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  本文選題：視頻點播 + 移動對等網(wǎng)絡��； 參考：《北京郵電大學》2014年博士論文

【摘要】：在無線移動自組網(wǎng)(Mobile ad hoc Networks, MANETs)中提供基于對等網(wǎng)絡(Peer-to-Peer, P2P)的具有主動性流媒體特性的視頻點播(Video-on-Demand, VoD)服務,以支持大規(guī)模移動用戶主動和交互式的訪問視頻資源,已經(jīng)成為未來移動流媒體服務的關鍵技術之一。然而,在MANETs中部署P2P VoD系統(tǒng)卻面臨著巨大的挑戰(zhàn)：(1)VoD服務允許用戶異步接入和主動變更當前播放內(nèi)容,造成P2P網(wǎng)絡中節(jié)點間邏輯連接抖動程度高,嚴重影響用戶播放的連續(xù)性。(2)現(xiàn)有P2P技術存在組網(wǎng)策略僵化、網(wǎng)絡維護負載高和查詢效率低下的問題,難以滿足移動環(huán)境下對資源高效管理與分發(fā)的要求。(3)現(xiàn)有移動網(wǎng)絡環(huán)境變化感知策略嚴重匱乏,移動節(jié)點不具備自適應動態(tài)網(wǎng)絡環(huán)境的能力,節(jié)點間協(xié)作機制相對靜態(tài),使得網(wǎng)絡中可用視頻資源短缺、資源獲取成本高和分享效率低下。針對以上問題,本文對用戶播放行為感知、視頻資源分發(fā)體系和節(jié)點移動性感知等三個關鍵技術進行了深入研究,取得以下成果： (1)設計了面向可靠性的用戶播放行為感知和預測模型。感知具有主動性和交互式等特性且能夠反映當前和未來用戶對視頻內(nèi)容興趣變化、資源請求和使用抖動程度的用戶播放行為,是主動性流媒體服務研究的認知驅(qū)動源的基礎。本文首先提出了資源需求預測算法,精確預測用戶未來播放內(nèi)容,并預先下載到本地,確保用戶播放連續(xù)性；其次,提出了用戶播放狀態(tài)評估模型,基于歷史播放內(nèi)容評估用戶播放行為的可靠性,確保資源提供者與接收者間邏輯連接穩(wěn)定性。 (2)提出了基于移動對等網(wǎng)絡(Mobile P2P, MP2P)的視頻資源管理和分發(fā)機制。由于移動設備存儲能力相對有限和動態(tài)變化的資源需求對MP2P構建和資源分發(fā)策略產(chǎn)生嚴重影響。本文首先提出了MP2P的組網(wǎng)策略和資源搜索算法,根據(jù)用戶歷史與當前播放內(nèi)容建立基于微社區(qū)的MP2P結(jié)構,利用用戶播放行為預測模型,動態(tài)建立微社區(qū)間邏輯關聯(lián),實現(xiàn)資源快速查找;其次,提出了MP2P的維護策略,通過維護具有可靠播放行為的節(jié)點,以降低維護成本。 (3)設計了基于網(wǎng)絡環(huán)境動態(tài)變化感知的資源分享和協(xié)作獲取機制。移動網(wǎng)絡動態(tài)的拓撲結(jié)構造成連接不可靠、數(shù)據(jù)傳輸性能低下,影響用戶平滑的播放體驗。本文首先設計了基于跨層感知和鄰居協(xié)作的視頻資源分享機制,通過感知一跳鄰居通信質(zhì)量變化,設計了資源獲取代價評估模型,建立以資源為中心的簇結(jié)構,提高移動環(huán)境下資源分享效率和傳輸性能；其次,設計了一跳鄰居移動穩(wěn)定性和通信質(zhì)量評估與預測模型,利用移動穩(wěn)定性高且通信質(zhì)量好的節(jié)點協(xié)助下載預測的播放內(nèi)容,減少節(jié)點移動性和通信質(zhì)量變化對視頻數(shù)據(jù)傳輸?shù)挠绊憽?br/>[Abstract]:In wireless mobile ad hoc Networks, MANETs), video-on-demand (VOD) services with active streaming characteristics based on peer-to-peer (P2P) network are provided to support active and interactive access to video resources by large-scale mobile users. It has become one of the key technologies of mobile streaming media service in the future. However, the deployment of P2P VoD system in MANETs is facing a great challenge. The service allows users to access and actively change the current playback content asynchronously, resulting in a high degree of jitter of logical connections between nodes in P2P networks. The existing P2P technology has some problems such as rigid networking strategy, high network maintenance load and low query efficiency. It is difficult to meet the requirements of efficient resource management and distribution in mobile environment. (3) the existing mobile network environment awareness strategy is seriously lacking, mobile nodes do not have the ability of adaptive dynamic network environment, and the cooperation mechanism between nodes is relatively static. It causes the shortage of available video resources, the high cost of resource acquisition and the low efficiency of sharing. In order to solve the above problems, three key technologies of user playing behavior perception, video resource distribution system and node mobility perception are studied in this paper. The following results are achieved: 1) A reliability-oriented model for user playback behavior perception and prediction is designed. Perception has the characteristics of initiative and interaction, and it can reflect the changes of current and future users' interest in video content, resource request and user playing behavior with jitter degree. It is the basis of cognitive driving source of active streaming media service research. In this paper, we first propose a resource demand prediction algorithm to accurately predict the user's future playback content, and download it to the local area in advance to ensure the continuity of user playback. Secondly, a user playback status evaluation model is proposed. The reliability of user playback behavior is evaluated based on historical playback content to ensure the stability of logical connection between the resource provider and the receiver. A video resource management and distribution mechanism based on Mobile P2P (MP2P) in mobile peer-to-peer networks is proposed. Due to the relatively limited storage capacity of mobile devices and the dynamic changes in resource requirements, MP2P construction and resource distribution strategies are seriously affected. In this paper, we first put forward the strategy of MP2P networking and resource search algorithm. According to the user history and current content, we build a MP2P structure based on microcommunity, and use user playback behavior prediction model to dynamically establish logical association between microcommunities. Secondly, the maintenance strategy of MP2P is proposed to reduce the maintenance cost by maintaining nodes with reliable playback behavior. 3) the mechanism of resource sharing and collaborative acquisition based on dynamic change perception of network environment is designed. The dynamic topology of mobile network results in unreliable connection and low performance of data transmission, which affects the user's smooth playing experience. This paper first designs a mechanism of video resource sharing based on cross-layer awareness and neighbor cooperation. By sensing the quality change of one-hop neighbor communication, a cost evaluation model of resource acquisition is designed, and a resource-centric cluster structure is established. Secondly, a one-hop neighbor mobile stability and communication quality evaluation and prediction model is designed to use the nodes with high mobile stability and good communication quality to help download the predicted playback content. Reduce the influence of node mobility and communication quality change on video data transmission.
【學位授予單位】：北京郵電大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TN929.5

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本文編號：1867508