基于NGOD架构的VOD流媒体服务器会话处理方案

主要介绍了一种基于NGOD架构的数字电视视频点播系统的流媒体服务器会话处理方案。通过在视频点播系统中使用有效的流媒体服务器(Streaming-Server)会话并发处理方案,有效地增强了会话处理的速度和能力,从而提高了推流的能力,让VOD系统有更好的用户体验。     

面向P2P流媒体的双栈服务器设计与实现

在流媒体直播系统应用背景下,提出了一种基于IPv6且兼容IPv4N络的双栈Tracker）服务器的设计与实现方案;并介绍采用SIP（会话初始协议）进行流媒体用户、流媒体服务器与．Tracker服务器之间会话的发起、建立连接与释放过程;最后分析了双栈服务器的优势和在流媒体直播系统中的应用前景。     

基于NGOD架构的VOD系统边缘资源会话管理方案

介绍了一种基于下一代视频点播NGOD架构的数字电视视频点播系统的边缘资源的会话管理方案。通过在视频点播系统中引用边缘资源管理器ERM,有效降低了带宽资源的无谓消耗,使边缘设备资源得以有效利用,能更好地处理用户请求。     

基于流媒体的小型分布式视频点播系统研究

针对视频点播系统中存在的高带宽、高存储、低并发性等问题,提出了一种基于流媒体的小型分布式的视频点播系统,通过把视频进行分段并动态分布到不同的服务器实现了分布式存储.通过文件共享机制并在数据库中纪录和维护视频信息实现对不同视频服务器上视频资料的统一管理.仿真测试结果表明,该方案能大大提高视频点播系统的并发访问量,并可动态添加视频服务器以满足日益增长的视频点播需求.     

基于Windows Media平台的视频点播系统方案设计

很多企事业单位内部局域网中都有视频点播的功能需求。文章分析比较了目前常用流媒体相关技术,针对企事业单位局域网这一具体的应用环境,提出了以流媒体服务器、Web服务器、视频文件压缩编码,以及支持组播的网络四个模块为主体的视频点播系统,为企事业单位提供了视频点播的方案设计。     

挛托罗拉推出B-3视频服务器拓展视频点播平台

摩托罗拉公司今日推出了摩托罗拉B-3视频服务器。该产品的推出拓展了摩托罗拉的视频点播平台,打造出业内覆盖范围最广、最灵活的固态点播服务器产品组合。摩托罗拉B-3视频服务器作为世界最广泛部署的固态点播服务器摩托罗拉B-1的一个补充,专为中小规模流媒体站点提供服务。通过结合使用摩托罗拉的CPS1000内容分发系统,摩托罗拉的视频点播平台能够支持快速增长的视频点播需求以及大型内容库,同时帮助运营商优化存储、流媒体和网络资源。     

算通高标清TS流播出系统中标广西

摩托罗拉公司近日推出了摩托罗拉B-3视频服务器。该产品的推出拓展了摩托罗拉的视频点播平台,打造出业内覆盖范围最广、最灵活的固态点播服务器产品组合。摩托罗拉B-3视频服务器作为世界最广泛部署的固态点播服务器摩托罗拉B-1的一个补充,专为中小规模流媒体站点提供服务。通过结合使用摩托罗拉的CPS1000内容分发系统,摩托罗拉的视频点播平台能够支持快速增长的视频点播需求以及大型内容库,同时帮助运营商优化存储、流媒体和网络资源。     

摩托罗拉拓展视频点播平台支持内容节目库的迅速增长需求

肇托罗拉公司目前推出了摩托罗拉B-3视频服务器。该产品的推出拓展了摩托罗拉的视频点播平台．打造出业内覆盖范围最广、最灵活的固态点播服务器产品组合。摩托罗拉B-3视频服务器作为世界最广泛部署的固态点播服务器摩托罗拉B-1的一个补充,专为中小规模流媒体站点提供服务。通过结合使用摩托罗拉的CPS1000内容分发系统．摩托罗拉的视频点播平台能够支持快速增长的视频点播需求以及大型内容库,同时帮助运营商优化存储、流媒体和网络资源。     

基于RTSP协议的视频点播系统设计

介绍了RTSP流媒体协议的体系结构和工作原理。利用RTSP协议阐述了视频点播系统的服务器和客户端设计原理。并且以LiveNetworks公司提供的开源代码live库为基础,给出了嵌入式Linux平台下流媒体点播系统的开发实例及其测试方法和测试结果,为视频点播系统的开发提供参考。     

移动流媒体服务器系统关键技术分析

首先分析了移动流媒体服务器系统的整体架构,然后对其中需要解决的关键技术进行了分析,包括：移动流媒体传输的QoS保证,移动流媒体传输控制会话协议,移动流媒体代理服务器,移动流媒体服务器存储调度策略。     

一种基于ARM处理器的异常处理设计与实现

嵌入式系统要求对异常及中断处理器能快速响应。文中分析了ARM体系结构下异常处理特点,提出一种基于ARM处理器的高效异常处理解决方案,以LPC3250硬件平台为基础,对该方案进行了设计与实现。测试结果表明,该方案的异常处理更为高效。     

中间件在税务信息化中的应用

针对中国税务信息化建设过程中存在的问题,以及对中间件的特点、在税务信息化中应用中间件技术的好处、可行性等的分析,提出了应用中间件CDAP进行解决的思路及一种基于该中间件CDAP的税务信息化系统体系结构,并对其参数进行了适当的优化与调整。不但提高了系统的并发处理能力和效率,而且较好地解决了数据完整性和安全性等问题。     

