本文選題：P2P　切入點(diǎn)：數(shù)據(jù)調(diào)度　出處：《吉林大學(xué)》2015年碩士論文

【摘要】：隨著互聯(lián)網(wǎng)的高速發(fā)展，超大規(guī)模流媒體應(yīng)用已成為互聯(lián)網(wǎng)和多媒體技術(shù)發(fā)展的趨勢和前沿性方向，對(duì)等網(wǎng)絡(luò)（peer to peer）的出現(xiàn)為大規(guī)模流媒體應(yīng)用提供了技術(shù)支持，P2P流媒體系統(tǒng)以其優(yōu)異的可擴(kuò)展性和易部署等優(yōu)點(diǎn)，迅速占領(lǐng)了市場，但是P2P系統(tǒng)也存在著諸多問題，需要繼續(xù)進(jìn)行研究。 P2P流媒體系統(tǒng)中，參與數(shù)據(jù)傳輸?shù)慕Y(jié)點(diǎn)數(shù)量多，傳輸數(shù)據(jù)量大，而且流媒體數(shù)據(jù)非常注重時(shí)效性，因此必須設(shè)計(jì)合理的數(shù)據(jù)調(diào)度策略，本文對(duì)P2P流媒體系統(tǒng)數(shù)據(jù)調(diào)度的問題進(jìn)行了討論，主要研究內(nèi)容如下： 為了適應(yīng)互聯(lián)網(wǎng)終端帶寬的異構(gòu)性，引入分層視頻編碼的思想，它將原始的視頻流編碼為一個(gè)基礎(chǔ)流和多個(gè)增強(qiáng)流，基礎(chǔ)流保證了最基本的視頻質(zhì)量，，因此需要保證能夠被單獨(dú)解碼，而增強(qiáng)流是為了增加視頻的質(zhì)量，使用戶得到更好觀看享受，用戶根據(jù)自身帶寬情況請(qǐng)求相應(yīng)的視頻層次。建立分層數(shù)據(jù)調(diào)度模型，定義分層數(shù)據(jù)調(diào)度中數(shù)據(jù)塊的優(yōu)先級(jí)，并建立多級(jí)BM（Buffer Map）模型，闡述分層數(shù)據(jù)調(diào)度的基本流程，并通過實(shí)驗(yàn)驗(yàn)證分層數(shù)據(jù)調(diào)度在性能上的優(yōu)越性。 為了將結(jié)點(diǎn)緩沖區(qū)中的數(shù)據(jù)塊進(jìn)行更細(xì)致的劃分，提出了緩沖區(qū)分段的思想，將緩沖區(qū)分為拋棄區(qū)、緊急區(qū)、策略選擇區(qū)、數(shù)據(jù)調(diào)度區(qū)。根據(jù)RTT設(shè)定閾值規(guī)定播放點(diǎn)之后一段區(qū)間內(nèi)的缺失的數(shù)據(jù)塊不再請(qǐng)求以節(jié)省帶寬資源，給出緊急區(qū)邊界的計(jì)算方法，并推導(dǎo)出不同層被選中概率的計(jì)算方法，提出針對(duì)不同的區(qū)段設(shè)計(jì)不同的調(diào)度策略。 分析了P2P系統(tǒng)中數(shù)據(jù)調(diào)度的問題，將數(shù)據(jù)調(diào)度問題形式化，分析了最優(yōu)數(shù)據(jù)調(diào)度的形式，通過理論分析將最優(yōu)調(diào)度問題轉(zhuǎn)化為等價(jià)的可在二項(xiàng)式時(shí)間內(nèi)計(jì)算的最小費(fèi)用流問題，通過推理證明驗(yàn)證了最優(yōu)數(shù)據(jù)調(diào)度問題與最小費(fèi)用流問題求解的一致性，驗(yàn)證了觀點(diǎn)的正確性和可行性。 使用P2P仿真軟件對(duì)上述觀點(diǎn)進(jìn)行了實(shí)驗(yàn)驗(yàn)證，通過調(diào)整實(shí)驗(yàn)中的參數(shù)設(shè)定，得出不同條件層次條件下分層視頻調(diào)度的性能差異，并通過實(shí)驗(yàn)驗(yàn)證分段調(diào)度在性能上優(yōu)于傳統(tǒng)的調(diào)度算法，通過使用Goldberg的“CS2”庫模擬實(shí)驗(yàn)驗(yàn)證基于最大流的數(shù)據(jù)調(diào)度算法在性能上也更優(yōu)于傳統(tǒng)的數(shù)據(jù)調(diào)度算法。
[Abstract]:With the rapid development of the Internet, the application of super-large scale streaming media has become the trend and the leading direction of the development of Internet and multimedia technology. Peer-to-Peer (Peer-to-Peer) provides technical support for large-scale streaming media applications. P2P streaming media system has quickly occupied the market because of its excellent scalability and easy deployment, but there are also many problems in P2P systems. Further research is needed. In P2P streaming media system, the number of nodes involved in data transmission is large, the amount of data transmitted is large, and the streaming media data pay great attention to timeliness, so it is necessary to design a reasonable data scheduling strategy. This paper discusses the problem of data scheduling in P2P streaming media system. The main research contents are as follows:. In order to adapt to the heterogeneity of Internet terminal bandwidth, the idea of layered video coding is introduced. The original video stream is encoded into one basic stream and multiple enhanced streams, and the basic stream guarantees the most basic video quality. Therefore, it is necessary to ensure that the video can be decoded separately, while the enhanced stream is designed to increase the quality of the video and make the user enjoy the video better. According to the bandwidth of the user, the user requests the corresponding video hierarchy and establishes a hierarchical data scheduling model. The priority of data blocks in hierarchical data scheduling is defined, and a multilevel BM(Buffer Map model is established. The basic flow of hierarchical data scheduling is expounded, and the superiority of hierarchical data scheduling in performance is verified by experiments. In order to divide the data blocks in the node buffer more carefully, the idea of buffer segmentation is put forward. The buffer is divided into jettisoning area, emergency area and policy selection area. Data scheduling area. According to the threshold set by RTT, the missing data blocks in the interval after playing point are not requested to save bandwidth resources, the method of calculating the boundary of emergency area is given, and the method of calculating the selection probability of different layers is deduced. Different scheduling strategies are proposed for different segments. This paper analyzes the problem of data scheduling in P2P system, formalizes the problem of data scheduling, and analyzes the form of optimal data scheduling. The optimal scheduling problem is transformed into an equivalent minimum cost flow problem which can be calculated in binomial time by theoretical analysis. The consistency between the optimal data scheduling problem and the minimum cost flow problem is proved by reasoning. The correctness and feasibility of the view are verified. P2P simulation software is used to verify the above viewpoint. By adjusting the parameters in the experiment, the performance differences of layered video scheduling under different conditions and hierarchies are obtained. The performance of piecewise scheduling is better than that of traditional algorithms, and the performance of the data scheduling algorithm based on maximum flow is better than the traditional data scheduling algorithm by using the "CS2" library of Goldberg to simulate the performance of the algorithm.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TP393.02

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 ;GPSA:A Greedy Pull-based Scheduling Approach for P2P Live Streaming under Heterogeneous Environments[J];中國通信;2010年02期

本文編號(hào)：1697938