發(fā)布時間：2018-04-15 17:50

  本文選題：無線Mesh網(wǎng)絡 + P2P　； 參考：《北京交通大學》2014年博士論文

【摘要】：隨著互聯(lián)網(wǎng)的發(fā)展,流媒體業(yè)務逐漸增多。視頻點播、網(wǎng)絡電視、遠程會議、遠程教育已成為互聯(lián)網(wǎng)的熱門應用。P2P (Peer to Peer,對等端到對等端)技術(shù)的產(chǎn)生使互聯(lián)網(wǎng)的工作模式從以客戶端/服務器為代表的集中式走向了分布式,為流媒體應用帶來了新的發(fā)展空間。與此同時,無線Mesh網(wǎng)絡(Wireless Mesh Networks, WMN)和移動通信設(shè)備的飛速發(fā)展使得人們對P2P流媒體業(yè)務的需求由有線網(wǎng)絡轉(zhuǎn)移到了無線網(wǎng)絡。這種用戶需求推動了基于WMN的P2P流媒體技術(shù)的發(fā)展,而WMN的廣泛應用前景也吸引了P2P流媒體技術(shù)向無線網(wǎng)絡的移植。 基于WMN的P2P流媒體系統(tǒng)是P2P流媒體在WMN支撐下的應用層實現(xiàn),由于WMN網(wǎng)絡的特殊性,P2P技術(shù)在WMN中面臨著許多挑戰(zhàn)與問題。例如,由于無線網(wǎng)絡終端種類繁多造成的網(wǎng)絡異構(gòu)性問題、P2P覆蓋層網(wǎng)絡與底層網(wǎng)絡的拓撲不匹配問題、無線網(wǎng)絡鏈路干擾問題、無線頻譜資源有限問題和缺少系統(tǒng)級實驗平臺的問題。 針對上述研究背景和P2P流媒體技術(shù)在WMN環(huán)境中遇到的問題,本論文在傳統(tǒng)的有線網(wǎng)絡P2P流媒體組播技術(shù)的基礎(chǔ)上,從理論和實驗兩個方面對WMN中的P2P流媒體組播技術(shù)進行了研究。論文的主要研究內(nèi)容和創(chuàng)新點包括： (1)針對覆蓋層網(wǎng)絡與底層網(wǎng)絡的拓撲不匹配問題和無線網(wǎng)絡節(jié)點異構(gòu)性問題,提出了一種無線網(wǎng)絡通用的應用層組播成員管理協(xié)議。該協(xié)議通過采用“閑談”機制、局部概率擇優(yōu)策略和去中心化管理策略,構(gòu)造了一個穩(wěn)定的、無標度的覆蓋層網(wǎng)絡,實現(xiàn)了組播組成員的動態(tài)加入與退出管理。基于復雜網(wǎng)絡理論對所提協(xié)議進行的數(shù)學分析證明了其構(gòu)造的覆蓋層網(wǎng)絡是穩(wěn)定的。仿真結(jié)果表明,所提出的協(xié)議在一定程度上能緩解拓撲不匹配問題,而且比已有的協(xié)議模型更能適應異構(gòu)無線網(wǎng)絡環(huán)境。 (2)針對無線鏈路干擾問題,提出了一種低代價最少中繼樹組播路由算法。該算法由組播樹構(gòu)造算法和信道分配算法兩部分組成。組播樹構(gòu)造算法在保證中繼節(jié)點數(shù)目最少的同時盡量選擇低代價路徑進行數(shù)據(jù)轉(zhuǎn)發(fā),從而充分利用無線鏈路的一跳廣播屬性并且降低了端到端時延。信道分配算法通過擴大干擾優(yōu)化范圍、引入更精確的衡量干擾的參數(shù),優(yōu)化了已有的信道分配算法,從而減少了鏈路干擾。算法分析和仿真結(jié)果表明,所提出的低代價最少中繼樹組播路由算法降低了已有組播樹算法的時間復雜度和組播樹代價,減少了用戶時延,提高了系統(tǒng)吞吐量。 (3)針對無線頻譜資源有限和客戶端資源受限問題,提出了一種基于SNR(Signal Noise Ratio,信噪比)反饋的多信道組播調(diào)度機制。該機制通過SNR反饋判斷信道容量的大小,采用將優(yōu)先級較高的數(shù)據(jù)塊放在信道容量較大的信道上進行傳輸?shù)牟呗?減小了流媒體啟動時延和下載時間,提高了信道利用率。仿真結(jié)果表明,所提出的調(diào)度機制與原有調(diào)度機制相比,在用戶時延、下載時間和帶寬利用率方面的性能都有所提高,但其耗費的緩存空間略大于原有調(diào)度機制。經(jīng)分析,在硬件技術(shù)日趨發(fā)達的今天,存儲空間的獲取對用戶來講并不困難。而在存儲空間充足的條件下,用戶對時間的敏感度明顯高于對空間的敏感度,因此用少量空間換取時間的做法是可取的。 (4)針對缺少系統(tǒng)實驗平臺的問題,實際搭建了基于WMN的P2P流媒體系統(tǒng)。為了客觀和精確地評估WMN中的P2P流媒體性能,啟發(fā)與流媒體性能相關(guān)的下一步研究,在搭建的系統(tǒng)平臺上通過現(xiàn)場實驗的方式測試了流媒體編解碼方式、編碼速率、P2P方式的采用與否、跳數(shù)和網(wǎng)絡拓撲結(jié)構(gòu)五個因素對流媒體性能的影響。實驗結(jié)果表明,編碼方式、編碼速率和網(wǎng)絡拓撲都是影響視頻質(zhì)量的重要因素;跳數(shù)與視頻質(zhì)量沒有必然的聯(lián)系；P2P技術(shù)與WMN結(jié)合是可行的,但是采用P2P方式對WMN中流媒體質(zhì)量的影響有利有弊。實驗結(jié)果對今后的理論創(chuàng)新和實踐部署都具有很好的參考意義。
[Abstract]:With the development of the Internet, streaming media business gradually increased. VOD, IPTV, teleconferencing, remote education has become a popular Internet application.P2P (Peer to Peer, peer to peer) technology makes the Internet work mode from client / server on behalf of the centralized to distributed, bring the new space for the development of streaming media application. At the same time, the wireless Mesh network (Wireless Mesh Networks, WMN) and the rapid development of mobile communication devices for people to make P2P streaming media business needs by wired network to wireless network. The user needs to promote the development of WMN P2P based on streaming media technology, and extensive the application prospect of WMN has also attracted the P2P streaming media technology to the wireless network transfer.
WMN P2P streaming media system is the realization of the application layer of P2P streaming media based on WMN support, because of the particularity of the WMN network, P2P technology faces many challenges and problems in WMN. For example, due to a wide variety of heterogeneous wireless network terminal network problems caused by the P2P overlay network and the underlying network topology does not match the problem, link interference in wireless network, wireless spectrum resources are limited and lack of experimental platform.
Based on the above research background and P2P streaming media technology in the WMN environment encountered problems, this paper based Streaming Media Multicast in wired network P2P on the traditional studies from two aspects of theory and experiment on WMN P2P Streaming Media Multicast Technology. The main research contents and innovations include:
