Supporting real-time IP multimedia services in UMTS

UMTS, the successor of GSM, is evolving toward a future wireless all-IP network. We explain how it will support real-time IP multimedia services, as these services are expected to drive the adoption of wireless all-IP networks. We not only focus on the centerpiece of IP multimedia support, the IP multimedia subsystem, but also include the GPRS transport capabilities and OSA middleware capabilities. This helps to explain how the IMS fits in with, and builds upon, other pieces of the UMTS network. We analyze the pros and cons of providing IP multimedia session control capabilities as opposed to just providing basic IP connectivity, and highlight selected features of the IMS design for discussion.     

Supporting mobile multimedia applications through adaptivemiddleware

The traditional approach to developing middleware platforms is to adopt a “black box” philosophy whereby the platform offers a fixed programming model to applications together with fixed per-platform implementations. In this paper, we describe research which is exploring an open approach to the implementation of middleware platforms. Our motivation is to accommodate the demanding requirements for quality-of-service (QoS) adaptation as imposed by mobile multimedia applications. We use an extended CORBA computational model featuring the concept of explicit open bindings. This provides an architectural framework for openness and QoS adaptation. The paper concludes by considering the more general application of an open systems philosophy; in particular, we introduce the concept of reflective middleware     

Supporting multimedia applications through network redesign

Recent evolutions in high‐performance computing and high speed broadband Internet access have paved a way to enterprise‐wide multimedia applications, which require stern QoS from the underlying networks. In this paper, we have explored threefold studies on existing enterprise network, whereby we proposed an analytical approach to evaluate the performance of the existing network; we have examined the feasibility of existing enterprise networks to accommodate voice over Internet protocol (VoIP) services with acceptable QoS, and we have redesigned the enterprise network to accommodate VoIP services to comply with the user defined QoS. The network performance is evaluated by number of VoIP calls sustained by the network, bandwidth utilization, loss rate and latency through Network Simulation (NS‐2) tool. We have derived a cost model to show the cost‐effectiveness of VoIP services over telephonic network. For a medium‐size enterprise network of 200 clients and 9 servers, our simulation results show that the redesign improves the network performance by increasing the number of VoIP calls by 57% and decreasing bandwidth utilization and packet loss rate by 20% and 7%, respectively. Moreover, the proposed network redesign demonstrates that the network can be scalable and it can handle up to 4% increased voice calls in the future maintaining QoS standards. Copyright © 2012 John Wiley & Sons, Ltd.     

Distributed multimedia applications on gigabit networks

MultiG, an open research program addressing issues that range from end-user requirements on distributed multimedia applications supporting collaborative work to medium-access protocols for multi-gigabit networks on optical fibers, is discussed. The projects in MultiG are described from the top down, beginning with computer-supported cooperative work. Distributed multimedia applications and application generators are then considered, followed by networking issues, including interprocess communication, transport services, network protocols, and high-speed protocol processing. Testbed activities and future plans are described     

网络化多媒体实时监控系统的应用研究

采用MPEG－1编码解码国际标准和TCP／IP网络协议,在网络环境下,实现视音频信息和控制数据的网上传输。介绍了网络化多媒体实时监控系统的的构成、工作原理和功能特点,并对视音频实时编码技术和网络编程技术进行了详细探讨。     

Supporting mobile multimedia in integrated services networks

Owing to widespread user mobility, limited radio resources, and changing network characteristics, supporting multimedia communications in a mobile internetworking environment is a challenging problem. In this paper, we present an adaptive reserved service framework for use in integrated services networks to support mobile connections carrying multimedia traffic. Integrated in the framework are an anticipatory handoff control mechanism which enables fast handoff, and an adaptive link partitioning scheme which enhances handoff success. Besides, bandwidth reservations in the wireline network are dynamically adjusted based on resource availability in the wireless networks. An accompanying reservation protocol not only facilitates distributed control of mobile connections but also provides network feedback to mobile hosts.An earlier version of this paper appeared in the First International Conference on Mobile Computing and Networking, 1995.     

