network architecture, which allows determining routes of packet flows by an external controller software. In this study we develop an optimization model aiming to obtain maximum throughput for DASH services by selecting the optimal paths for video packet flows over SDN. The simulations show that the clients in the proposed system receive better QoE in terms of video bitrate, outage duration and startup delay when compared to the clients running in Internet's best effort.
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    An SDN-assisted System Design for Improving Performance of SVC-DASH
    (Ieee, 2015) Cetinkaya, Cihat; Ozveren, Yalcin; Sayit, Muge; Ganzha, M; Maciaszek, L; Paprzycki, M
    Today, the most of the video streaming system provides quality adaptation and prefers to send their packets over HTTP. MPEG group has standardized Dynamic Adaptive HTTP Streaming (DASH) regarding this tendency on the adaptive HTTP streaming. Besides providing quality adaptation with a non-scalable codec, DASH standard also allows Scalable Video Coding (SVC) to adapt quality. Software Defined Networks (SDN) is a recently emerged networking paradigm. SDN enables to separate control and data plane of computer networks and hence provides flexibility to network operators to implement their own routing approaches. In this paper, we propose a system for increasing Quality of Experience (QoE) of SVC-DASH clients by utilizing SDN. Our experimental results show that the proposed system provides an increase in received video quality and decrease in outage duration and startup delay when compared to the performance of the client running over todays Internet implementing shortest path routing.
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    Segment-aware dynamic routing for DASH flows over software-defined networks
    (Wiley, 2020) Cetinkaya, Cihat; Herguner, Korhan; Hellge, Cornelius; Sayit, Muge
    Most of the video streaming applications running over the Internet send video data over HTTP and provide an architecture for video clients to adapt video quality during streaming. in HTTP adaptive streaming, a raw video is encoded at various qualities, each encoded video file is divided into small segments, and the clients may change the segment quality by sending requests for segments having different qualities over time. MPEG has standardized dynamic adaptive streaming over HTTP (MPEG-DASH) due to this tendency. in this work, we focus on DASH over software-defined networks (SDN), and we dynamically reroute DASH flows by considering the current network capacity, available bandwidth of the paths, and bitrate of the segments in order to provide high quality of experience (QoE) and fairness among DASH clients. Simulations performed under various network conditions show that the proposed study provides higher QoE and fairness compared with the max-flow routing approach.
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    Server Selection for Video Streaming Applications over Software Defined Networks
    (Ieee, 2016) Kaysudu, Elifnur; Cetinkaya, Cihat; Herguner, Korhan; Sayit, Muge
    Software Defined Networks (SDN) is a new technology providing a programmable network by separating control and data planes of computer networks. SDN technology can provide an increase in the performance of Internet applications by implementing routing approaches specific to such applications. In this paper, we propose a server and end-to-end path selection approach for a content distribution network (CDN) based video streaming system. Simulation results show that the proposed approach can increase the performance of CDN based video streaming systems.
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    Towards QoS-aware Routing for DASH Utilizing MPTCP over SDN
    (Ieee, 2017) Herguner, Korhan; Kalan, Reza Shokri; Cetinkaya, Cihat; Sayit, Muge
    Multipath TCP (MPTCP) has gained great attention by the researchers and network application developers due to its features providing better bandwidth utilization and higher reliability recently. Utilizing MPTCP in the datacenters provides performance gain to the applications. If the underlying network has Software Defined Networking (SDN) architecture, the routing of the MPTCP subflows can be specialized. In this paper, we propose an architecture utilizing MPTCP in an SDN-based ISP in order to serve guaranteed services to the video streaming clients. The number of MPTCP subflows and routes of the subflows are determined based on a mixed integer linear programming model. The simulation results show that the proposed architecture provides increase in received throughput and decrease in duration of outages when it is compared to a general-purposed throughput maximization approach.
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    Vascular Landmark Classification in Retinal Images Using Fuzzy RBF
    (Ieee, 2013) Candemir, Cemre; Cetinkaya, Cihat; Kilincceker, Onur; Cinsdikici, Muhammed
    This paper suggests the use of radial based neural networks for classification of the landmark points from retina vessels in the retinal vascular images to diagnose the disease in the diabetic retinopathy patients and to track the periodic differences in retinal vessel images. In the suggested method, Gold Standard images from DRIVE database are used. The performance of landmark detection by the suggested method shows that the method can be used as an algorithm for registration of retinal images.
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    Vascular Landmark Classification in Retinal Images Using Fuzzy RBF
    (Ieee, 2013) Candemir, Cemre; Cetinkaya, Cihat; Kilincceker, Onur; Cinsdikici, Muhammed
    This paper suggests the use of radial based neural networks for classification of the landmark points from retina vessels in the retinal vascular images to diagnose the disease in the diabetic retinopathy patients and to track the periodic differences in retinal vessel images. In the suggested method, Gold Standard images from DRIVE database are used. The performance of landmark detection by the suggested method shows that the method can be used as an algorithm for registration of retinal images.
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    Video-on-Demand System Architecture with ALTO-SDN Integration
    (Ieee, 2016) Cetinkaya, Cihat; Sayit, Muge
    Software Defined Networking (SDN) is a promising technology for future internet applications through decoupling the data and control planes of computer networks. Enabling the development of application specific routing algorithms, the separation fosters the performance of internet applications. On the other hand, Application Layer Traffic Optimization (ALTO) provides network related information such as network paths and geographic locations of hosts to applications running on the internet. Thus, it is possible to maintain an increase in the performance of the end-to-end internet applications by integrating SDN technology and ALTO protocol. In this paper, we propose a Video-on-Demand (VoD) architecture utilizing the integration of SDN and ALTO. In the architecture, the clients running the VoD applications reside in an SDN domain while the servers remain out of the SDN domain. Simulation results show that the integration of SDN and ALTO increases the Quality of Experience (QoE) in a VoD system compared to QoE which is achieved in a traditional VoD architecture.