Showing papers on "IP Multimedia Subsystem published in 1998"

Real-time voice over packet-switched networks

Abstract: We discuss the architecture and technical viability of transporting real-time voice over packet-switched networks such as the Internet. The value of integrating voice and data networks onto a common platform is well known. The telephony industry has proposed the ATM standard as a means of upgrading the Internet to provide both real-time and data services. In contrast, voice services may be added to traditional IP networks that were originally designed for data transmission alone. We consider the feasibility and expected quality of service of audio applications over IP networks such as the Internet. In particular, we examine possible architectures for voice over IP and discuss measured Internet delay and loss characteristics.

IP switching—ATM under IP

Abstract: Internet protocol (IP) traffic on the Internet and private enterprise networks has been growing exponentially for some time. This growth is beginning to stress the traditional processor-based design of current-day routers. Switching technology offers much higher aggregate bandwidth, but presently only offers a layer-2 bridging solution. Various proposals are under way to support IP routing over an asynchronous transfer mode (ATM) network. However, these proposals hide the real network topology from the IP layer by treating the data-link layer as a large opaque network cloud. We argue that this leads to complexity, inefficiency, and duplication of functionality in the resulting network. We propose an alternative in which we discard the end-to-end ATM connection and integrate fast ATM hardware directly with IP, preserving the connectionless nature of IP. We use the soft-state in the ATM hardware to cache the IP forwarding decision. This enables further traffic on the same IP flow to be switched by the ATM hardware rather than forwarded by IP software. We claim that this approach combines the simplicity, scalability, and robustness of IP, with the speed, capacity, and multiservice traffic capabilities of ATM.

Delivering Voice over IP Networks

Abstract: From the Publisher: An increasing number of companies are taking advantage of Voice over IP (VoIP) technology. Before implementing VoIP, companies must decide if the packetized voice should be delivered over Layer 2 networks such as ATM or Frame Relay, or over Layer 3 IP networks. This comprehensive book presents the latest standards and practices so you can determine which approach is best for your company. Drawing upon years of practical experience, the authors explore the unique engineering problems posed by running voice over a connectionless network. They clearly explain the advantages and disadvantages of IP versus traditional packet networks. This book is a significant expansion of the authors' first edition, which published in 1998 and had the distinction of being the first book in the industry dedicated to this important topic of key interest to enterprise customers.

On the applications of multimedia processing to communications

Abstract: 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.

Networked Multimedia Systems: Concepts, Architecture, and Design

Abstract: 1. Multimedia Systems Primer. 2. Multimedia Systems Requirements. 3. Multimedia Systems Technology: Coding and Compression. 4. Multimedia Systems Technology: I/O and Devices. 5. Multimedia Systems Technology: Networking. 6. Multimedia Systems Architecture. 7. Multimedia Systems Design: Traffic Analysis. 8. Multimedia Systems Design: Buffer Design. 9. Multimedia Systems Design: Traffic Shaping. 10. Multimedia Systems Design: Scheduling. 11. Multimedia Systems Design: Congestion Control. 12. Multimedia: System Design: System Software Trends. Appendix A. Multimedia Systems Technology: Standards. Acronyms. Glossary. Index.

Insights into mobile multimedia communications

Abstract: Preface Part 1. Research Trends and Technical Developments Part 2. Multimedia Services on Digital Cellular Networks Part 3. Third Generation Mobile Multimedia Systems Part 4. Source Coding: Speech and Audio Part 5. Source Coding: Video and Multimedia Part 6. Error Resilient Coding for Multimedia Applications Part 7. Advanced Radio Techniques Part 8. Wireless LAN Technology for Future Multimedia Services Index

Determining bearer services in a radio access network

Abstract: The invention relates to a method and an arrangement for supporting TCP/IP services in a cellular radio access network connected to a telecommunications network offering TCP/IP services. In accordance with the invention, the bearer service parameters required by different TCP/IP services are predetermined in the radio access network, the correct parameters for a given connection being selected by identifying the TCP/IP service on the basis of the content of the first IP packet (40) received (41-49). Thus, different TCP/IP services can be handled in different ways in the radio access network and a bearer service (50) that best corresponds to the actual needs can be established through the radio access network. In this way, good service quality to the user is ensured and, furthermore, optimization of the capacity of the radio access network is made possible when only correct-type capacity is reserved for each connection.

