基于MSCXP的电力多媒体调度系统研究

通过对现有电力调度系统存在的问题分析,针对智能电网背景下电力调度系统的业务特点及需求提出了一种基于多业务与交换平台的电力多媒体调度系统方案。方案包括IP语音调度功能实现、数据功能实现、视频功能实现和与现有调度系统的互通功能实现四个部分,实现了语音、视频及数据通信等功能,大大提高了调度业务的灵活性,对电力调度交换系统发展和软交换技术在电力调度中的应用都具有重要的参考意义。     

VoIP中为提高语音质量所采用的关键技术

VoIP(Voice over IP)即IP电话,是将话音编码、压缩转换成数据包,在IP网络中进行传输的技术。为应对传统电话公司的竞争,IP电话的语音质量成为决定其未来命运的关键因素。该文首先介绍了几个界定QoS的参数和目前评价IP电话业务语音质量的三种模型：MOS模型、PSQM模型、E模型,然后重点介绍了在终端和网络上提高VoIP语音质量所采用的一些关键技术,应用于终端的技术中比较重要的是语音的编码与压缩、差错控制等,而应用于网络的技术则是解决IP QoS的两种基本模型：综合业务模型和区分业务模型。     

基于宽带接入的IP电话语音终端设计与实现

本文介绍了IP电话的基本功能、特点,并给出了一个基于宽带接入Phone to Phone技术基础而开发的IP电话语音终端系统的硬软件设计.该设计方案改善了传统IP电话语音滞后严重的问题,同时利用已有的硬件建设实现,从而费用低廉,具有良好的应用前景.     

基于PDA的SIP穿越NAT的设计与实现

SIP是IETF提出的IP电话信令协议,广泛应用于数据、语音、视频等多媒体通信业务中。但网络中大量NAT的存在,限制了其在广域网上的应用和发展。本文设计并实现了一种基于STUN协议的NAT穿越方案。该方案目前已成功应用于基于PDA的无线VOIP网络中,并可推广到其它基于SIP协议的终端上,为VOIP业务的推广应用扫清了障碍。     

音乐快递平台中IVR子系统的设计与实现

语音IVR业务融合了语音和短信的互动参与形式,实现了交互式灵活计费,为运营商及SP带来了可观的收入和利润,是现在最常见的语音增值业务的方式之一.着重介绍作为音乐快递平台用户语音接口的IVR业务子系统,该系统可以完成IP网络与电话网的接入,根据用户按键选择完成相应的业务功能,并具有结构灵活、易于业务扩展、高运行稳定性和易于维护的特点.介绍了该系统的网络结构、功能、设备实现方法和软件实现,同时说明了该系统在整个音乐下载平台中的位置及功用.     

音乐快递平台中IVR子系统的设计与实现

语音IVR业务融合了语音和短信的互动参与形式,实现了交互式灵活计费,为运营商及SP带来了可观的收入和利润,是现在最常见的语音增值业务的方式之一。着重介绍作为音乐快递平台用户语音接口的IVR业务子系统,该系统可以完成IP网络与电话网的接入,根据用户按键选择完成相应的业务功能,并具有结构灵活、易于业务扩展、高运行稳定性和易于维护的特点。介绍了该系统的网络结构、功能、设备实现方法和软件实现,同时说明了该系统在整个音乐下载平台中的位置及功用。     

一种宽带流媒体软件终端的设计和实现

提出了一种运行在IP宽带网、基于DirectShow技术、支持IPTV直播业务和VOD点播业务、在PC平台下的宽带流媒体软件终端。着重于整个软件终端系统的构架、各功能模块的功能设计、以及MPEG-2解码中的关键技术。     

构建基于VxWorks平台的嵌入式语音网关

语音网关是实现PSTN(公用电话交换网)与IP网之间通信的关键设备,该文提出了一个基于VxWorks平台的嵌入式语音网关解决方案。在介绍实时操作系统VxWorks及嵌入式微处理器MPC860T的基础上,给出了语音网关的软硬件实现方法。该语音网关能够有效降低语音延迟,提高语音传输质量。     

软交换和IMS关系

IMS(IP Multimedia Subsystem)是IP多媒体系统,是一种全新的多媒体业务形式,它能够满足现在的终端客户更新颖、更多样化多媒体业务的需求.IMS能够解决移网与固网融合,引入语音、数据、视频三重融合等差异化业务的重要方式.软交换是一种基于公共的分组承载网络,呼叫控制与承载相分离,业务控制与呼叫控制相分离,能够承载语音、数据和多媒体等多种业务的一种交换技术.软交换和IMS都是属于NGN的业务网.软交换从设备的实现可以平滑到IMS.逐渐形成IMS+软交换的网络架构.     

IP业务流量及带宽需求预测计算方法在工程实践中的应用

基于IP网络承载数据、语音、视频、无线等多种业务已成为网络发展的趋势。NGN语音、IPTV、三网融合等业务的开展,对承载网络的带宽、质量、可靠性提出了更高的需求,本文例举了在工程实践中某城市IP业务流量及带宽需求预测的计算方法的应用详解。     

Optimal IP-based content provision model for digital content platforms

To increase the provision of digital content based on a pre-existing intellectual property (IP-based content), digital content platforms can either procure finished IP-based content made by IP holders (the IP-holder-led provision model) or develop IP-based content themselves after obtaining adaptation licenses from IP holders (the platform-led provision model). This study develops a stylized analytical model and finds that the platform's choice of provision model is determined by maximum demand, cost efficiency, and the difference in the capacity to generate content-derived revenue between the platform and the IP holder. We also examine the conditions under which a win-win-win outcome for the platform, the IP holder, and consumers can arise.     

