Applying IP over wmATM technology to third generation wirelesscommunications

With the rapid development of third-generation wireless mobile communication systems worldwide, the wireless mobile ATM enhanced software radio platform has taken the lead in the implementation process, which helps construct a broadband wireless pipe and “IP over wmATM” open signaling suite to support various common air interfaces for the wireless industry. This article presents the implementational issues using the IP over wmATM solution for 3G broadband wireless mobile communication systems. It includes the design of the wmATM medium access controller, protocol stack, wmATM module definition, and software radio platform, as well as IP unified 3G wireless networks     

Reverse high-speed packet data physical layer enhancements in cdma2000 1/spl times/EV-DV

The rapid growth of Internet-based applications calls for design of a high-speed wireless packet data communication system. This anticipated increase in future mobile wireless packet data services has challenged the current 3G standardization bodies to respond with evolved 3G system specifications capable of providing increased data throughput. In response to such a need, 3GPP2 recently completed the enhanced reverse link standardization effort of the CDMA technology flagship, cdma2000/spl reg/ by completing the definition of the 1/spl times/EV-DV 1/spl times/ system. 1/spl times/EV-DV achieves higher data throughput while simultaneously providing coexisting and backward-compatible voice services within the same spectrum. This feature of 1/spl times/EV-DV allows wireless operators to manage the voice and data loading in their system more efficiently. This article describes the physical layer reverse link enhancements in cdma2000 revision D that are necessary to support 1/spl times/EV-DV.     

未来移动通信系统中的无线资源管理

文章结合当前正在研究的后3代(B3G)、第4代(4G)移动通信系统的发展和处于运营及推广阶段的第3代移动通信系统,分析了未来移动通信系统中无线资源管理系统的关键技术,探讨了多体制标准下的无线通信网络和多种业务情况下的无线资源管理的研究方向。     

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.     

宽带无线网络中的纠错编码

随着高速多媒体业务的迅速发展,如何提高第三代移动通信系统（3G）以及新一代移动通信系统（Beyond3G）的性能和容量愈发受到人们的重视。在业务无线接入时的服务质量（QoS）问题上,高效的纠错编码是必不可少且行之有效的解决方法之一。文中简要回顾了纠错码在前两代移动通信中的应用,并着重介绍了目前的研究热点——Turbo码和LDPC码的研究现状及发展前景。     

3G系统安全技术研究

文章介绍了第3代移动通信系统的安全结构，包括网络结构、功能结构；讨论了第3代移动通信系统的空中接口安全保护技术，包括数据螂性保护、数据完整性保护。     

Packet scheduling in 3.5G high-speed downlink packet access networks: breadth and depth

Forecasts for emerging mobile device markets anticipate that bandwidth will be squeezed by demanding applications like multimedia on demand. This will spur the need for data rates beyond what the upcoming 3G wireless cellular systems such as UMTS can offer. To boost the support for such high data rates, HSDPA, labeled as a 3.5G wireless system, has been introduced in Release 5 of UMTS technical specifications. HSDPA is a definite step toward meeting the "anywhere, anytime, and in any form" 4G communication concept. HSDPA promises a peak data rate of up to 10 Mb/s, five times larger than the data rate offered by 3G systems. In order to support such high data rates, HSDPA relies on many new technologies, among which is packet scheduling. In this article we provide breadth and depth related issues of packet scheduling in HSDPA, discuss state-of-the-art HSDPA scheduling algorithms in terms of their objectives, advantages, and limitations, and suggest further research issues that need to be addressed. In addition, we propose a packet scheduling algorithm for data traffic in HSDPA. Simulation results demonstrate the effectiveness of the proposed algorithm     

Cell search algorithms for the 3G long-term evolution

This article presents downlink initial synchronization and cell identification algorithms for long term evolution (LTE) of third-generation (3G) mobile communication systems, which are based on synchronization channel (SCH) and cell specific pilot symbols, respectively. The key features of the proposed scheme are: it can improve performance of the frequency synchronization through oversampling of the SCH, it can support a large number of target cells by modulating a cell-specific pilot sequence over two symbols within a subframe, and it can guarantee cell identification performance by maximally ratio combining the frequency domain differential cross-correlation. Simulations show that the proposed scheme has a potential use in 3G LTE.     

