Token-based incentive mechanism for peer-to-peer video streaming networks

The Journal of Supercomputing - We consider the problem of live video streaming in peer-to-peer networks consisting of selfish peers aiming at maximizing peers’ individual utilities. We use...     

An incentive scheduling mechanism for peer-to-peer video streaming

P2P video streaming networks are found as a scalable solution and an alternative for traditional client–server based video streaming over the Internet. One of the significant issues affecting the success of any P2P streaming network is cooperation between peers. Practical observations have proved the prevalence of free riders in P2P networks that degrade their performance. To solve this problem, using incentive mechanisms, which encourage peers to contribute more in the network, is necessary. In this paper, we designed and proposed a distributed and scalable incentive mechanism for mesh based P2P video streaming networks. In the proposed approach the contribution of the peers is measured and maintained in a distributed fashion. Furthermore, we proposed an incentive sending side scheduler in which peers are served based on their contribution in the network. Our simulation evaluations show the efficiency of the proposed approach in improving the overall perceived video quality by the non-free rider nodes and consequently in the whole network.     

Service differentiated peer selection: an incentive mechanism for peer-to-peer media streaming

We propose a service differentiated peer selection mechanism for peer-to-peer media streaming systems. The mechanism provides flexibility and choice in peer selection to the contributors of the system, resulting in high quality streaming sessions. Free-riders are given limited options in peer selection,if any, and hence receive low quality streaming. The proposed incentive mechanism follows the characteristics of rank-order tournaments theory that considers only the relative performance of the players, and the top prizes are awarded to the winners of the tournament. Using rank-order tournaments, we analyze the behavior of utility maximizing users. Through simulation and wide-area measurement studies, we verify that the proposed incentive mechanism can provide near optimal streaming quality to the cooperative users until the bottleneck shifts from the streaming sources to the network.     

A survey on peer-to-peer video streaming systems

Video-over-IP applications have recently attracted a large number of users on the Internet. Traditional client-server based video streaming solutions incur expensive bandwidth provision cost on the server. Peer-to-Peer (P2P) networking is a new paradigm to build distributed network applications. Recently, several P2P streaming systems have been deployed to provide live and on-demand video streaming services on the Internet at low server cost. In this paper, we provide a survey on the existing P2P solutions for live and on-demand video streaming. Representative P2P streaming systems, including tree, multi-tree and mesh based systems are introduced. We describe the challenges and solutions of providing live and on-demand video streaming in P2P environment. Open research issues on P2P video streaming are also discussed.

Adaptive multi-view video streaming using side information over peer-to-peer networks

Multimedia Tools and Applications - Multi-view plus-depth-map (MVD) video streaming with autostereoscopic displays provides multi-user immersive media experiences. In this context, delivery of MVD...     

Adaptive topology formation for peer-to-peer video streaming

In this paper we propose an adaptive P2P video streaming framework to address the challenges due to bandwidth heterogeneity and peer churn on the Internet. This adaptive streaming framework consists of two major components, source rate adaptation and adaptive overlay topology formation, to maximize the video quality and fully utilize the overall peer upload capacity. In the source rate adaptation, the video server adapts the video source rate automatically based on the local measurement of peers’ download rates, so that the P2P network is not overloaded beyond its bandwidth capacity and peers are able to achieve smooth video playback. To combat bandwidth heterogeneity, we propose to construct a desirable link-level homogeneous overlay topology using a Markov chain Monte Carlo method, so that peers achieve an equal per-connection upload/download bandwidth. In this link-level homogeneous network, video flows do not encounter any bottlenecks along the delivery paths, and peers achieve high download rates to ensure smooth video playback. We also design a fully distributed algorithm to implement the dual mechanisms of the adaptive topology formation and the source rate maximization. To evaluate the performance of our streaming framework, we conduct both mathematical analysis and extensive simulations. The simulation results confirm our analysis and show that the proposed distributed algorithm is able to maximize the video playback quality with fast convergence.     

