A multicast mechanism for mobile multimedia messaging service

Based on the cell broadcast service architecture, this paper proposes an efficient multicast mechanism for the universal mobile telecommunications system to support multimedia messaging service (MMS). We define a new interface between the serving GPRS support node and the cell broadcast center to track the current locations of the multicast members. Then we describe the location tracking procedures (including attach, detach, and location update) of the multicast members and the multicast message delivery procedure. We use an analytic model to investigate the performance of our approach. This paper indicates that our MMS multicast mechanism outperforms the previous proposed approaches.     

MHEGAM-a multimedia messaging system

MHEGAM (MHEC-1 Advanced Mail) is a complete multimedia messaging system for the creation, exchange, and restitution of multimedia messages that express spatial and temporal synchronization among their components. MHEGAM can be based on the standard messaging systems X.420 or MIME. We present the multimedia extensions MHECAM-X.420 and MHEGAM-MIME and discuss the multimedia message format and architecture components for both systems     

移动智能网多媒体消息业务的体系结构及其协议

多媒体消息业务(MMS，multimedia messaging service)作为一种新的移动数据业务已经得到了大规模的应用，在移动智能网上也可以支持这种业务。ITU-T、ETSI对移动智能网支持MMS并无相应的规范，目前国内计划采用的是SCP(service control point)与MMSC(multimedia messaging service center)互联的解决方案。本文在对此方案做详细分析的同时，提出了基于CAMEL(customized application for mobile enhanced logic)的MMS体系结构，并对此进行了深入的探讨。在此基础上，分析计算了智能多媒体消息业务对SCP及信令链路造成的影响。     

视讯业务产业链分析

随着经济的发展，通信已成为人们不可缺少的交流手段，个人间、政府部门间、企业与其合作伙伴及客户间需要高效、可靠的交流工具。据统计，在人类的通信与交流当中，有效信息的50%～60%依赖于面对面的视觉效果。视讯会议以其方便、快捷、“面对面”交流的优点逐渐得到了人们的认可，可以预计，以视频会议为代表的多媒体通信将具有极为广阔的市场和应用前景。国内各大运营商也纷纷筹备和建设各自的视讯会议网。原中国电信进行了原有视讯会议网的升级和改造，中国铁通、中国联通都建设了大规模的视讯会议网，中国网通也正进行着前期的筹备工作…     

Implementation and performance evaluation for a ubiquitous and unified multimedia messaging platform

As networking technology advances, more advanced message services are provided. Users may have one or more different message accounts and devices. Before sending messages, the sender must make sure which message service the receipt currently uses. Any misjudgement may delay the time when the messages are received. To make users be able to receive messages anytime and anywhere with any kind of devices, we propose a Ubiquitous and Unified Multimedia Messaging (UMM) platform. The UMM platform integrates different message services and provides a more efficient way for message delivery. Our design does not modify the existing protocols of message services and need not involve the network operators. An analytical model is proposed to evaluate the performance of the implemented platform. Our study shows that with a large number of message services the user subscribes and long message processing time in the network, the delayed message probability can be limited within 1.5%. This performance is considered satisfactory. This paper is an extension of the work that has won the second place of the Mobile Hero contest sponsored by Industrial Development Bureau of Ministry of Economic Affairs, Taiwan, R.O.C., and was awarded USD 15,000. Phone Lin (M’02-SM’06) received his BSCSIE degree and Ph.D. degree from National Chiao Tung University, Taiwan, R.O.C. in 1996 and 2001, respectively. From August 2001 to July 2004, he was an Assistant Professor in Department of Computer Science and Information Engineering (CSIE), National Taiwan University, R.O.C. Since August 2004, he has been an Associate Professor in Department of CSIE and in Graduate Institute of Networking and Multimedia, National Taiwan University, R.O.C. His current research interests include personal communications services, wireless Internet, and performance modeling. Dr. Lin is an Associate Editor for IEEE Transactions on Vehicular Technology, a Guest Editor for IEEE Wireless Communications special issue on Mobility and Resource Management, and a Guest Editor for ACM/Springer MONET special issue on Wireless Broad Access. He is also an Associate Editorial Member for the WCMC Journal. Dr. Lin has received many research awards. He was a recipient of Research Award for Young Researchers from Pan Wen-Yuan Foundation in Taiwan in 2004, a recipient of K. T. Li Young Researcher Award honored by ACM Taipei Chapter in 2004, a recipient of Wu Ta You Memorial Award of National Science Council (NSC) in Taiwan in 2005, a recipient of Fu Suu-Nien Award of NTU in 2005 for his research achievements. Dr. Lin is listed in WHO’S WHO IN SCIENCE AND ENGINEERING(R) in 2006. Dr. Lin is a Senior Member, IEEE. P. Lin’s email and website addresses are plin@csie.ntu.edu.tw and respectively. Shan-Hung Wu received the B.S. degree from Department of Information Management, National Central University, Jhongli, Taiwan, and M.S. degree from Department of Computer Science and Information, National Taiwan University, Taipei, Taiwan. He is currently a Ph.D. candidate at Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan. His research interests include distributed data management, pervasive computing, wireless and sensor networks, and performance modeling. Chung-Min Chen is Director of Telcordia Applied Research Center in Taiwan. His research interests span across areas in distributed computing, data engineering, telecommunication and network management. He received a Ph.D. in Computer Science from the University of Maryland, College Park and a B.S. in Computer Science and Information Engineering from National Taiwan University. Ching-Feng Liang received M.S. degree in electronic engineering from National Taiwan University of Science & Technology (NTUST) in 1993 and joined the Information & Communication Laboratory (ICL) of Industrial Technology Research Institute (ITRI) as an engineer. Liang has led more than 10 projects of Taiwan Ministry of Economic Affairs (MoEA) to study and develop the technologies of mobile network and services including GPRS/3G core network, WLAN/Cellular interworking and number portability service. Liang received the ITRI Award in 2005 and the Outstanding Project Award of Taiwan MoEA in 2003. Liang is currently the manager of the Core Network Department of ICL/ITRI.     

