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.     

从GSM到UMTS的网络演进

先对通用移动通信系统（UMTS）以及向UMTS演进过程中的一些主要技术进行简单介绍,然后着重介绍从GSM到UMTS的核心网和无线网的网络演进。     

分组数据业务:从GSM到UMTS

本文主要介绍了分组数据业务在GSM(GPRS)网及其第三代系统UMTS中的发展情况,分析了它们的系统结构和无线接口协议栈,讨论了移动通信中分组模式与Internet的结合———移动IP在第三代系统中的应用。     

GSM to UMTS — Architecture Evolution to Support Multimedia

This paper outlines the launch architectures for UMTS and its evolution from GSM. It then carries on to discuss the issues and solutions to evolve this towards a truly open architecture to enable the delivery of multimedia, mass-market speech a IP friendly data communications within the third generation mobile environment.The drivers and requirements for the architecture evolution are explained along with the steps and approaches being taken within the various developments of IP, GPRS and multimedia.     

Efficient two-port antenna system for GSM=DCS=UMTS multimode mobile phones

The design of several two-port antenna systems for mobile phones is presented. All these structures are made up of two planar inverted-F antennas closely positioned on a small ground plane and radiating in the GSM900/DCS1800 and UMTS frequency bands. First, the antennas are simply associated at the top edge of the same printed circuit board. Thus, to improve their isolation and their total efficiency, a neutralisation effect is created by means of an optimised suspended line, which links the feeding strips of the radiators. The performance of these systems is measured and compared with theoretical results     

A pre‐emption framework for UMTS compatible satellite system supporting multimedia traffic

The pre‐emption procedure is an important part of the radio resource management when dealing with the emergency traffic. It allows resources to be allocated to higher priority connections by pre‐empting lower priority connections. The provision of the pre‐emption mechanism becomes much more important in the case of satellite systems such as the Inmarsat Broadband Global Area Network system, which aids in providing the communication during a catastrophe. This paper focuses on the pre‐emption framework for a Universal Mobile Telecommunications System‐based satellite systems. Three algorithms have been proposed, Greedy, SubSetSum and Fuzzy pre‐emption algorithm. Extensive simulations are carried out for the three algorithms, and their performances are compared against each other. Simulation results show that the Fuzzy pre‐emption algorithm performs better than the other two algorithms. Copyright © 2014 John Wiley & Sons, Ltd.     

On the UWB system coexistence with GSM900, UMTS/WCDMA, and GPS

This paper evaluates the level of interference caused by different ultra-wideband (UWB) signals to other various radio systems, as well as the performance degradation of UWB systems in the presence of narrowband interference and pulsed jamming. The in-band interference caused by a selection of UWB signals is calculated at GSM900, UMTS/wideband code-division multiple-access (WCDMA), and Global Position System (GPS) frequency bands as a function of the UWB pulsewidth. Several short-pulse waveforms, based on the Gaussian pulse, can be used to generate UWB transmission. The two UWB system concepts studied here are time hopping and direct sequence spread spectrum. Baseband binary pulse amplitude modulation is used as the data modulation scheme. Proper selection of pulse waveform and pulsewidth allows one to avoid some rejected frequency bands up to a certain limit. However, the pulse shape is also intertwined with the data rate demands. If short-pulses are used in UWB communication the high-pass filtered waveforms are preferred according to the results. The use of long pulses, however, favors the generic Gaussian waveform instead. An UWB system suffers most from narrowband systems if the narrowband interference and the nominal center frequency of the UWB signal overlap. This is proved by bit-error rate simulations in an additive white Gaussian noise (AWGN) channel with interference at global system for mobile communication (GSM) and UMTS/WCDMA frequencies.     

GSM和UMTS网络安全性的比较研究

随着移动通信系统的发展,业务应用越来越丰富,对移动通信安全性的要求也越来越高.虽然在GSM系统中已经开始引入鉴权和数据加密机制,以提高移动通信系统的安全性,但还不够完善,比如没有提供数据完整性保护的功能,用户无法对网络进行鉴权,不能很好地支持安全性要求较高的业务等.在UMTS系统中定义了五个方面的安全特性,覆盖了所有可能的信息交换的接口,并通过切实有效的机制弥补了GSM系统中的安全隐患,增强了网络的安全性.     