一种基于公钥体系的P2P激励机制

针对P2P网络的搭便车行为及网络资源的同质化现象,提出了一个基于PKI体系和结构化P2P网络的激励机制。该激励机制不但鼓励节点提供资源下载,还让资源发布者从中受益,从而有效地抑制搭便车行为,减轻了资源的同质化现象。     

Joint bandwidth allocation,data scheduling and incentives for scalable video streaming over peer-to-peer networks

The overall performance of a peer-to-peer (P2P) scalable streaming system largely depends on the strategies employed in bandwidth allocation, data scheduling and incentives. In this paper, we develop a credit-based content-aware bandwidth auction model for scalable streaming in P2P networks. It formulates multi-overlay multi-layer bandwidth request and allocation problems as auction games. Each peer in the games acts as both auctioneer and player. Being a auctioneer, it maximizes the total revenue (credits) by selling upload bandwidth; Being a player, it uses the credits earned in bandwidth sales to sequentially bid for layer bandwidth so as to maximize the received video quality. Also, a content-aware bidding strategy is proposed, under which the required bandwidth quantity from a peer is determined by the informative video chunks and the marginal net utility that peer could provide, as well as the available credits and the maximum layer bit rate. The convergence of the proposed auction algorithm is mathematically proved. Finally, the performance of the proposed scheme is verified by simulation results.     

Optimum piece selection strategies for a peer-to-peer video streaming platform

The client–server architecture is still popular due to its high predictable service and performance. However, it is not bandwidth scalable. An alternative setup for Internet video-streaming is offered by the peer-to-peer architecture, in which peers are servers as well as clients. Peers basically communicate in a three-level based policy. First, they meet other peers with common interests: this is called swarming. Then, each peer selects a small number of them for cooperation, called the peer selection strategy. In the last step peers cooperate sending pieces, defining the piece selection strategy.     

Effect of node churn on frame interval for peer-to-peer video streaming with data-block synchronization mechanism

Coolstreaming is a mesh based peer-to-peer (P2P) video streaming system in which single video stream is decomposed into multiple sub-streams. A client-peer node retrieves the sub-streams from multiple parent-peer nodes, combining them into the original video stream. Each client-peer node has two buffers, a synchronization buffer and a cache buffer, and arriving data blocks are synchronized at the synchronization buffer and then forwarded to the cache buffer. In this buffering system, data-block synchronization is important to guarantee high video quality. In this paper, we consider the effect of churn on the performance of data-block synchronization scheme with which data blocks are simultaneously forwarded just after all the data blocks composing a macro data block arrive at the synchronization buffer. It is assumed that data blocks belonging to a sub-stream arrive at the client-peer node according to an interrupted Poisson process. The synchronization buffer is modeled as a multiple-buffer queueing system with homogeneous interrupted Poisson processes, and the mean forwarding interval is derived. Numerical examples show that the average forwarding interval increases as parent-peer nodes leave more frequently.     

Packet loss in peer-to-peer video streaming over the Internet

Peer-to-peer streaming has recently gained attention as an effective solution to support large scale media streaming applications over the Internet. One of the main challenges of peer-to-peer video streaming is the cumulative impact of the Internet packet loss due to the decoding dependency of the compressed video frames. In this paper we study the impact of the Internet packet loss on the performance of peer-to-peer video streaming systems, and analyze the efficiency of various packet loss recovery policies in such systems. Our analytical and simulation results show how the Internet packet loss can affect the performance of peer- to-peer video streaming systems and how different packet loss recovery policies can be effective for such systems. Our analysis results give us some insights that can be used in designing efficient peer-to-peer video streaming systems.     

