QoS Control in Streaming Media

In this paper, the QoS(Quality of Service) control in streaming media is discussed, and more attention has been paid on the implementation of Qos control in the streaming media server system of the IP network architecture.

Streaming Media流媒体技术在数字图书馆中应用

数字图书馆建设中面临的多媒体信息处理难题 ,Web多媒体新技术 -流媒体技术 ,使用三种流媒体技术应用解决方案 。

AN EMPIRICAL STUDY ON USER ACCESS TO ENTERTAINMENT STREAMING MEDIA

Due to large size and different popularity for different part of the video, most proxy caches for streaming medias cache only a part of the video. Thus, an accurate understanding on the internal popularity distribution of media objects in streaming applications is very important for the development of efficient cache mechanisms. This letter shows that the internal popularity of popular streaming media obeys a k-transformed Zipf-like distribution through analyzing two 6-month long traces recorded at different streaming video servers of an entertainment video-on-demand provider. This empirical model can be used to design an efficient cach- ing algorithm.

Implementation of Mobile Streaming Media Player Based on BREW

Nowadays mobile streaming service through cell phone is becoming the highlight of new value-added mobile services. Based on the present CDMAlx wireless data network and Binary Runtime Environment for Wireless （BREW） platform, adopting compression technologies of H.264 and QCP, a set of streaming media players are designed and implemented, and the principle, structure, key technologies and performance analysis of this system are introduced. This player works well in practice.

Design and Implementation of a Proxy Caching System for Streaming Media

With the widespread use of streaming media application on the Internet, a significant change in Internet workload will be provoked. Caching is one of the applied techniques for enhancing the scalability of streaming system and reducing the workload of server/network. Aiming at the characteristics of broadband network in community, we propose a popularity-based server-proxy caching strategy for streaming medias, and implement the prototype of streaming proxy caching based on this strategy, using RTSP as control protocol and RTP for content transport. This system can play a role in decreasing server load, reducing the traffic from streaming server to proxy, and improving the start-up latency of the client. Key words streaming server - proxy - cache - streaming media - real time streaming protocol CLC number TP 302 - TP 333 Foundation item: Supported by the National High Technology Development 863 Program of China (2001AA111011).Biography: Tan Jin (1962-), male, Ph. D candidate, research direction: network communications, multimedia technologies, and web caching.

A Caching Strategy for Streaming Media

It is expected that by 2003 continuous media will account for more than 50% of the data available on origin servers, this will provoke a significant change in Internet workload. Due to the high bandwidth requirements and the long-lived nature of digital video, streaming server loads and network bandwidths are proven to be major limiting factors. Aiming at the characteristics of broadband network in residential areas, this paper proposes a popularity-based server-proxy caching strategy for streaming media. According to a streaming media popularity on streaming server and proxy, this strategy caches the content of the streaming media partially or completely. The paper also proposes two formulas that calculate the popularity coefficient of a streaming media on server and proxy, and caching replacement policy. As expected, this strategy decreases the server load, reduces the traffic from streaming server to proxy, and improves client start-up latency.

Research of the Streaming Media System Architecture Based on Net-RAID

In the typical streaming media system, the streaming media server is system bottleneck with the expansion of Internet subscribers. This paper proposes an innovational high performance streaming media system architecture (HPSMS) based on the logical separation of streaming media transport protocol. The system avoids expensive store-and-forward data copies between streaming media server and storage devices, improves the system performance greatly. The system bandwidth continuously increases with the expansion of storage system capacity is the highlight. The performance of the proposed HPSMS is evaluated through a practical prototype implementation.

An ALM Model for Streaming Media Service in P2P-SIP Network

Application layer multicast (ALM) has been widely applied in Internet, as a substitute for IP multicast. However, it causes network load to increase because it adopts unicast in data transmission, which limits the application. In this article, in order to improve the ALM performance in P2P-SIP network, an ALM model was proposed which reduced network load via merging messages in concast mode. Finally network simulations prove that this model has better benefit on single node load and average network load. Therefore, it is suitable for streaming media service in P2P-SIP Network.

An energy-saving scheduling scheme for streaming media storage systems

The rapid growth of streaming media applications on the Internet is proposing higher requirements on energy consumption and I/O performance of the storage systems.However,the optimized I/O requests from different initiators will be mixed disorderly when they are reaching the storage system concurrently,which leads to increasing energy consumption.This paper proposes an energy-saving scheduling scheme based on I/O Stream(ES-IOS).The ES-IOS scheme can take the advantage of the I/O characteristics of streaming media and reorganize the mixed and disordered I/O requests into "streams".Technically,The ES-IOS scheme includes two main points,a priority-based weighted stream scheduling algorithm(PWSS) and a regression-fitting-based popularity prediction algorithm(RFPP).The PWSS algorithm can schedule the I/O streams in weighted queue based on priority to limit energy consumption.The priority of each stream is determined by its popularity.According to the I/O access records over a period,the RFPP algorithm can predict the popularity of each stream via regression fitting.Based on the popularities,the PWSS algorithm assigns more continuous service time to the hot streams and reversely less service time to the cold ones.Trace-driven experiments show that the ES-IOS scheme can reduce the energy consumption by 38%and enhance the I/O throughput by 27%approximately.

