Cost analysis and efficient radio bearer selection for multicasting over UMTS

Along with the widespread deployment of the Third Generation (3G) cellular networks, the fast‐improving capabilities of the mobile devices, content, and service providers are increasingly interested in supporting multicast communications over wireless networks and in particular over Universal Mobile Telecommunications System (UMTS). To this direction, the Third Generation Partnership Project (3GPP) is currently standardizing the Multimedia Broadcast/Multicast Service (MBMS) framework of UMTS. In this paper, we present an overview of the MBMS multicast mode of UMTS. We analytically present the multicast mode of the MBMS and analyze its performance in terms of packet delivery cost under various network topologies, cell types, and multicast users' distributions. Furthermore, for the evaluation of the scheme, we consider different transport channels for the transmission of the multicast data over the UMTS Terrestrial Radio‐Access Network (UTRAN) interfaces. Finally, we propose a scheme for the efficient radio bearer selection that minimizes total packet delivery cost. Copyright © 2008 John Wiley & Sons, Ltd.     

Location-Based Services — An Overview of the Standards

This paper traces the history of location-based service (LBS) standards that arose from North American requirements in the work on GSM standards in the late 1990s. It also describes how interest in GSM/UMTS outside Europe led to the creation of the Third Generation Partnership Project (3GPP) for developing UMTS standards (which include standards for the 3G mobile Internet). In addition, the paper covers the role of other standards bodies and interest groups involved in the creation of LBS standards such as the new Open Mobile Alliance.Different location methods for detecting the position of mobiles are described and a summary of the current work in 3GPP on LBS-based services and architecture for UMTS is given. The paper also covers work on wireless access protocols in the old WAP Forum     

The effect of platform instability on the system level performance of HAPS UMTS

High Altitude Platform Stations (HAPS) are a new, promising means of providing Third Generation (3G) mobile services. One of the potential problems of the system is the platform positional instability due to stratospheric winds. In this letter, we present a study of the effect of positional instability on the system level performance of a Universal Mobile Telecommunications System (UMTS) served by HAPS. A platform instability model obtained through measurements of stratospheric winds gives input into a UMTS system level dynamic simulator and the effect of instability on the system capacity and call blocking probability is examined. Finally, it is shown that the positional instability can be counterbalanced by a simple propulsion mechanism, thus reducing the performance degradation.     

TK‐AKA: using temporary key on Authentication and Key Agreement protocol on UMTS

Mobile communication is definitely one of the major high‐technology applications that offer present‐day people a modern life of appropriate convenience. In recent years, the third‐generation cell phone system has approached maturity. The Universal Mobile Telecommunication System (UMTS) is currently the most widely used system around the world. The Third Generation Partnership Project is equipped with the Authentication and Key Agreement (AKA) protocol to maintain secrecy and security both during the authentication process and during the telecommunication session through UMTS. However, Hung and Li have pointed out that the UMTS‐AKA protocol has three problems, involving bandwidth consumption, space overhead and synchronization of the sequence number, which are yet to be resolved. In addition, they have proposed an extension of the UMTS‐AKA protocol, named the X‐AKA protocol, to overcome these obstacles. Nevertheless, the X‐AKA protocol too appears to have problems of its own. In this article, the weaknesses of X‐AKA are enumerated. In addition, a more practical AKA protocol for UMTS is presented. The new protocol, based on the same framework as its predecessor, proves to be more efficient and practical, satisfying the requirements of modern living. Copyright © 2008 John Wiley & Sons, Ltd.     

An Efficient Mechanism for UMTS Multicast Routing

In this paper, we present a novel scheme for the multicast transmission of data over Universal Mobile Telecommunications System (UMTS) networks. Apart from the normal multicast transmission over UMTS, we consider the handling of exceptional cases caused by user mobility scenarios. The proposed scheme is in accordance with the current specifications of the Multimedia Multicast/Broadcast Service (MBMS) defined by the 3rd Generation Partnership Project (3GPP) and introduces minor modifications in the UMTS architecture and the mobility management mechanisms. The proposed scheme is implemented as an ns-2 network simulator module. The performance of the proposed scheme is validated and analyzed through ns-2 simulation experiments. This new module can be employed to investigate various aspects of UMTS multicast. Furthermore, in order to further highlight the contribution of our mechanism, we have implemented two multicast congestion control mechanisms for UMTS and we have measured their performance for MBMS transmissions.     

Effective Radio Resource Management for MBMS in UMTS Networks

Broadcast and multicast offer a significant improvement of spectrum utilization, and becomes particularly important where information channels are shared among several users. Mobile cellular environments are expected to evolve with the technological approaches necessary to facilitate the deployment of multimedia services, such as streaming, file download and carousel services. The perspective that video streaming in wireless networks services is an attractive service to end-users has spurred the research in this area. To provide for a video delivery platform in UMTS, the Third Generation Partnership Project (3GPP) addressed this problem with the introduction of the Multimedia Broadcast and Multicast Services (MBMS) in 3GPP Release 6. In this document we analyse several effective radio resource management techniques to provide MBMS, namely, use of non-uniform QAM constellations, multi-code and macro-diversity to guarantee the optimal distribution of QoS depending on the location of mobiles.     

