P2broadcast: a hierarchical clustering live video streaming system for P2P networks

This work describes a novel live video streaming system for P2P networks, referred to as P2broadcast. The video streaming service has bandwidth requirements to guarantee presentation quality. Therefore, a scalable strategy to quickly find a path from a media server to a client with abundant bandwidth is very important. A common approach in the literature is the bandwidth first (BF) scheme, which allows a newcomer to adopt a BF tree traversal scheme to find its parent peer on the P2P overlay tree to retrieve the media content. The BF scheme is likely to build a deep overlay tree, resulting in long start‐up latency as the number of peers on the overlay tree grows. P2broadcast reduces start‐up latency by organizing peers into hierarchical clusters and making the overlay tree become a ‘short‐and‐wide’ tree. The hierarchical clustering structure enables a newcomer to find its parent peer among the set of peers that are more likely to provide large available bandwidth only. Limiting the set of potential parent peers not only reduces start‐up latency but also improves the system availability. Additionally, unlike the BF scheme that only concerns available bandwidth, P2broadcast utilizes a cost function to evaluate the appropriateness of a potential parent peer. The cost function considers the depth of the newcomer on the overlay tree, making the overlay tree become a short‐and‐wide tree. In addition to start‐up latency reduction, the short‐and‐wide tree feature also alleviates the service interruption probability due to the leaving or failure of a peer. Our simulation results show that P2broadcast greatly outperforms the BF scheme in terms of system availability, and achieves around 66% savings in start‐up latency and 10% decrement in service interruption probability. Copyright © 2005 John Wiley & Sons, Ltd.     

Server-Aided Adaptive Live Video Streaming Over P2P Networks

Three factors, including churn of peers, high transmission delay, and high bandwidth heterogeneity, jointly bring forward great challenges to video streaming over P2P networks. In this paper, the multi-tree approach is leveraged to construct an overlay with resilience to churn and low transmission delay. For such a multi-tree structured overlay, a server-aided adaptive video streaming scheme is proposed to cope with the bandwidth heterogeneity. During streaming process, video data are collaboratively forwarded to the same receiver by multiple peers based on side information and network condition, as well as the distributed bitstream is dynamically switched among multiple available versions in a rate-distortion optimized way by the streaming server. Simulation results show that the proposed scheme achieves great gain in overall perceived quality over simple heuristic schemes.     

Adaptive video protection in large scale peer‐to‐peer video streaming over mobile wireless mesh networks

Because video streaming over mobile handheld devices has been of great interest, the necessity of introducing new methods with low implementation cost and scalable infrastructures is a strong demand of the service. In particular, these requirements are present in popular wireless networks such as wireless mesh networks (WMN). Peer‐to‐peer (P2P) networks promise an efficient scalable network infrastructure for video streaming over wired and wireless networks. Limited resources of the peers in P2P networks and high error rate in wireless channels make it more challenging to run P2P streaming applications over WMNs. Therefore, it is necessary to design efficient and improved error protection methods in P2P video streaming applications over WMNs. In this paper, we propose a new adaptive unequal video protection method specially intended for large scale P2P video streaming over mobile WMNs. Using this method, different frames have different priorities in receivers along the recovery process. Moreover, we precisely and completely evaluate different aspects related to frame protection in these networks using five important performance metrics including video distortion, late arrival distortion, end‐to‐end delay, overhead and initial start‐up delay. The results obtained from a precise simulation in OMNeT++ show that the proposed adaptive method significantly outperforms other solutions by providing better video quality on mobile wireless nodes. Copyright © 2015 John Wiley & Sons, Ltd.     

A distributed utility‐based scheduling for peer‐to‐peer video streaming over wireless networks

Interactive multimedia applications such as peer‐to‐peer (P2P) video services over the Internet have gained increasing popularity during the past few years. However, the adopted Internet‐based P2P overlay network architecture hides the underlying network topology, assuming that channel quality is always in perfect condition. Because of the time‐varying nature of wireless channels, this hardly meets the user‐perceived video quality requirement when used in wireless environments. Considering the tightly coupled relationship between P2P overlay networks and the underlying networks, we propose a distributed utility‐based scheduling algorithm on the basis of a quality‐driven cross‐layer design framework to jointly optimize the parameters of different network layers to achieve highly improved video quality for P2P video streaming services in wireless networks. In this paper, the quality‐driven P2P scheduling algorithm is formulated into a distributed utility‐based distortion‐delay optimization problem, where the expected video distortion is minimized under the constraint of a given packet playback deadline to select the optimal combination of system parameters residing in different network layers. Specifically, encoding behaviors, network congestion, Automatic Repeat Request/Query (ARQ), and modulation and coding are jointly considered. Then, we provide the algorithmic solution to the formulated problem. The distributed optimization running on each peer node adopted in the proposed scheduling algorithm greatly reduces the computational intensity. Extensive experimental results also demonstrate 4–14 dB quality enhancement in terms of peak signal‐to‐noise ratio by using the proposed scheduling algorithm. Copyright © 2015 John Wiley & Sons, Ltd.     

