Metadata-driven multimedia access

With the growing ubiquity and mobility of multimedia-enabled devices, universal multimedia access (UMA) is emerging as one of the important components for the next generation of multimedia applications. The basic concept underlying UMA is universal or seamless access to multimedia content, by automatic selection and adaptation of content based on the user's environment. UMA promises an integration of these different perspectives into a new class of content adaptive applications that could allow users to access multimedia content without concern for specific coding formats, terminal capabilities, or network conditions. We discuss methods that support UMA and the tools provided by MPEG-7 to achieve this. We also discuss the inclusion of metadata in JPEG 2000 encoded images. We present these methods in the typical order that they may be used in an actual application. Therefore, we first discuss the (personalized) selection of desired content from all available content, followed by the organization of related variations of a single piece of content. Then, we discuss segmentation and summarization of audio video (AV) content, and finally, transcoding of AV content.     

Project EXODUS: Experimental mobile multimedia deployment in ATM networks

This paper reports on European Commission sponsored research within the EXODUS project. The project carries out research in the context of the evolution towards UMTS and performs personal and terminal multimedia mobility experiments using fixed and wide-band radio access in an international ATM network. After introducing the EXODUS platform and services, the paper presents an IN-based functional model which is suitable for support of mobile multimedia services in ATM networks. Interworking and mobility management issues are discussed, and information flows for call handling are presented. The paper includes a presentation of the mobility management and enhanced INAP protocols which have been developed by the EXODUS project. This revised version was published online in July 2006 with corrections to the Cover Date.     

Interactive multimedia satellite access communications

Recent advances in satellite technology are making possible the development of broadband satellite access (BSA) systems for two-way access to multimedia Internet services. This article provides an overview of BSA systems with an emphasis on resource management and interworking techniques to support IP-based multimedia services. The article draws on collaborative research performed over the past few years as part of the Broadband Satellite Communications Major Project of the Canadian Institute of Telecommunications Research. Some key innovations are described: combined free/demand assigned multiple access (CFDAMA) for dynamic satellite bandwidth allocation; an architecture for DiffServ provisioning over BSA systems; and a dynamic TCP Vegas protocol as a proxy service for split-TCP connections over BSA systems.     

Video delivery technologies for large-scale deployment of multimedia applications

Deployment of a large-scale multimedia streaming application requires an enormous amount of server and network resources. The simplest delivery technique allocates server resources for each specific request. This technique is very expensive and is not scalable to support a very large user community such as the Internet. Hence, the past decade has witnessed tremendous research efforts to facilitate cost-effective, large-scale deployment of multimedia streaming applications. In this paper, we describe three complementary research approaches: server transmission schemes using multicast, streaming strategies with application layer multicast, and proxy caching techniques. We discuss pros and cons of these technologies and provide our observations on current business solutions.     

面向云网融合的传输接入及SDN部署策略研究

云业务是运营商实现政企业务突破的关键入口,大力发展云业务驱使运营商快速提升云网一体化服务能力,提供高品质云专线。本文提出面向云网融合的传输OTN、SPN接入方案及传输网络SDN部署策略,为现阶段基于传送网的云网融合部署提供参考借鉴。     

IP-based access networks for broadband multimedia services

The increasing demands of new services and applications are pushing for drastic changes in the design of access networks for residential and SOHO users. Future access networks will provide full service integration, resource sharing at the packet level, and QoS support. It is expected that using IP as the base technology, the ideal plug-and-play scenario, where the management actions of the access network operator are kept to a minimum, will be achieved easily. In this article we start by giving a historical perspective of the evolution of access networks. We then describe an IP-based architecture targeted for integrated support of broadband multimedia services, designed to be low-cost and easily manageable. We illustrate the different phases of a multimedia Internet access session, when using SIP for session initiation, COPS and DIAMETER for QoS policy management, and AAA and RSVP for resource reservation.     

CM-IMS用户接入设备安全风险分析及部署建议

通过对CM-IMS的用户接入设备的安全风险分析,分析CM-IMS用户接入设备所面临的多种安全风险,及用户接入设备的安全部署需求,并针对需求提出了部署建议.     

EPON无线接入多媒体终端的设计与实现

EPON(以太网无源光网络)作为具有广阔应用前景的光纤接入网技术已经越来越多地应用于接入网系统中.文章提出将WLAN(无线局域网)技术与EPON系统相结合,实现EPON系统的无线接入服务.通过对这两种技术相结合的可行性的理论分析,对所提出系统的架构进行了描述,并通过系统测试验证了所提出系统的可行性和有效性.     

Rate adaptive speech coding for universal multimedia access

This article reviews state-of-the-art in transport adaptation techniques for mobile networks. It discusses the mechanisms for rate adaptation to combat quality degradations of speech caused by the radio links. It begins with a review of dynamic schemes for adaptation of speech encoders in cellular networks where we observe two distinct approaches to rate adaptation: network controlled and source controlled. The issues associated with adaptive voice over IP (VoIP) mechanisms are considered next. Here, the encoder detects some form of network congestion to judge how to behave itself for the good of the network. It is noted that this altruistic behavior will only benefit coordinated IP networks such as private intranets and its application to the public Internet is improbable.     