Towards efficient video chunk dissemination in peer-to-peer live streaming

There are substantial differences in chunk dissemination manner between P2P live streaming and BitTorrent, and inappropriate algorithms will result in inefficiency of live streaming systems. In this paper, we study the chunk dissemination of P2P live streaming, and introduce a discrete and slotted mathematical model to analyze chunk selection algorithms, including rarest first algorithm and greedy algorithm. Moreover, we present a performance metric to evaluate chunk selection algorithms, as well as the optimization function for the exploration of chunk dissemination strategies. We point out the causes of poor performance of these algorithms, and propose a service request randomization mechanism to promote the use of peer resources, which can prevent chunk requests from rendezvous on a few of peers. Simultaneously, we employ weight assignment strategies to avoid excessive requests for rare chunks. Besides, we present an enhanced model, which adds node degree constraint, to improve our model. We revisit the chunk selection algorithms based on the enhanced model. The results of simulation experiments validate our theoretical analysis and indicate that the weighted randomization mechanism is resilient to flash crowd and peer churn, and can improve the performance of P2P live streaming.     

Sub-packet forward error correction mechanism for video streaming over wireless networks

Traditional Forward Error Correction (FEC) mechanisms can be divided into Packet level FEC (PFEC) mechanisms and Byte level FEC (BFEC) mechanisms. The PFEC mechanism of recovering from errors in a source packet requires an entire FEC redundant packet even though the error involves a few bit errors. The recovery capability of the BFEC mechanism is only half of the FEC redundancy. Accordingly, an adaptive Sub-Packet FEC (SPFEC) mechanism is proposed in this paper to improve the quality of video streaming data over wireless networks, simultaneously enhancing the recovery performance and reducing the end-to-end delay jitter. The SPFEC mechanism divides a packet into n sub-packets by means of the concept of a virtual packet. The SPFEC mechanism uses a checksum in each sub-packet to identify the position of the error sub-packet. Simulation experiments show the adaptive SPFEC mechanism achieves high recovery performance and low end-to-end delay jitter. The SPFEC mechanism outperforms traditional FEC mechanism in terms of packet loss rate and video Peak Signal-to-Noise Ratio (PSNR). SPFEC offers an alternative for improved efficiency video streaming that will be of interest to the designers of the next generation environments.     

Distributed multi-source streaming models in peer-to-peer overlay networks

A multimedia contents are distributed to peer computers (peers) and a contents peer which holds contents can provide other peers with the contents in peer-to-peer (P2P) overlay networks. Here, contents peers are mainly realized in less-reliable and low-performance personal computers. Multimedia streaming is more significant than downloading ways in multimedia applications from security and economical reasons. We discuss distributed multi-source streaming models to support peers with reliable and scalable multimedia streaming service. Here, a collection of multiple contents peers in parallel transmit packets of a multimedia content to a leaf peer to realize the reliability and scalability. Each of the contents peers send different packets from the other contents peers at slower rate. Even if not only some number of peers stop by fault and are degraded in performance but also some number of packets are lost and delayed in networks, a leaf peer has to receive every data of a content at the required rate. We discuss how to replicate data of a multimedia content by creating a parity packet for some number of packets and to allocate packets to each contents peer so that a leaf peer can deliver a packet without waiting for preceding packets from other contents peers in presence of the faults. Next, multiple contents peers are required to be synchronized to send packets to a leaf-peer so that the leaf-peer can receive every data of a content at the required rate. We discuss a pair of gossip-based flooding-based protocols, directed acyclic graph (DAG)-based coordination protocol (DCoP) and tree-based (TCoP) coordination protocol to synchronize multiple contents peers to send in parallel send to a leaf peer. First, some number of contents peers are selected and start transmitting packets to a leaf peer. Then, each of the selected peers selects some number of peers. Here, a peer can be selected by multiple peers in DCoP but by at most one peer in TCoP. Finally, every contents peer transmits packets to the leaf peer at the allocated rate. We evaluate the coordination protocols DCoP and TCoP in terms of how long it takes and how many messages are transmitted to synchronize multiple contents peers.     