Rate-distortion based real-time wireless video streaming

This paper presents wireless video streaming techniques that exploit the characteristics of video content, transmission history, and physical layer channels to enable real-time efficient video streaming over wireless networks to a wireless client. The key contribution of the proposed video streaming techniques is the use of rate-distortion based, but simplified, low complexity packet scheduling as well as forward error correction (FEC) rate selection. To this end, we develop an optimization framework that jointly schedules the packets and selects the FEC rates. The rate-distortion optimized packet scheduling and FEC rate selection provides the optimum quality video on the receiver side albeit at a high computational cost. By some intelligent approximations, rate distortion optimized packet scheduling and FEC rate selection technique is transformed into two sub-optimal but low complexity video streaming techniques that can provide high video quality. We perform extensive simulations to understand the performance of our proposed techniques under different scenarios. Results show that, the proposed techniques improve video quality on the average by 4 dB. We conclude that significant benefits to end-user experience can be obtained by using such video streaming methods.     

GaMe‐PLive: a new game theoretic mechanism for P2P live video streaming

GaMe‐PLive is a game theoretical framework for peer‐to‐peer live video streaming. Prevention of free‐riding and minimization of loss rate in video data transmission are the important objectives of the proposed framework. GaMe‐PLive is also extremely evasive about overhead of extra control messages exchange. At first, a static game with complete information between peers is described, which models the peer's interactive decision process for acceptance/rejection of a video chunk request. All peers repeatedly play this game during video playback periodically. Afterwards, the proposed game is analyzed to obtain a Nash equilibrium, which determines a peer's best strategic response for participation in the video chunk distribution. It will be proved that by applying some simple and feasible conditions, the desired objectives can be reached. The experimental results reveal that the proposed system has been successful in detecting free‐riders with negligible false negative and false positive rate. Also, tolerable loss chunk percentage has been satisfied in all performed tests. Besides, an interesting social norm emerges in GaMe‐PLive: Less participation leads to more missing chunks. GaMe‐PLive will be proven to be quite resistant against cheating peers. The proposed framework displays high performance even if there is not a video server with high upload bandwidth. Copyright © 2015 John Wiley & Sons, Ltd.     

A novel joint transmission and caching optimizing scheme in multirelay networks: Video service quality assurance scheme

The demands of instant video communication have recently increased as a means to improve user experience. Meanwhile, the cache mechanism has become an effective technology used in video transmission so that delay jitter could be reduced to a insignificant value. We propose a novel video service quality assurance scheme in multirelay networks (MRNs) with cache. Both wireless channel state information on the transmitting side and optimal receiver schemes on the receiving side are considered in the proposed scheme. We derive closed form expressions of video streaming for cache‐based MRN and investigate the impact of cache length when it is changed. Then, we proved that the optimal solution is difficult to acquire, and the suboptimal solution could be achieved by decomposing the original optimization problem into several simpler subproblems, which include graph and convex optimization. Specifically, we obtain a limit for the cache queuing model in MRNs. Detailed algorithms with corresponding theoretical reasoning are provided as well. Simulations demonstrate the effectiveness of our proposed scheme by comparing with some other existed high–video‐quality transmission schemes. The analysis also shows that our scheme outperforms others in jitter reducing.     

Efficient slice‐aware H.264/AVC video transmission over time‐driven priority networks

This paper proposes a multimedia streaming architecture that combines network and video technologies to handle video traffic over multi‐hop access networks. In this context, resource overprovision typical of current quality of service approaches will become a limiting factor because of the increasing spread of bandwidth‐intensive multimedia applications. The proposed scheme adopts a time‐driven priority scheduling at network nodes and exploits slice classification at the video encoder to differentiate packets. The service guarantees offered by time‐driven priority, together with the packet classification, significantly reduce congestion and increase the video quality at the receiver with respect to the traditional differentiated services (DiffServ) approach, also achieving high resource utilization. This is an important result, as current DiffServ‐based architectures are far from obtaining such resource utilization in conjunction with reasonable delays and jitters. Copyright © 2013 John Wiley & Sons, Ltd.     