Quality of service for multimedia CDMA

This article investigates the problem of call admission control in cellular networks using code-division multiple access, which is mainly viewed as an interference management problem. Our approach is to study the effects of various system parameters and user profile characteristics on the generation of multiple access interference (MAI). Different CAC schemes are presented, and different user and system characteristics that affect the CDMA system operation are listed. The focus of our work is on the emerging third-generation wireless systems and particularly on the Universal Mobile Telecommunications System. Analytical and simulation tools were constructed for quantifying these system characteristics. The results obtained by these two models show that the outage probability for a system is very sensitive to the user bit rate and quality of service requirements. The combination of different service types has a significant effect too; even a small number of high-bit-rate users can degrade the low-bit-rate users' performance and considerably increase their outage probability. The use of a CAC algorithm is expected to guarantee the service offered to accepted users     

宽带多媒体业务的业务量模型

针对三类基本的信源，数据，音频和视频，对现有宽带多媒体业务的业务量模型进行了探讨和分类，并总结了业务量模型的选择标准。最后，对这些模型给出了评价。     

A mobile spatial messaging service for a grassroots environmental network

Information and communication technology are potentially significant tools in strengthening local initiatives towards sustainability. The Science and Technology (S&T) Framework for Sustainable Development provides a context for such development. This article describes a study aimed at examining how the existing mobile technologies of standard messaging service and wireless application protocol can be used to support the activities of an environmental grassroots organisation–London 21 Sustainability Network (henceforth London 21). Following the S&T Framework, it is clear that to realise the potential of these technologies a new mobile service should be effectively embedded into the structure and activity of the network. Using a participatory research approach, an extensive user requirements study with 273 participants was carried out to ensure that the development of the mobile service for London 21 fulfils the purposes, goals and expectations of the organisation.

This article describes a Mobile Spatial Messaging Service, called EcoTEXT, which was developed and deployed for London 21. This service allows individuals to receive geographically targeted, action-orientated, time-relevant information via text messages on their mobile phones. The content of the service is information about upcoming local environmental events and activities, which match the interest of the user, when these events occur in close spatial proximity to where that user resides. This type of service represents a powerful new dimension for the provision of data-driven services in comparison to current text-based services. Location is giving the service additional meaning and value. The introduction of such a service into the organisation's communication toolkit offers the potential to create, supplement and strengthen social ties and interactions within the community.     

Security for multimedia adaptation: architectures and solutions

Multimedia content adaptation enables users with different access networks, client devices, and/or user profiles to access the same information source. However, content adaptation also introduces security implications. We conduct an in-depth investigation into the potential security issues involved and analyze general security architectures and requirements. In particular, we address the issue of where to place the security functions and how this affects functionality.     

多媒体消息服务

MMS是3GPP规范中定义的移动数据业务,它利用WAP协议作承　载,短消息作通知,用户可以像使用短消息一样收发更加个性化的多媒　体消息,如:文本、图形、图像、音频、视频、动画、音乐等信息内容。　 多媒体消息服务要求一个WAP/PUSH代理网关、适用于大量信息传　输的配置、一个数据传输网如电路交换网、GPRS或UMTS网络,和一个　短消息中心。MMS业务以WAP作承载,短消息作提示通知,纯属应用层　业务。多媒体信息中心（MMS-C）并不直连核心移动网络,而是通过HTTP PAP（PushAccessProtocol）连接WAP网关,SMPP连接SMS-C。 　 多媒体消息服务并不依赖于哪一代网络,它能够在第2代、第2.5代　及第3代无线网络中实施。无论CSD、HCSD,还是EDGE、GPRS、UMTS,　都可以支持MMS业务。鉴于网络带宽、传输速度和移动终端方面考虑,　MMS业务将在当前GPRS网络上起飞,在未来3G网络中走向成熟。 　当前MMS手机支持以下几种业务方式:手机端到端双向收发　MMS;手机到E-mail双向收发MMS;Web向手机下发MMS。     

Multimedia adaptation in end-user terminals

In the last few years, considerable research efforts have been spent on the concept of adaptation at various points in the digital information distribution chain, from content/service generation to end-user terminals. The purpose of these efforts is to realize the Universal Media Access (UMA) vision, which means access to content by any terminal and any network. The quality of the user experience then depends on the effectiveness of the multimedia customization process. Complementary to these efforts, this paper addresses the problem of adapting the playback of a multimedia application in multimedia end-user terminals by (1) showing its relationship with MPEG-21 concepts, (2) framing it in the context of terminal Quality of Service (QoS), (3) presenting a complete framework based on the MPEG-4 systems’ architecture and (4) finally presenting some results.     