水泥实验室能力验证信息统计分析系统设计

针对水泥实验室能力验证实施过程中大量的数据处理的需要,设计开发了水泥实验室能力验证信息统计分析系统。该系统采用基于Java语言的Eclipse开发工具和Oracle数据库,使能力验证实施者能快捷精准地处理能力验证的信息数据:对能力验证样品的均匀性做出自动分析评定,能力验证试验结果稳健Z(ZB和ZW)值等结果自动计算处理分析,迅速生成专业汇总表和Z比分数直方图。该系统实现了水泥能力验证实施工作自动化管理、提高了数据信息处理的速度和准确性。     

From IPTV to synchronous shared experiences challenges in design: Distributed media synchronization

Recent developments on Social TV point to an evolution from traditional IPTV services towards more social experiences. Newer applications and services have appeared wherein groups of people in different locations can watch multimedia content while synchronously communicating with each other. We name such applications as synchronous shared experiences. Realization of these shared experiences requires that users feel that they are coherently communicating with each other. This paper identifies and analyzes challenges that need to be tackled to achieve coherence: quality of service, mobility and distributed media synchronization. Furthermore, universal session handling is required to setup these sessions. We then present our solution to one of these challenges: distributed media synchronization. Our design uses the local lag mechanism over a distributed control or master-slave signaling architecture. We validate our implementation via experiments performed with one client located in Amsterdam and the other in Seoul. The experiments demonstrate a bound in play-out skew of 500 ms across these locations. Our results from user tests, presented elsewhere, show that this value is well within tolerance limits.     

A new approach for asynchronous distributed rate control of elasticsessions in integrated packet networks

We develop a new class of asynchronous distributed algorithms for the explicit rate control of elastic sessions in an integrated packet network. Sessions can request for minimum guaranteed rate allocations (e.g., minimum cell rates in the ATM context), and, under this constraint, we seek to allocate the max-min fair rates to the sessions. We capture the integrated network context by permitting the link bandwidths available to elastic sessions to be stochastically time varying. The available capacity of each link is viewed as some statistic of this stochastic process [e.g., a fraction of the mean, or a large deviations-based equivalent service capacity (ESC)]. The ESC is obtained so as to satisfy an overflow probability constraint on the buffer length. For fixed available capacity at each link, we show that the vector of max-min fair rates can be computed from the root of a certain vector equation. A distributed asynchronous stochastic approximation technique is then used to develop a provably convergent distributed algorithm for obtaining the root of the equation, even when the link flows and the available capacities are obtained from on-line measurements. The switch algorithm does not require per connection monitoring, nor does it require per connection marking of control packets. A virtual buffer based approach for on-line estimation of the ESC is utilized. We also propose techniques for handling large variations in the available capacity owing to the arrivals or departures of CBR/VBR sessions. Finally, simulation results are provided to demonstrate the performance of this class of algorithms in the local and wide area network context     

Optimal call admission control on a single link with a GPS scheduler

The problem of call admission control (CAC) is considered for leaky bucket constrained sessions with deterministic service guarantees (zero loss and finite delay bound) served by a generalized processor sharing scheduler at a single node in the presence of best effort traffic. Based on an optimization process, a CAC algorithm capable of determining the (unique) optimal solution is derived. The derived algorithm is also applicable, under a slight modification, in a system where the best effort traffic is absent and is capable of guaranteeing that if it does not find a solution to the CAC problem, then a solution does not exist. The numerical results indicate that the CAC algorithm can achieve a significant improvement on bandwidth utilization as compared to a (deterministic) effective bandwidth-based CAC scheme.     

Search biases in constrained evolutionary optimization

A common approach to constraint handling in evolutionary optimization is to apply a penalty function to bias the search toward a feasible solution. It has been proposed that the subjective setting of various penalty parameters can be avoided using a multiobjective formulation. This paper analyzes and explains in depth why and when the multiobjective approach to constraint handling is expected to work or fail. Furthermore, an improved evolutionary algorithm based on evolution strategies and differential variation is proposed. Extensive experimental studies have been carried out. Our results reveal that the unbiased multiobjective approach to constraint handling may not be as effective as one may have assumed.     

Impersonation attacks on software-only two-factor authentication schemes

Two-factor authentication is favorable to securely identifying remote users in a communications network. Lately cryptographic camouflage was applied for the purpose by software-only techniques. However it can be vulnerable to impersonation attacks via interleaved sessions if a single server is compromised. This article brings to light such a hidden weak point and suggests a possible solution.     

多媒体远程教学系统实时传输解决方案

有效的传输机制是保障多媒体远程教学系统这样的分布式多媒体系统应用需求的关键。针对分布式多媒体应用,结合流媒体的传输控制协议,提出了一种远程教学系统实时传输解决方案:通过RTSP(实时流传输协议)建立和控制多媒体会话,RTP(实时传输协议)承载实时信息的传输,RTCP(实时传输控制协议)监控数据的传输状态,RSVP(资源预留协议)预约传输所需的Internet资源保证服务质量。该传输方案不仅适用于远程教学系统,也适用于其他基于Internet的实时多媒体应用系统。     

基于M估计的多传感器数据稳健加权融合算法仿真

提出M估计与不确定度评定相结合的多传感器数据加权融合方法，克服了现有的数据评价函数加权法中存在的大噪声及成片野值处理能力的局限性。通过静态数据仿真结果，表明基于M估计的多传感器数据稳健加权融合算法明显优于最小二乘法。