Researcher:
Sunay, Mehmet Oğuz

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Mehmet Oğuz

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Sunay

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Sunay, Mehmet Oğuz

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2004 - 200830

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Researcher Of Publications: search.filters.isAuthorOfPublication.47353ba6-2b5b-4662-9c47-3366d3e7f2dc

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    Application QoS fairness in wireless video scheduling
    (Institute of Electrical and Electronics Engineers (IEEE), 2006) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; Sunay, Mehmet Oğuz; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; 26207; 16372; N/A
    The video pre-roll delay for filling up the client buffer can not be too long for user utility and buffer limitations in wireless point-to-multipoint streaming systems. Cross-layer design that deals with both physical and application layer aspects jointly is necessary for this purpose. We present a cross-layer optimized multiuser video adaptation and user scheduling framework for wireless video communication, where Quality-of-Service (QoS) fairness among users is provided with maximum video quality and video throughput. Both protocol layers are jointly optimized using a single Multi-Objective Optimization (MOO) framework that aims to schedule the user with the least remaining playback time and the highest video throughput (delivered video seconds per transmission slot) with maximum video quality. Experiments carried out in the IS-856 (1×EV-DO) standard and ITU pedestrian and vehicular environments demonstrate the improvements over the state-of-the-art schedulers in terms of video QoS fairness, video quality and throughput. / İstemci arabelleğini doldurmak için videodan önce gösterilen reklam gecikmesi, kablosuz noktadan çok noktaya akış sistemlerinde kullanıcı yardımcı programı ve arabellek sınırlamaları için çok uzun olamaz. Bu amaç için hem fiziksel hem de uygulama katmanı özelliklerini birlikte ele alan çapraz katman tasarımı gereklidir. Kablosuz video iletişimi için, kullanıcılar arasında Hizmet Kalitesi (QoS) adaletinin maksimum video kalitesi ve video çıkışı ile sağlandığı, katmanlar arası optimize edilmiş çok kullanıcılı bir video uyarlaması ve kullanıcı planlama çerçevesi sunuyoruz. Her iki protokol katmanı, kullanıcıyı maksimum video kalitesiyle en az kalan oynatma süresi ve en yüksek video verimi (iletim yuvası başına iletilen video saniyesi) ile programlamayı amaçlayan tek bir Çok Amaçlı Optimizasyon (MOO) çerçevesi kullanılarak ortaklaşa optimize edilmiştir. IS-856 (lxEV-DO) standardında ve ITU yaya ve araç ortamlarında gerçekleştirilen deneyler, video QoS adaleti, video kalitesi ve verim açısından en son teknoloji zamanlayıcılara göre iyileştirmeler göstermektedir.
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    Fair scheduling for spectrally efficient multi-service wireless data provisioning
    (Wiley, 2004) N/A; Department of Electrical and Electronics Engineering; N/A; Sunay, Mehmet Oğuz; Ekşim, Ali; Faculty Member; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A
    Efficient wireless packet data access is possible by exploiting multi-user diversity. This is done by using an opportunistic multiple access system that allocates system resources to one user at a time while using adaptive modulation and coding. Based on this outcome, recently the IS-856 system was developed. A scheduling algorithm provides resource allocation in the IS-856 system, and its proper design is perhaps one of the most crucial aspects ensuring good system performance. We present a number of such algorithms in this paper, two of which are new, and provide a comparative performance evaluation. The proposed algorithms appear to have the best overall performance of achieving high system throughputs without diverging much from the optimal latency performance. We then show that the IS-856 system can easily be adjusted to provide a multitude of services, each with different QoS requirements. Extensive performance evaluations show that good system performance can be maintained in the multi-service scenario. The paper also presents means of providing multicast service provisioning in the IS-856 system.
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    Efficient resource allocation for statistical QOS assurances in HDR based wireless packet data
    (Ieee, 2004) N/A; Department of Electrical and Electronics Engineering; Akgül, Ferit Ozan; Sunay, Mehmet Oğuz; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A
    In this paper we present new scheduling algorithms for the HDR wireless packet data system to provide superior statistical QoS guarantees. Here, instead of QoS assurances we guarantee the percentage of time the QoS requirements are satisfied and develop new scheduling algorithms accordingly. We compare these schedulers with the maximum rate, proportional fair and exponential rules from the literature. We observe that the statistical QoS guarantee is an attractive alternative to the assured QoS for the wireless platform since such strict QoS assurances decrease the wireless system performance significantly.
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    Amplify-and-forward capacity with transmit beamforming for MIMO multiple-relay channels
    (IEEE, 2007) Yılmaz, Erhan; Department of Electrical and Electronics Engineering; Sunay, Mehmet Oğuz; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; N/A
    In this paper, we consider a MIMO wireless relay network where communication between a source and a destination node is assisted by multiple relay nodes using the Amplify-and-Forward (AF) strategy. We consider a system where the source node multiplexes the information into parallel streams and uses disjoint subsets of relays to assist the transmission of each stream. Furthermore, we assume that the source and the destination have the same number of antennas and that each transmit antenna is virtually paired to a different destination antenna. We consider source node channel side information (CSI) availability of just the source-relay and source-destination links, and propose a source beamforming method based on maximizing the Sum of Signal-to-Leakage Ratios (SSLR) for all of the data streams. This method maximizes the sum of signal strengths at the set of relay nodes assigned to that stream while suppressing the interference to other relay nodes. Maximizing the SSLR reduces the propagation of interference terms in the AF strategy and results in significant performance gains.
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    Statistical qos assurances for high speed wireless communication systems
    (Springer-Verlag Berlin, 2006) N/A; Department of Electrical and Electronics Engineering; Akgül, Ferit Ozan; Sunay, Mehmet Oğuz; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A