PROXY-BASED PATCHING STREAM TRANSMISSION STRATEGY IN MOBILE STREAMING MEDIA SYSTEM

A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strat-egy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.

RESEARCH ON GROUPING STRATEGY OF SIP-BASED STREAMING MEDIA P2P LIVE BROADCAST NETWORK

The rapid development of Internet has led to the explosion of information sharing, and how to supervise the sharing is a main research topic on current Internet. Aiming at the disadvantage that the current Peer-to-Peer (P2P) is hard to manage and control, this paper presents a Session Initial Protocol (SIP)-based P2P network of three-level architecture. SIP middleware is introduced to the middle level of the three-layer architecture. By the connection function of the SIP signaling, the P2P transmission on media-level can be controlled. Using SIP’s register and authentication function, the manage layer can manage the whole P2P network. Based on the aforementioned architecture, this paper investigates the grouping strategy on a live broadcast application in P2P network. Combined with the function of SIP register, the paper works on several grouping strategies, sets up models to manage users by grouping them, presents a weight-based K-means IP address grouping algorithm, and realizes it. The experiment shows that the grouping strategy presented in this paper can solve the problem of group sharing of network resource, and can realize the efficient-sharing, reasonable-distributing of network resource.

A segment version transcoding for client-centric wireless mobile media streaming

An object segment similarity function is taken into account from the continuous media frames to measure the individual streaming profit of certain segment versions of a media object.Therefore,a new segment version-based transcoding(SVT)mechanism is derived for a quality of service(QoS)of client-centric media streaming in wireless mobile networks.The derived function utilizes the fuzzy similarity of certain segment versions of an object.This mechanism provides the effectiveness of reduction of the stream startup latency among segment versions,and the average access of each version.Thus,the proposed segment version transcoding mechanism reduces packet loss which in turn increases streaming performance and throughput.The performance of the partitioned segment versions is simulated and some segment versions are completed.The simulation results show that the proposed mechanism outperforms the other mechanisms in average cache hit ratio and in average startup latency ratio.

Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks

Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks.

二重情境:数字视听文化中的身份构建与认同疏离

数字视听媒介及其文化的发展创造了新的情境,推动用户产生新的媒介实践,但也带来了新的问题和现象,即情境生成逻辑向流媒体用户让渡的转变、情境功能作为交往工具的偏移,以及情境秩序在去公共性过程中权力再结构化的取向。其中隐含着情境之于用户身份构建的二重性:一方面,流媒体用户依据情境构建身份,身份的构建过程进一步激发了情境的创造;另一方面,这些被构建的身份呈现出去情境化的流动趋向,造成了身份与认同的疏离。对此,文章在厘清数字视听文化新情境特征的基础上,阐释流媒体用户基于身份的情境互动过程,以及身份认同疏离的成因及危机。更进一步,文章尝试将新媒介—新情境—新行为的线性模式延展为更具解释力的用户主导循环模式,并提出通过共识的凝聚、公共性的重拾和共同体的重建,推动数字视听文化的良序发展。

移动边缘网络中基于QoE的网络媒体流卸载算法

针对移动边缘计算中新兴网络媒体流业务面临的高时延、高能耗、高带宽、低用户体验质量(QoE)等问题,提出一种基于QoE反馈配置卸载(QFCO)算法。首先,联合考虑预处理和优先级划分,从而最大化网络资源利用率,并为计算任务赋予不同的权重建立资源分配关系;然后,综合考虑截止时间、计算资源、功率和带宽等约束,以任务时延、能耗和精确度加权和为优化目标建立QoE模型,利用拉格朗日乘数法求解。仿真结果表明,相比深度增强学习在线卸载(DROO)算法,所提算法可有效实现资源的整体优化配置,更好地提升用户体验质量。

网络新媒介能否提升个人投资者业绩:来自基金直播的证据

党的二十大报告明确提出“多渠道增加城乡居民财产性收入”的目标。本文基于个人投资者微观调查数据从基金直播的视角探讨了网络新媒介对个人投资业绩的影响及其作用机理。研究发现,观看直播购买基金让投资者更易在基金市场中盈利。机制分析表明,基金直播通过增进金融知识、提高投资分散化程度、形成止盈止损习惯、抑制追逐热点等路径提升个人投资业绩。异质性分析发现,基金直播对业绩的提升作用在老年群体、低月收入、缺乏投资经验以及落后数字金融发展地区等群体中更显著。拓展探讨发现,利用基金直播进行投资应避免过度娱乐化,关注直播内容质量和学习金融知识才是重中之重。本文对引导个人投资者科学化投资,发挥资本市场投资者的财富效应提供了参考依据。

Real与Media流媒体技术比较

通过研究和实例设计，探讨了Ｒｅａｌ流媒体技术和Ｍｅｄｉａ流媒体技术的异同之处，以及在应用当中各自的优缺点。

Darwin Streaming server的研究与应用

分析了Darwin streaming server(DSS)的架构和核心流程;讨论了Darwin streaming server的二次开发接口:module;最后给出了一个用户认证的二次开发模块。

基于Windows Media的网络媒体服务系统的实现

介绍了WindowsMedia系统的体系结构和通信协议 ,构建了采用WindowsMedia技术的网络媒体服务系统 ,详细叙述了系统的连接、配置和技术要点 ,以较低的代价实现了媒体服务系统的应用。