A dependable multisource streaming system for peer-to-peer -based video on demand services provisioning

In this article, we present the design, implementation, and analysis of a scalable VOD (Video On Demand) distribution architecture for IP networks. The focus of our work is on the underlying multisource streaming architecture upon which the P2P (Peer-to-Peer) -based VOD services provisioning system relies. While multipoint-to-point multisource streaming is the core building block for a distributed VOD services provisioning system, it also introduces new reliability challenges as the streaming failure probability increases with the number of sources in a session. A major contribution of our work is the design of a suite of distinct yet complementary reliability/failover mechanisms that can be leveraged to improve the dependability of multisource streaming, and the viability of P2P-based VOD systems in general. Our work shows that the reliability/failover mechanisms can be arranged, combined, and alternated in advanced adaptation policies in order to deal with different conditions exhibited by the network. Another contribution of our work consists of implementing and assessing the performance of the different reliability mechanisms and adaptation policies in a real prototype system. We evaluate both the accuracy of streaming problems diagnosis, and the efficiency of the reliability mechanisms, in two adaptation strategies: one responsive to loss variation, and the other responsive to delay variation.     

An incentive mechanism for message relaying in unstructured peer-to-peer systems

Distributed message relaying is an important function of a peer-to-peer system to discover service providers. Existing search protocols in unstructured peer-to-peer systems create huge burden on communications, cause long response time, or result in unreliable performance. Moreover, with self-interested peers, these systems are vulnerable to the free-riding problem. In this paper we present an incentive mechanism that not only mitigates the free-riding problem, but also achieves good system efficiency in message relaying for peer discovery. In this mechanism promised rewards are passed along the message propagation process. A peer is rewarded if a service provider is found via a relaying path that includes this peer. The mechanism allows peers to rationally trade-off communication efficiency and reliability while maintaining information locality. We provide some analytic insights to the symmetric Nash equilibrium strategies of this game, and an approximate approach to calculate this equilibrium. Experiments show that this incentive mechanism brings a system utility generally higher than breadth-first search and random walks, based on both the estimated utility from our approximate equilibrium and the utility generated from learning in the incentive mechanism.     

A vEB-tree-based architecture for interactive video on demand services in peer-to-peer networks

To provide interactive operations such as random seeking for peer-to-peer on demand video streaming is a challenge. In this paper, a vEB-tree (van Emde Boas tree)-based architecture is proposed for interactive VoD services in peer-to-peer networks. The proposed architecture divides a video into many segments that are distributed among participating peers. In this architecture, it includes a vEB-tree-based topology, searching procedures for demand segments, and a segment distribution scheme. It not only efficiently provides interactive operations but also reduces control messages. Additionally, each peer stores segments based on the proposed segment distribution scheme to reduce server stress. Experimental results demonstrate that the proposed architecture outperforms other competing architectures in terms of jump latency, server stress, and cost of maintaining searching topology.     

A mechanism for resource pricing and fairness in peer-to-peer networks

In peer-to-peer (P2P) networks, each peer acts as the role of client and server. As a client, each peer is regarded as a service customer. It sends requests to other peers to download files and obtains resource allocation from them. As a server, each peer is thought as a service provider. It receives service requests from other peers and allocates its resources to them. To encourage cooperation between peers, fairness is very important in P2P networks since it fosters an incentive to the peers to offer resources to the network. We formulate a fair resource allocation model for P2P networks and investigate the utility optimization problem by Lagrangian method. In order to realize the optimal resource allocation, we present a novel price-based resource allocation scheme by applying the first order Lagrangian method and low-pass filtering scheme, so that a service provider can allocate its resources to its customers based on offered prices, achieving the efficient and fair allocation of the available resources to the serviced customers. Simulation results confirm that the proposed algorithm can achieve the optimum within reasonable convergence times.     

一种移动网络视频流U-vMOS分类算法

针对传统分类算法无法有效解决高度不平衡移动网络视频流U-vMOS分类问题,提出基于代价敏感(cost-sensitive)思想改进AdaBoost算法构造U-vMOS分类器,在迭代过程中,于样本权重更新环节引人代价敏感因子,增加对少数类(mi-nority)关注,最终 U-vMOS 分类器获得优秀 的查准率和查全率.实验结果表明,在数据非均衡条件下,改进AdaBoost算法F-Measure值和稳定性明显优于其它算法,能够为运营商和视频产业链提升用户体验给出有用的指导建议.