(1) according to the topology of overlay network and the underlying network, and wireless network node heterogeneity problem, proposed application layer multicast membership management protocol for wireless network. This protocol by using the universal "chat" mechanism, the local probability selection strategy and decentralized management strategy, construct a stable, scale-free overlay network, realizes dynamic multicast group members to join and exit management. The mathematical analysis of the proposed protocol for complex network theory proved that the structure of the overlay network is based on stable. The simulation results show that the proposed protocol can alleviate the topology mismatch problem in a certain extent, but can adapt to the heterogeneous wireless network environment than the existing protocol model.
(2) for the wireless link interference problem, proposes a low cost minimum relay tree multicast routing algorithm. The algorithm consists of the multicast tree construction algorithm and channel allocation algorithm is composed of two parts. The multicast tree construction algorithm to ensure the minimum number of relay nodes and low cost path to forward data as far as possible, so as to make full use of. The broadcast property of wireless link and reduce the end-to-end delay. The channel allocation algorithm by expanding the range of interference optimization parameters to measure the interference introduced, more precisely, to optimize the channel allocation algorithms, thereby reducing the link interference. Algorithm analysis and simulation results show that the low cost of the proposed minimum relay tree multicast routing algorithm to reduce the existing multicast tree algorithm time complexity and the cost of the multicast tree, reduce user delay, improve the system throughput.
(3) according to the limited radio spectrum resource and client resource constrained problem, an algorithm based on SNR (Signal Noise Ratio, SNR) multi channel multicast scheduling mechanism. The feedback mechanism by SNR decision feedback channel capacity size, the transmission of higher priority data blocks on the channel capacity of the the strategy reduces the startup delay of streaming media and download time, improve the utilization rate of channel. The simulation results show that the proposed scheduling mechanism compared with the original scheduling mechanism, the user delay, download time and rate the performance of wide band are increased, but the cost of cache space is slightly larger than the original scheduling mechanism. After analysis, the hardware technology increasingly developed today, the storage space of the acquisition is not difficult for users. In adequate storage conditions, users of time sensitivity was significantly higher than that of It is advisable to exchange a small amount of space for time by a small amount of space.
(4) for the lack of experimental platform system, set up WMN based P2P stream media system. In order to objectively and accurately evaluate the performance of WMN P2P streaming media, streaming media and related inspiration performance the next step of the research, through field experiments in the system platform of the streaming media codec the test, encoding rate, and whether the adoption of P2P, effect of jump five factors of streaming media performance and network topology. Experimental results show that the encoding method, encoding rate and network topology are important factors that influence the quality of video; jump no connection number and video quality; P2P technology combined with WMN it is feasible to adopt P2P mode, but the effect on WMN streaming media There are both advantages and disadvantages. quality. The experimental results have a good reference value for the future of theoretical innovation and practical deployment.

