本文關(guān)鍵詞： 視頻流 可靠路徑 視頻傳輸 負(fù)載均衡　出處：《電子科技大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著網(wǎng)絡(luò)速率的不斷提高,在智能手機上各種視頻相關(guān)應(yīng)用不斷出現(xiàn),功能也越來越強大,對視頻流的傳輸質(zhì)量要求也越來越高。為了獲得更高的傳輸質(zhì)量,研究如何更有效地在異構(gòu)網(wǎng)絡(luò)上進(jìn)行視頻流傳輸顯得十分必要。對視頻質(zhì)量的優(yōu)化通常是從視頻編碼的角度進(jìn)行的,而不關(guān)心視頻流數(shù)據(jù)在網(wǎng)絡(luò)中的具體傳輸情況。視頻編碼過后的I幀數(shù)據(jù)對視頻質(zhì)量有較大影響,因此在傳輸過程中保證I幀盡量完整地傳輸能夠最大幅度提高視頻傳輸質(zhì)量。本文提出了RPS算法,用于在有多個約束條件的異構(gòu)網(wǎng)絡(luò)拓?fù)渲姓页鲎羁煽康囊粭l路徑來保證I幀的可靠傳輸。算法主要以丟包率、延遲、數(shù)據(jù)速率三個因素為約束條件進(jìn)行建模,并以丟包率為主要約束條件求解多約束條件最優(yōu)路徑選擇問題。通過實驗驗證了在以丟包率為主要差別的不同路徑上進(jìn)行傳輸?shù)玫降囊曨l質(zhì)量會有較大差別,最大差別達(dá)到路徑丟包率每增加一個百分點,會導(dǎo)致視頻客觀質(zhì)量PSNR值下降最高約10dB。在當(dāng)前復(fù)雜的網(wǎng)絡(luò)拓?fù)渲型梢哉业蕉鄺l較可靠的路徑。為了均衡地使用可靠路徑更有效傳輸視頻流數(shù)據(jù),本文提出了IFPWRR算法。算法通過對視頻流數(shù)據(jù)的幀類型加以區(qū)分,并按照I幀優(yōu)先和每幀首數(shù)據(jù)包優(yōu)先的原則,將數(shù)據(jù)包按丟包率加權(quán)分配到多條可靠路徑上優(yōu)化傳輸,保障視頻解碼過程中最重要的數(shù)據(jù)能夠得到最完整地傳輸,同時也兼顧到了各路徑上的負(fù)載均衡,并最終提高視頻流傳輸質(zhì)量。然后通過在三條不同質(zhì)量的可靠路徑上進(jìn)行實驗對比,證明IFPWRR算法比傳統(tǒng)的輪循算法、配額算法更能提高視頻的總體傳輸質(zhì)量,幅度相比最高達(dá)20%。最后,本文結(jié)合RPS算法和IFPWRR算法設(shè)計并實現(xiàn)了一個基于ns-3的仿真系統(tǒng),該系統(tǒng)能夠在多個角度展現(xiàn)視頻流在異構(gòu)網(wǎng)絡(luò)中的具體傳輸細(xì)節(jié)。
[Abstract]:With the improvement of network rate, various video related applications on smart phones are emerging, the functions are becoming more and more powerful, and the quality of video stream transmission is becoming more and more high. It is necessary to study how to transmit video stream more effectively over heterogeneous networks. The optimization of video quality is usually carried out from the point of view of video coding. I frame data after video coding has great influence on video quality. Therefore, in the process of transmission, I frame can be transmitted as completely as possible to improve the video transmission quality. In this paper, RPS algorithm is proposed. This algorithm is used to find the most reliable path in heterogeneous network topology with multiple constraints to guarantee the reliable transmission of I frame. The algorithm is modeled with three constraints: packet loss rate, delay and data rate. With packet loss rate as the main constraint condition, the optimal path selection problem with multiple constraints is solved. The experimental results show that the quality of video transmitted on different paths with packet loss rate as the main difference will be quite different. The biggest difference is that for each increase in the path packet loss rate, The objective quality of video can be reduced by up to 10 dB. More reliable paths can be found in the current complex network topology. In this paper, IFPWRR algorithm is proposed. The algorithm distinguishes the frame types of video stream data, and according to the principle of I frame priority and the first packet priority of each frame, the packets are allocated to multiple reliable paths weighted by packet loss rate. To ensure that the most important data in the video decoding process can be transmitted in the most complete way, and at the same time, the load balance on each path is also taken into account. Finally, the transmission quality of video stream is improved. Then, by comparing three reliable paths with different quality, it is proved that IFPWRR algorithm can improve the overall quality of video transmission better than the traditional role-based algorithm, and the quota algorithm can improve the overall quality of video transmission. At last, this paper designs and implements a simulation system based on ns-3 combined with RPS algorithm and IFPWRR algorithm. The system can display the details of video stream transmission in heterogeneous network from many angles.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN919.8

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本文編號：1519688