Design and Implementation of a Network‐Adaptive Mechanism for HTTP Video Streaming

This paper proposes a network‐adaptive mechanism for HTTP‐based video streaming over wireless/mobile networks. To provide adaptive video streaming over wireless/mobile networks, the proposed mechanism consists of a throughput estimation scheme in the time‐variant wireless network environment and a video rate selection algorithm used to increase the streaming quality. The adaptive video streaming system with proposed modules is implemented using an open source multimedia framework and is validated over emulated wireless/mobile networks. The emulator helps to model and emulate network conditions based on data collected from actual experiments. The experiment results show that the proposed mechanism provides higher video quality than the existing system provides and a rate of video streaming almost void of freezing.     

P2P流媒体模型的资源传输机制

针对流媒体的点播和直播服务,提出了基于P2P的流媒体应用层多播和点播的解决方案,构建了基于超级节点和普通节点的两层体系结构的视频流媒体模型.描述了模型的总体结构,分析了资源传输机制.基于校园网对模型进行了测试,测试结果表明,模型能够实现基于流媒体应用的多点数据快速互传.     

GPSA：一种在异构环境下贪婪式基于拉式调度方法的P2P视频直播

Pull-based P2P live streaming is a promising solution for the large scale streaming systems, like PPStream, PPlive, due to its high scalability, low cost and high resilience. However, they usually suffer from bad delay performance. In this paper, we seek to improve the delay performance under ensuring video display quality stemming from chunk scheduling. And so we model Pull-based chunk scheduling problem as a multi-objective optimization problem to minimize the video delay and maximize video display qualit...     

Exploiting scheduling and free‐riding for offline downloading in BitTorrent networks

Recently, the peer‐to‐peer (P2P) architecture has become a popular scheme for Internet users to rapidly exchange files. As reported in previous studies, P2P traffic accounts for a significant portion of overall Internet traffic. Many computing resources, for example, network bandwidth and disk space, may be consumed by P2P clients. Accordingly, in this paper, we devise a novel scheme that integrates advantageous features of both the conventional client–server and the P2P architectures to create an offline downloading service. Specifically, the proposed service acts as an agent that downloads required files from the BitTorrent network without consuming local computing resources. In other words, users can stay offline during the download process. Because the proposed scheme aims to provide service to numerous users at the same time, a proper scheduling technique is adopted to achieve better download performance. Moreover, a free‐riding mechanism is seamlessly incorporated with the proposed priority queuing to facilitate more effective bandwidth utilization. Empirical studies show that our scheme is promising in practical applications. Copyright © 2012 John Wiley & Sons, Ltd.     

Managing QoS requirements for video streaming: from intra‐node to inter‐node

Streaming video over IP networks has become increasingly popular; however, compared to traditional data traffic, video streaming places different demands on quality of service (QoS) in a network, particularly in terms of delay, delay variation, and data loss. In response to the QoS demands of video applications, network techniques have been proposed to provide QoS within a network. Unfortunately, while efficient from a network perspective, most existing solutions have not provided end‐to‐end QoS that is satisfactory to users. In this paper, packet scheduling and end‐to‐end QoS distribution schemes are proposed to address this issue. The design and implementation of the two schemes are based on the active networking paradigm. In active networks, routers can perform user‐driven computation when forwarding packets, rather than just simple storing and forwarding packets, as in traditional networks. Both schemes thus take advantage of the capability of active networks enabling routers to adapt to the content of transmitted data and the QoS requirements of video users. In other words, packet scheduling at routers considers the correlation between video characteristics, available local resources and the resulting visual quality. The proposed QoS distribution scheme performs inter‐node adaptation, dynamically adjusting local loss constraints in response to network conditions in order to satisfy the end‐to‐end loss requirements. An active network‐based simulation shows that using QoS distribution and packet scheduling together increases the probability of meeting end‐to‐end QoS requirements of networked video. Copyright © 2005 John Wiley & Sons, Ltd.     

异构环境下P2P直播流媒体调度算法研究

对节点上行带宽异构环境下的P2P流媒体系统数据块调度算法进行了研究,具体包括系统模型及相关标识,基于带宽感知的数据块调度算法研究和性能评价。通过研究发现,在设计数据块调度算法时充分利用带宽异构性,优先选择高上行带宽的节点,能有效地降低平均块延时。     

基于网络编码的P2P流媒体传输技术

提出了一种基于网络编码的P2P流媒体传输方案,将分层编码后的数据包在基本层和增强层分别进行网络编码后传输,接收节点可根据带宽情况控制发送节点是否发送增强层数据,提高了播放质量和稳定性.仿真试验表明,基于网络编码的传输方案,接收节点的播放质量能够得到提高,当网络中的节点间带宽剧烈变化的情况下,对比提高尤为明显.     