    In this paper we propose the use of statistical QoS guarantees for transmission over the wireless channel. Here, instead of QoS assurances we propose to guarantee the percentage of time the QoS requirements are satisfied. We present an associated scheduling algorithm for the opportunistic multiple access system. We compare the proposed scheduler with popular schedulers from the literature. We observe that the statistical QoS guarantee is an attractive alternative to the assured QoS for the wireless platform since such strict QoS assurances decrease the wireless system performance significantly.
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    An analysis of constant bitrate and constant PSNR video encoding for wireless networks
    (Institute of Electrical and Electronics Engineers (IEEE), 2006) De Vito, F.; De Martin, J.C.; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; Sunay, Mehmet Oğuz; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; 26207; 16372; N/A
    In wireless networks, transmission of constant-quality, high bitrate video is a challenging task due to channel capacity and buffer limitations. Content adaptive rate control, is used as a solution to this problem. Instead of transmitting all of the video content at low quality, the most important content can be transmitted at high quality while still preserving an acceptable quality for the remaining segments. Furthermore, the rate control strategy inside the individual temporal segments plays a key role for the network performance and viewing quality. Although constant quality video encoding inside the temporal segments is preferable for the best viewing experience, it causes more network packet losses due to adverse bitrate fluctuations in the video stream. In cases when the network is too much loaded, it may be better to employ constant bitrate encoding for network friendliness. In this paper, a performance analysis of constant bitrate and constant peak signal-to-noise ratio encoding for content adaptive rate controlled video streaming over wireless networks is presented. Experimental results obtained using AVC/H.264 encoding in a CDMA/HDR multi-user environment with cross-layer optimized scheduling show performance comparisons of CBR and CPSNR encoding.
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    Video streaming over wireless dccp
    (IEEE, 2008) N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Görkemli, Burak; Sunay, Mehmet Oğuz; Tekalp, Ahmet Murat; PhD Student; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 26207
    It is envisioned that access networks will be mostly wireless in the future. Hence, it is of interest to consider extensions of the Datagram Congestion Control Protocol (DCCP) for wireless networks. This paper focuses on the problems of video streaming over DCCP in the wireless domain and proposes a cross-layer solution in which the wireless packet loss information available in the Medium access (MaC) layer is utilized by DCCP to distinguish congestion losses from wireless losses and behave accordingly. Tests performed with our modified DCCP confirm that using cross-layer loss information prevents unnecessary rate decreases and results in better video streaming experiences.
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    Cross-layer scheduling with content and packet priorities for optimal video streaming over 1xEV-DO
    (Springer-Verlag Berlin, 2006) De Martin, Juan Carlos; N/A; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; De Vito, Fabio; Sunay, Mehmet Oğuz; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; PhD Student; Other; Faculty Member; Faculty Member; Faculty Member; Department of Computer Engineering; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; N/A; N/A; 26207; 16372
    Maximization of received video quality and application-level service fairness are the two principal objectives of multi-user wireless video streaming. The user and packet scheduling mechanisms employed are the determining factors on the communication system performance and must utilize multiple layers of the OSI protocol stack. The semantic and decodability (concealment related) importance and hence priorities of video packets can be considered at the application layer. In this paper, the use of video content and packet priorities for multi-objective optimized (MOO) scheduling in 1xEV-DO system is introduced. Rate adaptive AVC/H.264 encoding is used for content adaptation and a user with the least buffer fullness, best channel throughput and highest video packet importance is targeted for scheduling. Hence, losses are forced to occur at packets with low semantic/decodability importance. Results show that the proposed framework achieves 1-to-2 dB's better PSNR in high importance temporal regions compared to the state-of-the-art CBR encoding case.
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    Cross-layer design for wireless H.264/AVC video broadcasting system
    (IEEE, 2007) N/A; Department of Electrical and Electronics Engineering; Atıcı, Çağdaş; Sunay, Mehmet Oğuz; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A
    Wireless video broadcasting is a complicated problem in which the number of users receiving the service and the average received video quality have to be intelligently optimized. In this paper, we propose a novel, multiple objective optimized cross-layer H.264/AVC video broadcasting scheme for a wireless system that supports a variety of transmission data-rates. The optimal compromise operating point, which includes H.264/AVC and physical layer parameters, between the maximization of the average received video PSNR and the minimization of the service outage probability is found using the multi-objective, cross-layer optimization. Simulations done for the ITU Pedestrian A and Vehicular B channels show that high-data rates with low outages are possible for video broadcasting using a cross-layer design.
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    A cross-layer approach for minimum delay content adaptive video streaming over variable bitrate channels
    (European Association for Signal Processing, 2005) N/A; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Özçelebi, Tanır; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; Sunay, Mehmet Oğuz; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; College of Engineering; N/A; 26207; 16372; N/A
    A novel cross-layer scheduling and stream switching algorithm for content and channel adaptive video streaming over 1xEV-DO (CDMA-HDR), where stream switching is done according to the receiver buffer level is presented. The instantaneous transmission rate to each user is determined by a multi-objective optimized scheduler, maximizing network throughput and individual receiver buffer levels simultaneously, while the instantaneous coding rate for each user is determined according to buffer status feedback. The transmitter always switches to the most suitable pre-optimized bitstream with minimum delay and visual distortion calculated for various channel capacity values and under constant bitrate assumption. The main target of the proposed framework is to guarantee continuous playout of the transmitted content at all user devices while providing maximum system throughput, minimum overall distortion and minimum pre-roll delay. Experimental results show that decoder buffer overflows and underflows that cause pauses in the playout are prevented as opposed to the case without stream switching.