无线多媒体接入中的超宽带技术

简要介绍了超宽带(UWB)的概念及发展过程，通过与现有短距离无线接入技术的比较，表明它在无线多媒体接入系统中具有传输速率高、空间容量大等特点，分析了尚需解决的关键技术并展望了应用前景。     

Packet reservation multiple access for wireless multimedia communications

Packet reservation multiple access (PRMA) is portrayed as a multimedia packet multiplexer conveying speech, data and video signals, which ensures that the slot occupancy of conventional time division multiple access (TDMA) links is approximately doubled. In addition to 20 speech users the 20 slot 720 kbit/s scheme presented supported 20 data users and up to seven video users, while maintaining a slot occupancy in excess of 80%.<>     

支持多媒体业务的接入控制技术研究进展

如何保障不同类型的多媒体业务在通信过程中的通信服务质量(QoS),是目前接入控制技术中一项热点研究问题。通过对近十几年间相关文献的整理和分析,对支持多媒体业务的接入控制技术的研究进展进行综述,具体内容包括多媒体业务类型的设计、支持多媒体业务的接入控制协议、多信道分配策略等方面,并提出了支持多媒体业务的接入控制技术未来的研究方向。     

Provision of multimedia services: the key to deployment of accessnetwork architectures in developing countries

Access networks have always been a very significant part of public network operator investments and operating costs. They have not, however, been a very dynamic part of telecom networks, planned, as they were, for the long term and usually with limited technological innovation. This is changing, and access networks are increasingly coming into focus for technological innovation and as platforms for provisioning new advanced services in a competitive business environment. New fiber, radio, and copper-based technologies, in combination with flexible multiplexers and management tools, provide new possibilities for improved quality of services, cost reduction, and provisioning of new advanced services. In order to fully benefit from these possibilities, to extend and upgrade existing as well as build completely new access networks, a flexible service-independent access network architecture and access network system are required. In this article a target access network architecture is suggested as well as an implementation scenario for developing countries     

A direct signaling system for flexible access and deployment oftelecommunication services

In current telecommunication networks, the value-added services available to subscribers are almost exclusively offered by the carrier providing local telephony service. This results from two factors: the processing for services is either based in or triggered from software executing on the access telecommunication switches, and signaling links over which subscribers request services are terminated on these access switches. In a direct signaling system, the signaling link from a subscriber does not necessarily terminate on an access switch, but rather on an intelligent server we call a call server. The call server invokes service functions and coordinates their interactions. This direct signaling system may be overlaid on various types of access networks, including circuit-switched telephony, packet telephony, wireless local loop, cable, etc. We discuss the design, implementation, and performance of a direct signaling system, including procedures that provide varying amounts of integration with current telecommunication systems. Our results show that a direct signaling system using a low-delay direct signaling link and in which no changes are made to existing telecommunicatione switches incurs approximately 100 ms higher postdial delay than a standard ISDN system. A direct signaling system in which telecommunication switches provide open interfaces and coordinate processing with direct signaling servers incurs approximately 100 ms lower postdial delay than a standard ISDN system     

基于IMS技术的三网融合网络多媒体业务部署

提出了基于云计算架构的三网融合网络多媒体视频业务部署技术,解决了三网融合网络海量终端用户访问及多媒体业务及用户的管理等问题.给出了三网融合网络的多媒体视频业务管理模型,并且详细说明了多媒体视频应用服务器及客户端的功能模块,以实例方式说明了QoS策略决策过程.为三网融合网络多媒体业务部署提供了指导性的技术方案.     

Adaptive access points deployment for Indoor bluetooth positioning accuracy enhancement

The indoor positioning system based on fingerprint receives more and more attention due to its high positioning accuracy and time efficiency. In the existing positioning approaches, much consideration is given to the positioning accuracy improvement by using the angle of signal, but the optimization of access points (APs) deployment is ignored. In this circumstance, an adaptive APs deployment approach is proposed. First of all, the criterion of reference points (RPs) effective coverage is proposed, and the number of deployed APs in target environment is obtained by using the region partition algorithm and full coverage algorithm. Secondly, the wireless signal propagation model is established for target environment, and meanwhile based on the initial APs deployment, the simulation fingerprint database is constructed for the sake of establishing the discrimination function with respect to fingerprint database. Thirdly, the greedy algorithm is applied to optimize APs deployment. Finally, the extensive experiments show that the proposed approach is capable of achieving adaptive APs deployment as well as improving positioning accuracy.     

Medium access control protocols for multimedia traffic in wirelessnetworks

This article presents a survey on medium access control protocols for multimedia traffic in wireless networks. A basic overview of MAC protocol concepts is presented, and a framework is developed on which to base qualitative comparisons. The MAC protocols covered include third-generation TDMA and CDMA schemes intended for use in a single-hop wireless system. The operation of each protocol is explained, and its advantages and disadvantages ore presented. Finally, a qualitative comparative outline of the discussed protocols is provided, based on multimedia traffic requirements