Communication and Computing for Distributed Multimedia Systems

Abstract: i»?i»?Guojun Lu Artech House, Cambridge, MA, 1996, 416 pp. ISBN 0-89006-884-4, $69.00 The telecommunications and computer industries are experiencing explosive growth. The most important trend is the convergence of the two in pursuing the promise of the information superhighway, a high-speed, ubiquitous, and seamless integrated services information infrastructure. The book Communication and Computing for Distributed Multimedia Systems by Lu focuses on a converged approach to development of distributed multimedia systems to meet the stringent requirements of multimedia computing and communications applications. It provides the first systematic discussion of issues and technology in developing networked multimedia systems. Each chapter covers issues related to an aspect of distributed multimedia systems and concludes with a summary, problems, and references. These help the readers better understand the text and provide insightful research directions for further investigations. The new concepts in each chapter are clearly defined, which clarifies the confusion caused by different new terms recently used in the literature. Chapter 1 introduces the fundamental concepts of multimedia computing and communications with sample applications. It also describes the different types of multimedia systems and the challenges of developing distributed multimedia systems. Chapter 2 presents the characteristics of multimedia data including digital audio, image, and video data. It then discusses the system requirements of processing multimedia data. It also includes a unique explanation of color specification and its role in achieving high picture quality, high compression ratio, and high information retrieval performance critical for future multimedia systems. Chapter 3 is devoted to the discussion of the principles and current techniques and standards for digital audio, image, and video compression which are very important, since multimedia data require a large storage to store and a large bandwidth to transmit. The challenge in developing distributed multimedia systems is to provide performance guarantees while using the network resources efficiently. Chapter 4 presents the end-to-end quality-of-service (QoS) framework for continuous media communication. In the next four chapters, the book discusses the support of QoS guarantee required at different layers of the communications network. Chapter 5 examines the characteristics of networks suitable for multimedia communication and discusses technical issues of QoS guarantees at the network layer. Chapter 6 covers the design issues of multimedia transport protocols and reviews a number of proposed multimedia transport protocols for the transport layer. Chapter 7 discusses the end-system support, including the support of hardware and operating systems, which is as important as network and transport support for multimedia communication. Chapter 8 is devoted to the discussion of a special type of end systems, multimedia servers. The book also covers techniques for networked multimedia synchronization and multimedia information indexing and retrieval. Chapter 9 discusses the requirements and mechanisms for intramedia and intermedia synchronization of multimedia data streams in distributed multimedia systems. Chapter 10 addresses how to organize multimedia information so that relevant information can be retrieved quickly from multimedia servers and techniques for indexing and retrieving multimedia information in distributed multimedia systems. The last chapter, Chapter 11, describes four current distributed multimedia systems: the World Wide Web (WWW), the Multicast Backbone (MBone), Video-on-Demand (VoD), and videoconferencing. The four systems can be considered as the primitive parts of the information superhighway. It concludes with a discussion of the general requirements and components of the information superhighway. From this book, the readers can learn about the special demands multimedia systems place on the computer architecture, storage, file system, operating system, and communications systems, and better understand the complex design challenges these components present. In addition, the readers can gain insight into current techniques and research efforts aimed at developing new computer architecture, operating systems, and communications systems to support multimedia. Looking ahead, the readers can catch a futuristic glimpse at the common networking paradigm evolved from the current telecommunications and computer networking models. Although the book has a relatively complete and balanced coverage of technical issues of distributed multimedia systems with QoS guarantees, it does not discuss two important issues that must be considered in development of distributed multimedia systems, security and user-friendly access. Hongchi Shi, University of Missouri-Columbia

Performance analysis of cellular mobile communication networks supporting multimedia services

Abstract: This paper illustrates the development of an approximate analytical model for a communication network providing integrated services to a population of mobile users, and presents performance results to both validate the analytical approach, and assess the quality of the services offered to the end users. The analytical model is based on continuous-time multidimensional birth-death processes, and it is focused on just one of the cells in the network. The cellular system is assumed to provide three classes of service: the basic voice service, a data service with bit rate higher than the voice service and a multimedia service with one voice and one data component. In order to improve the overall network performance, some channels can be reserved to handovers, and multimedia calls that cannot complete a handover are decoupled, by transferring to the target cell only the voice component and suspending the data connection until a sufficient number of channels becomes free. Numerical results demonstrate the accuracy of the approximate model, as well as the effectiveness of the newly proposed multimedia call decoupling approach.