A novel location management scheme for cellular overlay networks

In Beyond Third Generation (B3G) wireless communications, multiple overlays of wireless access networks may cooperate to allow a user access to novel services, the future demands of which will significantly increase the load on location management systems within the networks. In this paper, we introduce the reader to our novel proposals for providing efficient Mobile Terminal (MT) Location Discovery and Paging across an inter-worked network consisting a Digital Video Broadcast (DVB) network and Universal Mobile Telecommunication System (UMTS) network. We further present numerical and simulation analyzes of our scheme. The numerical and simulation results allow broadcast and cellular network operators to configure their inter-worked system to reduce location management and paging costs whilst controlling average latency. Our results demonstrate that our UMTS LA plus DVB paging schemes offer promise for efficient MT discovery in an inter-network environment that includes uni-directional broadcast network such as DVB; under realistic scenarios we achieve a minimum 4 times reduction in paging cost across the inter-network compared with independent paging systems. Furthermore, we briefly introduce further aspects of research that must be addressed in order to fully evaluate our proposals.     

Modeling frame synchronization for UMTS high-speed downlink packet access

Third Generation Partnership Project (3GPP) specification TR 25.950 proposed high-speed downlink packet access for the Universal Mobile Telecommunication System (UMTS). In this mechanism, an active set of cells is defined for every user equipment (UE) communication session. The cell with the best wireless link quality (called the serving cell) in the active set is selected for communication with the UE. When the wireless link quality of the old serving cell degrades below some threshold, a new serving cell in the active set is selected to continue the communication session. Our previous work proposed a high-speed downlink packet access (HSDPA) overflow control scheme with four frame synchronization algorithms to switch the serving cell, and formally proved the correctness of the scheme. We propose an analytic model to investigate the performance of these frame synchronization algorithms, and show how the user movement patterns affect the control message delivery costs of these algorithms.     

Analysis of end-to-end QoS for networked virtual reality services in UMTS

Virtual reality services may be considered a good representative of advanced services in the new-generation network. The focus of this article is to address quality of service support for VR services in the context of the UMTS QoS framework specified by the 3G standardization forum, the Third Generation Partnership Project. We propose a classification of VR services based on delivery requirements (real-time or non-real-time) and degree of interactivity that maps to existing UMTS QoS classes and service attributes. The mapping is based on matching VR service requirements to performance parameters and target values defined for UMTS applications. Test cases involving heterogeneous VR applications are defined, using as a reference a general model for VR service design and delivery. Measurements of network parameters serve to determine the end-to-end QoS requirements of the considered applications, which are in turn mapped to proposed VR service classes.     

An improved mechanism for multiple MBMS sessions assignment in B3G cellular networks

In Universal Mobile Telecommunication System (UMTS), the downlink capacity is limited by the base station transmission power. Therefore, power control plays an important role to minimize the transmitted power shared among unicast and multicast users within a cell. In Multimedia Broadcast/Multicast Service (MBMS), power control targets to the efficient utilization of radio and network resources. However, the expected high demand for such services stresses the need for an efficient scheme, capable of dynamically allocating radio resources to parallel MBMS sessions. This paper proposes a power control mechanism for efficient MBMS session assignment in next generation UMTS networks. The mechanism shares efficiently the available power resources of UMTS base stations to MBMS sessions running in the network. Furthermore, the mechanism is evaluated through several realistic scenarios and the results indicate the ability of the mechanism to utilize efficiently the radio resources and to ensure the service continuity when parallel MBMS services run in the network. Our approach is compared with current 3rd Generation Partnership Project (3GPP) approaches, such as these presented in TS 25.346 and in TR 25.922, in order to highlight the enhancements that it provides.     

第三代移动通信系统的未来--世界移动通信专家William.C.Y.Lee博士在北航报告摘录

１９９９年元月７日,移动通信领域的权威人士、美国ＡｉｒＴｏｕｃｈ通信公司副总裁兼首席科学家ＷｉｌｉａｍＣＹＬｅｅ（中文姓名：李建业）博士,应北京航空航天大学电子工程系的邀请,在北航逸夫科技馆做了题为“第三代移动通信系统的未来”的专题报告。Ｍｒ?..     