Quality-of-service support for multimedia applications

A major project at Lancaster University is the development of network infrastructures capable of supporting the quality-of-service (QoS) requirements of a wide range of distributed multimedia applications. The project includes more than thirty researchers and covers not only the network support but also the enabling technologies. The authors believe that QoS development cannot be done in isolation from the applications to be supported, which must form an integral part of the project. They focus on three application areas: interactive teaching and learning, mobile systems, and virtual reality. They chose applications that stretch network support to its limit. To realize the full potential of these distributed multimedia applications, the underlying network must satisfy all these requirements concurrently. They give a brief overview of their activities to this end and discuss the need for QoS support     

面向多媒体应用的超高速USB

USB 3.0是什么?你能用它来干什么? USB 3.0推广小组成立于2007年英特尔信息技术峰会.6个成员公司(惠普、英特尔、微软、NEC、ST-NXP Wireless、德州仪器)起草了最初的规范,并与其他参与公司共同成立了由200名业内专家组成的组织,以确保在规范发布时能够获得广泛的支持.     

Developing distributed multimedia telecommunication applications

The emerging open services market transforms services into tradable goods. It involves users; customers; service, content, and middleware providers; and network operators. This market requires effective methods to: provide new services to meet niche market demands; support customized services; provide appropriate accounting and billing mechanisms; support personal and terminal mobility, and meet information interchange security requirements such as authorization, confidentiality, and integrity. Efficient processes will reduce investment risks and let us benefit from software and hardware product development advances. To meet these needs requires an appropriate infrastructure that supports the object oriented development of distributed multimedia telecommunication applications     

An architecture for real-time multimedia communication systems

A multimedia communication system includes both the communication protocols used to transport the real-time data and the distributed computing system (DCS) within which any applications using the protocols must execute. The architecture presented attempts to integrate these communications protocols with the DCS in a smooth fashion in order to ease the writing of multimedia applications. Two issues are identified as being essential to the success of this integration: the synchronization of related real-time data streams, and the management of heterogeneous multimedia hardware. The synchronization problem is tackled by defining explicit synchronization properties at the presentation level and by providing control and synchronization operations within the DCS which operate in terms of these properties. The heterogeneity problems are addressed by separating the data transport semantics (protocols themselves) from the control semantics (protocol interfaces)     

Supporting next-generation distributed applications

Even the current euphoria over the World Wide Web doesn't do full justice to the Internet's potential. With the manifold increase in CPU processing power and network bandwidth, it's inevitable that the Internet will support increasingly complex distributed applications. While information retrieval applications dominate the Internet today, the next-generation Internet will likely offer applications that can process massive amounts of data for visualization and support real-time interactivity. For instance, a digital library of satellite imagery might be processed for feature extraction or visualization. A virtual environment for training fire fighters might involve distributed simulations and real-time user interactivity. In 1994, the University of Texas at Austin opened the Distributed Multimedia Computing Laboratory (DMCL) to conduct the basic and experimental research necessary to address the problems of these emerging applications. The research work done at DMCL can be broadly classified into the following categories: resource management techniques that meet the performance requirements of applications (the Symphony, NetCop, and OSng projects); an information delivery architecture that meets the scalability requirements of applications (the Trellis project); a fault-tolerance framework for cooperative distributed applications (the Coyote project); an environment for creating and disseminating digital educational material over the Internet (the InfoWeave project). The article summarizes key research findings and ongoing projects at DMCL     

On the applications of multimedia processing to communications

The challenge of multimedia processing is to provide services that seamlessly integrate text, sound, image, and video information and to do it in a way that preserves the ease of use and interactivity of conventional plain old telephone service (POTS) telephony. To achieve this goal, there are a number of technological problems that must be considered, including: compression and coding of multimedia signals, including algorithmic issues, standards issues, and transmission issues; synthesis and recognition of multimedia signals, including speech, images, handwriting, and text; organization, storage, and retrieval of multimedia signals, including the appropriate method and speed of delivery, resolution, and quality of service; access methods to the multimedia signal, including spoken natural language interfaces, agent interfaces, and media conversion tools; searching by text, speech, and image queries; browsing by accessing the text, by voice, or by indexed images. In each of these areas, a great deal of progress has been made in the past few years, driven in part by the relentless growth in multimedia personal computers and in part by the promise of broad-band access from the home and from wireless connections. Standards have also played a key role in driving new multimedia services, both on the POTS network and on the Internet. It is the purpose of this paper to review the status of the technology in each of the areas listed above and to illustrate current capabilities by describing several multimedia applications that have been implemented at AT&T Labs over the past several years     

Transport layer for cooperative multimedia applications

This paper presents work carried out within the Cesame project for the design of a multimedia highspeed distributed transport provider. The term transport provider is used to target a reference framework but does not preclude any standardized reference model. It gives the objectives and relates the main contributions obtained during the first year of the project. The goal of this task is to monitor, select and design services, protocols and mechanisms for defining a transport provider to support distributed multimedia services. As far as architectural aspects are concerned, a refinement of reference models is mandatory, and work on this topic has already been started within several institutions. Moreover, it is worth to mention that the transport provider will have first to run on top ofAtm/Aal networks and is expected on top of other networks.     