Protocols for real-time multimedia data transmission over the Internet

Abstract: The explosive growth of the Internet and the intranets have attracted a great deal of attention to the implementation and performance of networked multimedia services, which involve the transport of real-time multimedia data streams over non-guaranteed quality of service (QoS) networks based on the Internet Protocol (IP). In this paper, the author presents an overview of the existing architectural elements supporting real-time data transmission over the Internet. Effective implementations of such systems require a thorough understanding of both the network protocols and the coding systems used for compressing the signals to be transmitted in real-time. The paper includes a section discussing the issues to be considered in designing signal compression applications suitable for network use.

Method and apparatus for integrated multimedia call control

Abstract: Method and apparatus for integrated multimedia call control. A unified way to manage incoming calls is provided for users who have both a public switched telephone network (PSTN) telephone and a computer workstation with a multimedia data communications client such as a client specified in International Telecommunication Union (ITU) Standard H.323. Calls from a PSTN phone in the network can be routed either to the user's PSTN telephone or the audio handling portion of the user's multimedia data communications client software. The audio portion of calls from a multimedia data communication client in the network can be routed either to the user's PSTN telephone or to the audio portion of the user's multimedia data communication client. Users can thus control PSTN and multimedia internet telephony calls in a consistent manner.

Bridging the gap to IP telephony

Abstract: Application of the Internet protocol (IP) as a network technology for telephony has the power to revolutionize the telecommunications industry. The bandwidth is flexible and almost free, and new services can easily be introduced. This abundance of services and bandwidth is the promise of IP telephony. Before this promise can be fulfilled, however, IP telephony needs to mature and bridge the gap to current telephone systems: the public switched telephone network (PSTN), the integrated services digital network (ISDN), and the wireless systems. Transferring telephone service to the IP domain is not a simple task. Solutions used in switched telephone networks may not be appropriate for the data world. On the other hand, the data world creates its own problems - addressing, reliability, and security are some examples. Initially, these problems may seem best solved by reusing protocols and ideas from the switched telephone world and adapting them to IP. However, tomorrow's problems may be created by such solutions. For example, should an IP telephony service be encumbered with legacy issues such as in-band tone signaling? In this paper, we give an overview of interesting issues in this area and provide a framework in which solutions to small problems can contribute to reaching the final goal of an IP-based telephony service.

Enhancing Wireless Internet Links for Multimedia Services

Abstract: | We describe a novel link layer protocol architecture that aims to enhance the performance of Internet protocols over wireless links, in particular in order to effectively support interactive multimedia applications with varying Quality-of-Service requirements. The degraded performance of these links on the Internet and the inadequacy of existing approaches in overcoming these problems in a protocol independent manner motivate our solution. Our design provides multiple services and performance feedback to higher layers, thus supporting adaptive protocols and applications. In addition, it serves as the basis for Internet evolution towards Quality-of-Service provision, since it can be used to support relevant mechanisms at higher layers, regardless of the underlying hardware.

Multimedia Communications Networks Technologies and Services

Abstract: Introduction. Multimedia Support in Shared Media Local and Metropolitan Area Networks. QoS Architectures. Traffic Management and Control. ATM Switching Systems for Multimedia Services. Transport Network Architectures and Technologies for Multimedia Services. Multimedia OA&M and OA&M Services. Wireless and Mobile Multimedia Networks. Multimedia Communications Services and Security Issues. Software Architecture for Multimedia Communication and Management. Standards for Multimedia.

Intelligent control of mobile multimedia systems

Abstract: The development of 3rd generation mobile systems such as UMTS and IMT-2000 should be enable the support a wide range of mobile multimedia services for users whilst on the move. To achieve this objective it is necessary to provide a set of flexible transport and control capabilities which service providers can use and adapt to support a wide range of mobile multimedia applications. The target is to extend the flexible capabilities of ATM and IP networks and services to mobile users. Control requirements of future mobile systems are considered for the support of mobile multimedia services.