Mobile next-generation networks

Mobile next-generation networks (NGNs) are a necessary element in reaching the goal of truly ubiquitous computing. The Universal Mobile Telecommunication System, the third-generation mobile service concept, is a technology step to mobile NGNs. We can view NGNs as a merger of the Internet and intranets with mobile networks and with media and broadcast technologies. The Universal Mobile Telecommunication System (UMTS) is-from a radio perspective-a third-generation cellular technology, which is defined by the International Telecommunication Union (ITU) in its IMT-2000 framework (2001). From a conceptual point of view, it represents a technology step to mobile NGNs' facilitating ubiquitous computing. Researchers conceived UMTS to combine Internet protocol (IP) and mobile technologies to offer personal communication and personalized content everywhere. Its goal is to apply Internet protocols for mobile services control and end-to-end applications. By analyzing the trends of key technologies, we can see how they drive the evolution of the Internet and mobile communications toward mobile NGNs. In this article, I describe the IP-based approach of UMTS for the provision of mobile multimedia services. The integration of WLAN into the UMTS architecture could indicate that the field is moving toward separating mobile and fixed Internet.     

Exploiting MIMO Technology for Optimal MBMS Power Allocation

In mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance. To this end, Multimedia Broadcast/Multicast Service (MBMS)—that was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS)—is envisaged to play an instrumental role in the proliferation of mobile market. The reason behind the design of MBMS was the need to provide multiple users with the same data at the same time in 3GPP (3rd Generation Partnership Project) cellular networks. Still, MBMS performance is limited by the base stations’ transmission power. As an aftermath, efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This paper proposes a novel mechanism for efficient radio bearer selection during MBMS transmissions. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Furthermore, the mechanism exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas and manages to efficiently deliver multiple MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with the radio bearer selection mechanisms proposed by 3GPP.     

Europe's future mobile telephony system

Building on the huge success of its homegrown cellular system, Europe is planning a next-generation wireless system to handle data as well as voice, and-it is hoped-lay the foundation for universal roaming. The system being developed in the framework of the European Telecommunications Standards Institute (ETSI) is called UMTS (Universal Mobile Telecommunication System). In parallel, the International Telecommunication Union, based in Geneva, is formulating IMT (International Mobile Telecommunications) 2000, which is to be a family of systems that will let users roam worldwide with the same handset, and which will include UMTS as a subset     

基于3G网络安全系统的入侵检测研究

3G（第三代移动通信系统）系统的安全是3G系统正常运行和管理的基本保障,3G信息的安全性和网络资源使用的安全性已成为3G网络安全将面临更大挑战。文中给出入侵侵检测（IDS）技术的概念并对入侵检测系统做了描述和分析。入侵检测系统作为信息安全保障中一个重要环节,采用主动防御策略应对3G网络安全面临的威胁和存在的安全问题,最后提出基于3G入侵检测的防范和对策。     

Future Mobile Communications: Evolution or Revolution

Two different approaches towards meeting thefull Third Generation Mobile System (TGMS) requirementsare being discussed extensively in Europe. One ismigration from the GSM-900 DCS/1800 PCk network infrastructure to TGMS (the evolutionaryapproach) and the other is based on the design of a newsystem fully integrated with B-ISDN (the revolutionaryapproach). This paper examines the pros and cons of these two approaches and proposes analternative that consolidates the two approaches into asingle phased one.     

UMTS security

The Universal Mobile Telecommunications System (UMTS) is one of the new 'third generation' mobile cellular communication systems. UMTS builds on the success of the 'second generation' GSM system. One of the factors in the success of GSM has been its security features. New services introduced in UMTS require new security features to protect them. In addition, certain real and perceived shortcomings of GSM security need to be addressed in UMTS. This paper surveys the major security features that are included in the first releases of the UMTS standards.     

基于TDD的HSUPA技术研究进展

高速上行分组接入（HSUPA）是3GPP标准化组织为进一步满足数据业务需求在TD-SCDMA UTRATDD R6版本中提出的一种新技术，描述了引入HSUPA后TD-SCDMA系统的演化，阐述了HSUPA中涉及的物理层混合自动请求重传（HARQ）、快速调度、自适应调制与编码等关键技术及其相应研究，最后讨论了HSUPA技术应用于TD-SCDMA的发展前景。     

WCDMA系统中HSUPA技术的研究

高速上行分组接入（HSUPA）是3GPP标准化组织在WCDMA UTRAN FDD R6版本中提出的一种新技术。文章介绍了WCDMA系统中HSUPA物理层协议结构,重点分析了物理层信道结构,最后讲述了HSUPA中的关键技术。     

A highly digitized multimode receiver architecture for 3G mobiles

A highly digitized multimode receiver architecture is described. It is configured primarily for the Universal Mobile Telecommunication System (UMTS) and Global System for Mobile Communications (GSM) modes, but has the potential to operate in other modes such as cdma2000 as well. The receiver uses a single down conversion to mix the RF signal to a zero intermediate frequency (IF) for UMTS mode and a low IF for GSM. It uses a reconfigurable analog-to-digital converter (ADC) to digitize the IF signals as early as possible and to transfer most of the channel filtering into the digital domain. Only a minimum of automatic gain control (AGC) is employed. The architecture aims to maximize reuse of common hardware and to make significant gains in terms of design costs, size, and adaptability. System simulations confirm the feasibility and performance of the new concept.