Congestion control for multimedia services

The problem of congestion control in high-speed networks for multimedia traffic, such as voice and video, is considered. It is shown that the performance requirements of high-speed networks involve delay, delay-jitter, and packet loss. A framing congestion control strategy based on a packet admission policy at the edges of the network and on a service discipline called stop-and-go queuing at the switching nodes is described. This strategy provides bounded end-to-end delay and a small and controllable delay-jitter. The strategy is applicable to packet switching networks in general, including fixed cell length asynchronous transfer mode (ATM), as well as networks with variable-size packets     

Policy-based QoS architecture in the IP multimedia subsystem of UMTS

The third-generation mobile system, or Universal Mobile Telecommunication System, will offer IP-based multimedia applications and services with end-to-end QoS guarantee. The key part providing these services is the policy-based QoS control architecture in the IP multimedia subsystem (IMS). In this tutorial we describe the network entities involved in the policy-based QoS architecture, their interactions to realize guaranteed QoS in the UMTS network, and the communication interfaces employed in the interactions.     

Interactive multimedia services to residential users

Despite the business risks involved in the introduction of digital video and interactive television, vigorous investments made by the telecommunication industries and content owners clearly demonstrate the belief that such services are going to happen. In this paper, a complete scenario for the provision of interactive multimedia services from the residential user's point of view is considered, focusing on software components. Initially, a reference architecture configuration, based on the DAVIC paradigm, suitable for the provision of residential interactive broadband services is presented. In addition to hardware capabilities, the system will be considered successful only if it is easy to learn, worth the time and cost-effective. Consequently, a set of possible service requirements is introduced and a development process for distributed interactive multimedia applications is proposed. Finally, based on experience gained from the implementation of applications in different residential trials throughout Europe, guidelines and methodologies for user interface design are illustrated     

UMTS/GSM混合网络中的安全问题研究

在2G向3G演进的过程中，GSM与UMTS将在很长时间内共存，它们构成了混合网络结构。本文讨论混合网络结构的若干安全问题。首先，讨论混合网络结构的认证与密钥协商过程；然后针对混合网络结构中业务的系统间交互问题进行一些讨论。     

基于GSM/UMTS网络的ETC接入性能评估

为了更好地评估分析ETC业务在GSM/UMTS现网上的适应承载性,文章首先建立了ETC三层业务源模型,并结合相应的模型对ETC和传统H2H业务共存于GSM/UMTS网络场景下的接入性能分别进行评估分析。仿真结果表明,ETC业务能够在不明显影响H2H业务接入性能的条件下,较好地承载在现有GSM/UMTS网络上。另外,仿真结果表明多流业务场景2与多流业务场景1相比,能够更好地承载ETC业务,对实际应用有着很重要的指导价值。     

采用GSM引擎模块实现GSM增值业务

GSM网络经过多年的发晨,已经比较成熟,但是随着新一代移动通信网络的建设与试运营,GSM网络面临着GPRS和CDMA的巨大挑战。如何充分利用现有的GSM网络资源,发挥网络覆盖率高、用户数量大等忧势,开展多种增值业务,越来越为GSM网络运营商所重视。 短消息（Short Message）是GSM系统提供给用户的一种数字业务。短消息业务分为两种:一种是点对点短消息（SMS-PP）,在用户之间传送信息;另一种是小区广播短消息（SMS-CB）,类似于现在的寻呼,定期在一定的区域内重复广播交通流量、天气状况等信息,不同于寻呼机的是短消息是一种双向通讯。GSM系统提供的短消息业务可以让网络端知道被叫方是否收到所发的消息。如果传迭失败,被叫方没有回答确认消息,网络会保留所传的消息,一旦网络发现被     