A buffer‐aware fleet‐based cooperative H.264/SVC streaming over vehicular networks

Because of of the characteristics of high mobility, time varying and dynamic topology, how to provide multimedia streaming service for connected vehicles becomes one emerging and popular technical research. The motivation of this paper is to utilize cooperation among neighboring vehicles for video streaming's quality improvement over vehicular networks. In the proposed cooperative streaming scenario, a connected vehicle requests a video stream from the Internet by using its 3G/3.5G interface, which may not have enough bandwidth to receive good quality of video. Thus, the vehicle is suggested to ask neighboring members belonging to the same fleet to download the requested video data by using their 3G/3.5G interfaces. Then, neighboring members should forward video data to the requested vehicle by using another wireless technique, for example, dedicated short range communication (DSRC). Regarding the differentiation between the two access networks, that is, 3G/3.5G network and DSRC network, a buffer‐aware scheduling mechanism based on layered streaming is designed in this paper to adapt to the networking situation of the vehicular networks. Two selection algorithms are proposed to select neighboring vehicles from the fleet. According to our simulation results, the 3G/3.5G‐based selection algorithm is suitable to improve video quality for vehicles at low speeds. On the other hand, the DSRC‐based selection algorithm can get better performance when vehicles move at high speeds or too many data are transmitted among vehicles.Copyright © 2013 John Wiley & Sons, Ltd.     

Software‐defined network‐based prioritization to avoid video freezes in HTTP adaptive streaming

HTTP adaptive streaming (HAS) is becoming the de facto standard for video streaming services over the Internet. In HAS, each video is segmented and stored in different qualities. Rate adaptation heuristics, deployed at the client, allow the most appropriate quality level to be dynamically requested, based on the current network conditions. It has been shown that state‐of‐the‐art heuristics perform suboptimal when sudden bandwidth drops occur, therefore leading to freezes in the video playout, the main factor influencing users' quality of experience (QoE). This issue is aggravated in case of live events, where the client‐side buffer has to be kept as small as possible in order to reduce the playout delay between the user and the live signal. In this article, we propose a framework capable of increasing the QoE of HAS clients by reducing video freezes. The framework is based on OpenFlow, a widely adopted protocol to implement the software‐defined networking principle. An OpenFlow controller is in charge of introducing prioritized delivery of HAS segments, based on the network conditions and the HAS clients' status. Particularly, the HAS clients' status is obtained without any explicit clients‐to‐controller communication, and thus, no extra signaling is introduced into the network. Moreover, this OpenFlow controller is transparent to the quality decision process of the clients, as it assists the delivery of the segments, but it does not determine the actual quality to be requested. In order to provide a comprehensive analysis of the proposed approach, we investigate the performance of the proposed OpenFlow‐based framework in the presence of realistic Internet cross‐traffic. Particularly, we model two types of applications, namely, HTTP web browsing and progressive download video streaming, which currently represent the majority of Internet traffic together with HAS. By evaluating this novel approach through emulation in several multi‐client scenarios, we show how the proposed approach can reduce freeze time for the HAS clients due to network congestion up to 10 times compared with state‐of‐the‐art heuristics, without impacting the performance of the cross‐traffic applications. Copyright © 2016 John Wiley & Sons, Ltd.     

Visual‐Attention‐Aware Progressive RoI Trick Mode Streaming in Interactive Panoramic Video Service

In the near future, traditional narrow and fixed viewpoint video services will be replaced by high‐quality panorama video services. This paper proposes a visual‐attention‐aware progressive region of interest (RoI) trick mode streaming service (VA‐PRTS) that prioritizes video data to transmit according to the visual attention and transmits prioritized video data progressively. VA‐PRTS enables the receiver to speed up the time to display without degrading the perceptual quality. For the proposed VA‐PRTS, this paper defines a cutoff visual attention metric algorithm to determine the quality of the encoded video slice based on the capability of visual attention and the progressive streaming method based on the priority of RoI video data. Compared to conventional methods, VA‐PRTS increases the bitrate saving by over 57% and decreases the interactive delay by over 66%, while maintaining a level of perceptual video quality. The experiment results show that the proposed VA‐PRTS improves the quality of the viewer experience for interactive panoramic video streaming services. The development results show that the VA‐PRTS has highly practical real‐field feasibility.