Designing an on-demand multimedia service

A quantitative study of techniques for designing a high-performance multiuser multimedia on-demand information service is presented. The problem of maintaining continuity of playback of each media stream in the presence of multiple subscriber requests is formulated, and admission control algorithms that permit a multimedia server to satisfy the maximum number of subscribers simultaneously are presented. A feedback technique in which a multimedia service uses lightweight messages called feedback units that are transmitted back to it by subscribers' mediaphones to detect asynchrony among them and steer them back to synchrony thereafter is presented. The feedback technique guarantees synchronous playback of media streams transmitted by the multimedia server to subscribers over metropolitan-area networks     

Multimedia and multimedia communication: a tutorial

This paper presents, in a tutorial fashion, the important features of multimedia technology. The specific areas addressed are multimedia and compression standards, computer networks, multimedia transport, and some specific applications employed by industry to date. Multimedia and the effective and efficient communication of multimedia using compression and networks are fused together in this tutorial in an attempt to demonstrate the tight coupling which exists between these two interrelated technologies. First, the techniques and properties inherent in both multimedia and compression standards are presented. Then, the important characteristics of the major local and wide area networks are summarized. Next, the communication techniques for the transport of video and video conferencing are discussed. The new strategies employed to connect homes through cable TV and the telephone companies, as well as the new Ethernet technologies, are also described. Finally, some modern applications of multimedia communication derived from the automotive industry are used to describe the use of this technology in design, manufacturing, and sales     

QoS-aware adaptation for satellite multimedia broadcasting via hierarchical packet scheduling

With the unique broadcast nature and ubiquitous coverage of satellite networks, the synergy between satellite and terrestrial networks provides opportunities for delivering wideband services to a wide range of audiences over extensive geographical areas. This article concerns the optimization techniques pertinent to packet scheduling to facilitate multimedia content delivery over the satellite with a return channel via a terrestrial network. We propose a novel hierarchical packet scheduling scheme that allocates the resources at different parts of the network in response to network dynamics and link variations while under the system power/resource constraints. Simulations prove that the HPS scheme can effectively improve the end-to-end performance and resource utilization with desirable scalability and fairness features.     

Scheduling schemes for multimedia service in wireless OFDM systems

Scheduling schemes play a key role in the system performance of broadband wireless systems such as WLANs/WMANs. Maximal SNR and round robin are two conventional scheduling strategies that emphasize efficiency and fairness, respectively. The proportional fair scheme provides a trade-off between efficiency and fairness, and has been well studied in TDMA and CDMA systems. In this article we extended the PF scheduling scheme to OFDM-based BWSs (OPF). In addition, we propose three variations: adaptive OPF (AOPF), multimedia AOPF (MAOPF), and normalized MAOPF (NMAOPF) in order to meet the QoS requirements for multirate services in multimedia systems. The adaptive modulation and coding schemes in time varying and frequency selective fading are considered. The system performances of the algorithms are compared in terms of efficiency (throughput and mean packet delay) and fairness (user satisfaction rate and average user rate). Joint physical and media access control layer simulation results show that AOPF and MAOPF can improve throughput at the cost of fairness, and NMAOPF can provide the highest throughput without losing fairness.     

QoS and multipoint support for multimedia applications over the ATMABR service

Multimedia applications with stringent delay requirements are usually supported by the constant bit rate (CBR) or real-time variable bit rate (rt-VBR) service categories of ATM. This article shows that the available bit rate (ABR) service, which was originally designed for data, can also support multimedia applications under certain circumstances. Issues related to the design of proper ABR traffic management algorithms for such support are presented     

The multimedia broadcast/multicast service

This article provides an overview of the multimedia broadcast/multicast service (MBMS) for universal mobile telecommunications system (UMTS) networks. We first outline the features of UMTS networks as defined by the 3rd generation partnership project (3GPP) in order to provide a background for the discussion to follow. We then present the overall MBMS architecture, the services that it provides to the users and the differences between the broadcast and multicast options. The implementation details of MBMS are explained in terms of the modifications needed to the network, the new signaling procedures required and the impact of MBMS on the radio part of the network. We then describe how the security architecture of UMTS is used to support content protection and key distribution for MBMS groups. We evaluate the prospects of MBMS by comparing it first with IP multicast and then with DVB‐H, considered by many to be the closest competitor of MBMS. Finally, we conclude with a discussion of the technical and business challenges still faced by MBMS. Copyright © 2006 John Wiley & Sons, Ltd.