A Platform for the Implementation of the Services of an Educational Network.

Abstract: Multimedia and hypermedia had and still have a tremendous impact on the evolution of educational software. In this paper we propose a platform for the implementation of the services of an educational network over TCP/IP networks such as the Internet. Our proposal aims at providing an integrated communicational environment which supplies the communicative needs of one educational community, using the latest telecommunication and multimedia information processing technology. We propose various kinds of communication forms for the interaction between the participants.

A tool for programmable access to organized multimedia data-Enhanced Multimedia Recorder (EMMR)

Abstract: The paper describes the "Enhanced Multimedia Recorder" (EMMR), which provides a programmable access method for multimedia data. The EMMR records heterogeneous multimedia data and then organizes them into meaningful units by dividing the recorded data using heuristic rules. The structured data representation within the EMMR framework can enable application programmers to access data segments organized from multimedia data.

Charging of Multimedia Flows in an Integrated Services Network

Abstract: Admission to communication services for multimedia applications does not imply purely technical control, it has to integrate economic admission policies as well. This is mainly due to the fact that multimedia communication services within the Internet cannot be assigned in a cooperative fashion as they represent bandwidth-hungry applications. Internet economics make various assumptions on pricing policies and services, encompassing features of the economic model, the pricing mechanism, the network model, and their practicability in the Internet today. Based on general architectural aspects for integrating and supporting charging and accounting properties of integrated services networks, the implementation of a flow-based approach to charge multimedia data in the Internet is presented. Ongoing work in the design, implementation, and evaluation of a control protocol for charging and accounting resource reservations in the integrated services Internet applies usage-based pricing models employing an auction-based pricing model (delta auction) and an adaptive, load-sensitive, volume pricing model. In contrast to packet-based charging schemes, the developed approach of flow-based charging features low processing overhead and low bandwidth requirements of less than 1% for finegrained and frequent reservation setups are achieved.

Design and implementation of Network CryptoGate-IP-layer security and mobility support

Abstract: As the commercial use of the Internet becomes common and the demand for mobile computing through the Internet is emerging, it is necessary to construct a secure mobile environment. The paper presents an implementation example of such a system: "Network CryptoGate (NGG)", which employs the IETF/Mobile IP and the IETF/IP security on stationary security gateways (NCG servers) and mobile hosts (NCG clients). Using IP security primitives, both packets going into a corporate network and packets going out of the visiting network are securely guarded. This IP security based packet control allows transparent mobile access from anywhere on an IP network with sufficient security support by encrypting and authenticating IP packets. Currently the NCG system is implemented on BSD/OS, Solaris and Windows NT/95. Preliminary performance measurements show that the proposed NCGs IPsec and Mobile IP processings are sufficient in the current Internet environment.

Network netplay: virtual groups on the internet [Book Reviews]

Abstract: This book introduces the TCPIIP-savvy reader to the design and implementation of Internet protocols useful for maintaining network connections while moving from place to place. It describes the technology that makes mobile networking possible; in particular , it focuses on Mobile IP, the Internet Engineering Task Force (IETF) standard for mobile networking. The book discusses mobile IP, route optimization, IPv6, use of Dynamic Host Configuration Protocol (DHCP), and encapsula-tion. After reading Mobile IP, a network engineer will be able to produce implementations of Mobile I P for mobile nodes, foreign agents, and home agents. Mobile IP requires precise handling of packetized control data; all the needed steps for handling that data are detailed. The necessary control mechanisms for handling advertisements are given first, followed by the main part of the IP protocol. In addition to the base protocol, the book also presents newly specified enhancements to Mobile IP, and details the protocol support needed for enabling mobile networks using IPv6. Interactions between Mobile IP and other protocols (e.g., DHCP) are described. Additional material includes ways to reduce registration traffic with the home network and first steps toward integrating mobile with enterprise security installations such as firewalls and border routers. Signal processing algorithms and architectures play an increasingly important role in meeting the central challenges faced in the design of advanced wireless communication systems. In Wireless Communications: Signal Processing Perspectives, leaders in the field describe state-of-the-art research in applying signal processing methodologies in the context of tomor-row's most important wireless applications , ranging from next-generation cellular telephony and personal communications services to nomadic computing and wireless multimedia. Wireless Communications: Signal Processing Perspectives is a reference for both signal processing specialists seeking to apply their expertise in the rapidly growing wireless communications field and communications specialists eager to exploit signal processing techniques and implementations to develop efficient wireless systems of the future. The book includes both physical-and network-layer topics: diversity strategies , interference suppression algorithms , equalization structures, array processing techniques, capacity measures and power control, network archi-tectures, data compression and coding, and underwater acoustic systems. The book also contains a thought-provoking essay on the laws of nature and society that ultimately govern wireless networks. Web Site Engineering systematically addresses the management, technical, and operational issues that arise when Web sites become sophisticated application deployment platforms. It builds on hard-won software engineering principles , defining a new model for Web site development …