【學位授予單位】：北京交通大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TP393.02

【參考文獻】

相關(guān)期刊論文 前10條

1 熊朝松;胡小強;;對等網(wǎng)應用層組播技術(shù)[J];長春理工大學學報(自然科學版);2007年03期

2 劉支援;;無線網(wǎng)狀網(wǎng)在城軌交通中的應用[J];信息化研究;2010年09期

3 劉姝,李偉生,王濤;一種改進的多播路由算法[J];電子與信息學報;2005年04期

4 王璐;李愛玲;;無線Ad Hoc網(wǎng)絡Steiner樹實現(xiàn)協(xié)議研究[J];電子器件;2012年04期

5 張惟曉,黃藝,余兆明;結(jié)合H.263與SLCCA的新的極低比特率小波視頻編碼[J];計算機研究與發(fā)展;2001年05期

6 覃少華;李子木;蔡青松;胡建平;;流媒體點播的服務器通道調(diào)度方案綜述[J];計算機科學;2005年01期

7 劉強;崔莉;陳海明;;物聯(lián)網(wǎng)關(guān)鍵技術(shù)與應用[J];計算機科學;2010年06期

8 楊峰;鄭緯民;余宏亮;曾明;;基于P2P的應用層組播結(jié)構(gòu)研究[J];計算機工程;2007年15期

9 許通;楊壽保;胡云;;基于WMN物理特性的P2P超級節(jié)點選取機制[J];計算機工程;2009年01期

10 王毅;李厚強;孫曉艷;吳楓;劉政凱;;一種針對MPEG-4 AVC/H.264的用于快速碼流生成的運動信息描述算法[J];計算機學報;2007年06期

，

本文編號：1755152