基于ICE方式的语音通信原理研究与应用

基于IP的语音通信在复杂的网络环境中,最大的一个困难就是如何穿越各种各样的NAT。目前比较常见的解决方案有STUN、TURN、Proxy等,但是它们在兼容性以及通用性上都有很大的局限。本文探讨了基于ICE方式的语音通信原理,在即时通信系统上实现了基于ICE方式的语音通信模块,测试了多种网络环境下的通话情况。     

VoIP在智能小区对讲系统中的设计与实现

本文介绍了一种基于IP的智能小区对讲系统,是国内首次将VoIP技术应用在智能小区领域。该系统由门口机、用户机和管理机构成,之间用以太网相连接。语音信号进行数字化、压缩处理后转换为IP数据包在IP网络上进行传输,是一个全双工的实时语音传输与处理系。文章分别介绍了该系统的硬件结构和软件实现方法。     

适应多媒体通信的网络集成服务研究

随着Ｉｎｔｅｒｎｅｔ在全球范围内的广泛应用,基于ＩＰ的分组交换网络技术对计算机网络的发展产生了重大的影响。但鉴于它原先设计思想的制约,使得它在为实时语音和图象传输提供服务方面有很大的局限性。文章通过比较电信网络和计算机网络在面向多媒体通信方面作出的努力,提出了基于资源预留的网络集成服务的基本技术框架,以适应多媒体通信,并简要介绍了相关的研究。     

Call admission control and load balancing for voice over IP

IP networks are traditionally designed to support a best-effort service, with no guarantees on the reliable and timely delivery of packets. With the migration of real-time applications such as voice onto IP-based platforms, the existing IP network capabilities become inadequate to provide the quality-of-service (QoS) levels that the end-users are accustomed to. While new protocols such as DiffServ and MPLS allow some amount of traffic prioritization, guaranteed QoS requires call admission control. This paper reviews several possible implementations and shows simulation results for one promising method that makes efficient use of the network and is scalable to large networks.     

一种在蜂窝链路上高效传输实时IP业务的机制

针对在传输信道带宽有限和传输误码率高的蜂窝移动通信系统中,传输基于IP包交换的话音等实时业务时所面临的协议报头开销大、有用包被丢弃等问题,提出一种ROHC/UDP Lite机制,将ROHC报头压缩算法和UDP Lite传输协议有机结合,以解决上述问题.给出了实验模型,分析了实验结果,表明未来的全IP蜂窝移动通信系统采用此机制,能够高效传输基于IP包交换的话音业务.     

Dynamic IP configuration of terminals in broadcasting networks

The concept of synergy between broadcasting and telecommunication networks has been strengthened by the emergence of multi-modal terminals, which are used in a broadcast environment (mainly in DTV-Digital Television networks) to provide IP-based multimedia services. The migration of IPv4/IPv6 applications, either interactive or not, in a broadcasting network, requires that certain parameters, such as Host, Gateway and DNS IP addresses are configured in the terminals, either statically or dynamically. This paper discusses issues of dynamic configuration of IP parameters for DTV terminals, based on an overview of relevant mechanisms usually used in access networks. It proposes an IP-based auto-configuration protocol tailored to the needs of an IP/DTV access platform, describes its implementation and evaluates its behaviour in a laboratory-based DVB-T network.     

基于VoiceXML的语音增值业务平台的架构设计

目前语音增值业务发展迅速，但还缺乏统一的规范。该文设计了一个基于VoiceXML(Voice Extensible Markup Language)的语音增值业务平台的架构，规范了语音增值业务的开发、管理界面，讨论了语音增值业务执行平台和语音增值业务管理平台的功能和结构，着重分析了在此架构上实现业务的几个关键流程，并将此架构和目前IVR(Interactive Voice Response)平台进行了比较。     

Strategies to Keep Your VoIP Network Secure

As VoIP technology matures, more IT departments have made the jump to integrate VoIP into their enterprise communication systems. But, before an organization fully commits to the technology, it should perform a risk assessment, paying close attention to any security measures needed to protect these IP-based voice networks. For telephone systems where controlled access throughout the communications infrastructure isn't necessary, services that leverage machines on the public Internet could be a cost-effective choice. However, for systems where secured network control is critical, VoIP networks based on private enterprise infrastructures should be considered. This article focuses on the security measures associated with private-enterprise-based VoIP networks.     

A multimedia healthcare data sharing approach through cloud-based body area network

Wireless Body Area Network (WBAN), as a dramatic platform for pervasive computing and communication, has been widely applied in healthcare domains. Since the patient-related data in the form of text, image, voice, etc. is significant in the process of healthcare services, efficiently managing these media data from various WBAN is vital for various applications. Recently, Cloud-assisted WBAN has become popular that can supply massive computing, flexible storage and various software services to WBAN. Still, there are some challenging issues exist in this platform to deliver and share the huge media healthcare data to remote terminals timely with guaranteed QoS support. In the paper, we propose an efficient network model that combines WBAN and Cloud for valid data sharing. The proposed network architecture is designed as four layers: perception layer, network layer, cloud computing layer, and application layer. In the network, the integration of TCP/IP and Zigbee in the coordinator devices is utilized. Consequently, WBAN coordinators can compatibility inter-operate with various local networks such as WiFi and LTE network to support high mobility of users. Besides, we integrate Content Centric Networking (CCN) with our proposed architecture to improve the ability of the WBAN coordinator. Thus, it can support uninterrupted media healthcare content delivery. In addition, adaptive streaming technique was also utilized to reduce packet loss. Various simulations were conducted using OPNET simulator to show the feasibility of the proposed architecture in terms of transmitting a huge amount of media healthcare data in real-time under traditional IP-based network.