Test results of the commercial internet multimedia trials

Abstract: This paper reports the test results of applications and services from the Commercial Internet Multimedia Trials. The Trials were a twelve-month effort by three companies to evaluate the product readiness of multimedia applications and services in business environments by supporting multimedia services on production IP networks. The test beds were enabled for IP multicast routing; one of the test beds was enabled for RSVP. The results of our RSVP tests and user surveys are reported, and some of issues related to the deployment of multimedia services and applications on corporate IP networks are considered.

Introduction strategy of photonic network technologies to create bandwidth-abundant multimedia networks

Abstract: Summary form only given. The recent explosion in Internet traffic implies the dawn of the multimedia age. Not only has the traffic volume of data communication increased, but also requirements for new service attributes are becoming more tangible. One important attribute that any future broadband multimedia network must possess is flexibility. It can be realized by the logical realization of transport functions. The key technology to enable this has been developed-ATM.

Management of Multimedia Networks and Services

Abstract: This paper proposes a generic component model which is a common software architecture applicable to the design of every component of a distributed telecommunications service. The concepts, principles and rules behind this model are introduced, and its architecture is detailed. It is then applied to the design of a broadband virtual private network service.

Modelling the delivery of multimedia services over Hiperlan

Abstract: Results from a detailed model of multimedia service delivery using the Hiperlan wireless LAN standard are reported. Hiperlan is shown to provide reasonable quality of service support for real-time services in several likely scenarios. However, the channel access prioritisation mechanism is shown to reduce to effectively two levels under conditions of network overload.

Making peace with your multimedia

Abstract: As multimedia applications grow in feasibility and popularity, multimedia information management becomes an increasingly critical task. Many data-representation and processing models for multimedia have been proposed and implemented, and as these options diversify, communication between them become harder.

Multimedia subscriber network

Abstract: Multimedia system, comprising a public IP-based multimedia network (1) and an access network for connecting local subscriber's premises (8). The access network is an IP-based local access network (2), being connected to one or more IP network nodes (6) and to local IP nodes (3) in the direct neighbourhood of the subscribers' premises (8). Said nodes may be IP routers. One local IP node (3) may serve one or more local subscriber's premises. The local subscriber's premises comprise at least one IP connection terminal (4a/4b), connected to said local IP node (3), to which IP connection terminal subscriber apparatuses (5) can be connected. The connection terminal may consist in a connection socket and a connection plug. An IP home network (9), to which various subscriber apparatuses are connectable, may be connected to said local node (3). The IP home network (9) may comprise one or more nodes (10).

Application of INAP to AIN Intelligent Peripheral

Abstract: As the infrastructure of the advanced intelligent network (AIN) has evolved, the intelligent peripheral (IP) has emerged as a major node for adding value to telephony services. It provides user friendly interfaces for customizing a service with various resources such as DTMF digit collection, voice announcement, voice recognition, video payload, and audio conference bridge, etc. We are developing a kind of networked IP which supports ISDN user part (ISUP) and intelligent network application protocol (INAP) for the communication with the service switching point (SSP) and the service control point (SCP) respectively. This paper describes the AIN IP architecture, telecommunication interface subsystem which is one of the four subsystems of IP, and functional blocks of INAP. The IP INAP provides application services by collating with the SCP, processed messages, and operations carried out at the IP, to provide specialized resource services with 3 ASEs which provides 7 operations. We applied this system to interface scenarios between the IP and other network elements and user interaction procedures.