UMTS, the mobile multimedia vision for IMT 2000: a focus onstandardization

Cellular mobile telecommunications and the World Wide Web are growing at an exciting pace. In the year 1999 both GSM and the Internet reached more than 200 million registered users globally. Thus, it may be expected that users will demand the combination of mobility and multimedia services in a foreseeable time frame. Multimedia content increases and differentiates with the changing information society, and an even richer variety of audio, visual, and text-based information will be required in the future. UMTS, the Universal Mobile Telecommunications System, a member of the IMT-2000 family of third-generation systems, will provide these services. UMTS standardization has set a new paradigm of timely market-driven standardization in a global partnership of standardization bodies     

UMTS分组域与GSM/GPRS系统间切换过程中数据缓存与转移的实现与分析

首先介绍了UMTS中的几种切换类型,然后就UMTS分组域到GSM/GPRS系统间切换(SGSN间),GSM/GPRS到UMTS分组域系统间切换(SGSN间),UMTS分组域到GSM/GPRS系统间切换(SGSN内),GSM/GPRS到UMTS分组域系统间切换(SGSN内)这4种切换过程中的数据缓存与转移的实现过程进行了详细论述,并进行了进一步深入的分析与比较,最后指出其优缺点。     

A proposal of an ATM wireless access system for tetherless multimedia services

This paper proposes an ATM wireless access system for tetherless multimedia services. The proposed system is intended to provide ATM-based high-speed transmission capability for tetherless multimedia services by wireless media in private LAN/WAN environments as well as public environments. To enable high-speed transmission, this paper proposes the utilization of the SHF band taking advantage of its wide frequency spectrum availability. However, the propagation feature of the SHF band limits the wireless terminal mobility in the proposed system compared with current cellular phone systems. This paper discusses the concept and system architecture of the proposed ATM wireless access system, including its ATM transport based on ATM/TDMA conversion using a time stamp scheme.     

Coupled-fed Printed PIFA for Internal Eight-Band LTE/GSM/UMTS Mobile Phone

A coupled-fed printed PIFA （Pla- nar Inverted-F antenna） for eight-band operation cov- ering the LTET00/2300/2500 and GSM850/900/1800/ 1900/UMTS2100 bands in the mobile phone is presented. The proposed antenna comprises a driven W-mouopole and two coupled folded-strips. The folded strip which is coplaner with the T-monopole is called strip 1 and the folded-strip on the back of the system circuit board is called strip 2. The strip 1 is short-circuited to the system ground through an inductance and the Strip 2 is short-circuited to the system ground plane of the mobile phone directly. The driven T-monopole and the strip 1 contribute a wide band for the antenna＇s upper band （1710-2690MHz）, whereas the strip 2 generates a resonant mode for the anteuna＇s lower band （698-960MHz）. The antenna＇s two wide op- erating bands are achieved and controlled by tuning the width of the T-monopole, the gap g3 between the strip 1 and the T-monopole, and the dimensions of the strip 2 on the back of the system circuit board. Details of the pro- posed antenna are described, and the obtained results are presented and discussed.     

Providing multimedia communications services from high altitude platforms

System level design considerations for high altitude platforms operating in the mm‐wave bands are examined. Propagation effects in these bands are outlined, followed by a brief introduction to different platform scenarios. Ground‐based and platform‐based fixed wireless access scenarios are considered, and it is shown that using a platform, a single base station can supply a much larger coverage area than a terrestrial base station. The effects on performance of platform displacement from its desired location with both fixed and steerable antennas are also examined. It is shown that steerable antennas are of most use when fixed stations are immediately below the platform, with no benefit for fixed stations on the edge of coverage. The bandwidths required to serve several traffic distributions (suburbs and city centre based) are evaluated using the Shannon equation. It is shown that capacity can be constrained when users are located in the city centres, despite longer line of sight paths to users out in the suburbs. The effects of temporal changes in the spatial traffic distribution are investigated. It is shown that bandwith requirements can be reduced if the platform moves to track these changes. Copyright © 2001 John Wiley & Sons, Ltd.