High-speed memory architectures for multimedia applications

In order to meet the requirements for multimedia applications, several approaches to DRAM architecture have emerged. Instead of a single, common memory device, several advanced approaches, such as extended data out (EDO) DRAM, and synchronous DRAM (SDRAM) will each play a major role in the future memory market. Furthermore, advanced interface technologies, such as Rambus RAM (RDRAM), RamLink, and SyncLink are very promising for future-generation memory. Also, application-specific memory, such as cache DRAM (CDRAM), enhanced DRAM (EDRAM), and video DRAM (VRAM) offer unique characteristics to improve performance in particular applications. Since it is beneficial to understand which type of high-speed memory can improve the speed performance of a particular system most effectively, this article discusses the fundamental concepts of these recent high-speed performance memory architectures to aid in the selection of memories for multimedia applications     

Adaptive rate-controlled scheduling for multimedia applications

We present a framework for integrated scheduling of continuous media (CM) and other applications. The framework, called ARC scheduling, consists of a rate-controlled on-line CPU scheduler, an admission control interface, a monitoring module, and a rate adaptation interface. ARC scheduling allows threads to reserve CPU time for guaranteed progress. It provides firewall protection between threads such that the progress guarantee to a thread is independent of how other threads actually make scheduling requests. Rate adaptation allows a CM application to adapt its rate to changes in its execution environment. We have implemented the framework as an extension to Solaris 2.3. We present experimental results which show that ARC scheduling is highly effective for integrated scheduling of CM and other applications in a general purpose workstation environment. ARC scheduling is a key component of an end system architecture we have designed and implemented to support networking with quality of service guarantees. In particular, it enables protocol threads to make guaranteed progress     

微型硬盘激活中高端多媒体移动市场

在MP3播放机、多媒体播放器以及智能手机成为新的消费增长点时,适合便携设备的巨量存储手段成为制约手持设备发展的一个瓶颈.事实上,便携产品的设计者总是要在如何更高效地利用存储空间上费尽心思.在人们尝试着将视频内容放入便携设备时,巨量存储更是一个必要的配备.虽然闪存技术的价格/容量比逐年下降,但仍不如机械式硬盘技术的微型化来得更加快捷.     

Seamless SIP-based mobility for multimedia applications

Application-level protocol abstraction is required to support seamless mobility in next-generation heterogeneous wireless networks. Session initiation protocol (SIP) provides the required abstraction for mobility support for multimedia applications in such networks. However, the handoff procedure with SIP suffers from undesirable delay and hence packet loss in some cases, which is detrimental to applications like voice over IP (VoIP) or streaming video that demand stringent quality of service (QoS) requirements. In this article we present a SIP-based architecture that supports soft handoff for IP-centric wireless networks. Soft handoff ensures that there is no packet loss and that the end-to-end delay jitter is kept under control.     

Enabling multimedia applications for factory automation

Emerging multimedia communication and processing technologies enable many factory applications. However, these technologies are advancing at a prodigious pace. Therefore, designing, managing, and upgrading these networks within this fast-paced environment represents a formidable challenge. The various enabling technologies and the standards that control their use are the subject of this paper. Special emphasis is given to the use of these technologies to support developments on the factory floor. This strategy involves the use of video, audio, and data communications, as well as the inherent processing involved. The role that local area networks and the Internet play in the development of future factory applications is also discussed     

Satellite onboard processing for multimedia applications

For future multimedia applications, satellites might play an important role. For broadcast applications satellites are ideally suited to illuminate a large geographical area. However, multimedia applications are interactive, and are therefore a combination of a broadcast mission and a multipoint-to-point mission. The natural question is, can a satellite system compete with the capacity provided by terrestrial cable networks? If the answer is positive, and it shown in this article that it is, a second question arises: what new developments are required to migrate from the state-of-the art satellite technology to such advanced concepts? Taking the example of the European Space Agency's activities in this field, an overview of the required building blocks which make up a complete multimedia communication satellite system are described. Based on this technological overview a discussion of the systems developed by European space industries with support from the European Space Agency is given