移动宽带无线接入技术(MBWA)前瞻

移动宽带无线接入技术(IEEE802.20)是无线宽带接入技术的一种,相对802.11和802.16系列,其覆盖范围更广,业界认为它是第三代移动通信系统(3G)的竞争者。文章对其性能特性、业务及应用、网络架构、接口及协议分层进行论述,并与802.16和3G进行比较,展望其发展前景。     

Access network evolution beyond third generation mobile communications

Second-generation mobile radio systems have been deployed successfully worldwide. These systems have evolved to higher data rates and packet transmission. Third-generation mobile radio systems are currently being standardized worldwide to be initially deployed in 2001 and 2002 in different regions of the world. New advanced multimedia services are under development, and first services are already being offered in second-generation systems, which will provide new business opportunities. Already today discussion is starting on the development of systems beyond third-generation mobile radio systems due to the long timeframe for system specification and international standardization. However, today there is no clear vision available on such systems. This discussion takes into account the new deregulated and liberalized communication environment. This article presents a concept for a system beyond third-generation mobile radio systems, which comprises a combination of several optimized access systems in a common IP-based medium access and core network platform. These different access systems will interwork through horizontal and vertical handover, service negotiation, and global roaming. The different access systems are allocated to different mutually complementing cell layers in the sense of hierarchical cells with respect to cell size, coverage, and mobility to provide globally optimized seamless services to users. This vision requires extensive international research and standardization activities to solve many technical challenges. Key issues are the global interworking of different access systems on a common platform, advanced antenna concepts, and the implementation of multimode and multiband terminals and base stations through software-defined radio concepts.     

The design policy for a GSM-based IMT-2000 network

The third-generation mobile network has been a topic of considerable interest worldwide and has begun to be commercialized throughout the world. The 3G mobile network has evolved from two types of 2G networks; one type has evolved from GSM and another from ANSI-41. We operate the Personal Digital Cellular network as a 2G network and have designed a GSM-based IMT-2000 network as a 3G network. This article gives our design policy for the GSM-based IMT-2000 network and the technology that enabled us to develop the network based on this policy (e.g., ATM switching in the core network). Furthermore, the foundations for 2G/3G dual network operation (e.g., number portability and succession of 2G services in a 3G network) and efficient transition from a 2G network to a 3G network are also considered.     

A Study of the Simulation Platform of WCDMA

1　IntroductionAtpresent,manydifferentsystemshavecoex istedinthedevelopmentofmobilecommunication .Thingshavegotmorecomplexinthedevelopmentof3Gthanever.Inadditiontothecoexistenceofmul tiplemobileschemes,anothercomplexityisthatthe3Gmustbecompatiblewiththe 2Gsystems.Soft wareDefinedRadio (SDR )orSoftWareRadio(SWR)isakindofnewwirelesscommunicationtechnology .Ithasbeenrecognizedasthenextmajorleapforwardinmobilecommunications.Particular ly ,itisabletoprovidetheseamlessconnectionbe tweenmanyex…     

A tutorial on multiple access technologies for beyond 3G mobile networks

In this article, some fundamental technical concepts of the main multiple access schemes for wireless mobile systems are reviewed, and a path for the development of appropriate multiple access technologies for next-generation mobile networks, or so-called beyond 3G (B3G), is established. We first review the multiple access technologies in second- and third-generation wireless cellular systems from historical and technical points of view. This review is followed by a novel formulization of the multiple access schemes through mathematical expressions that could simplify the process of development of new multiple access schemes for B3G wireless cellular systems. We then list the most important features of multiple access schemes in 3G mobile systems. Finally, we conclude the article by reviewing the most promising multiple access technologies for B3G mobile cellular systems     

TD-CDM-OFDM: Evolution of TD-SCDMA toward 4G

TD-SCDMA, which is the "homemade" 3G standard in China, has received considerable attention and is believed to play a critical role in the development of China's mobile communication. Meanwhile, advanced MIMO and OFDM techniques shed light on the feasibility of high-performance 4G broadband systems. We discuss an evolutionary path of TD-SCDMA toward 4G systems in this article, which combines the existing advanced traits in TD-SCDMA with new features for broadband wireless communication systems.     

The 3G-324M protocol for conversational video telephony

As mobile operators worldwide migrate to third-generation (3G) networks, conversational video-telephony services are becoming a key differentiator between new 3G offerings and existing 2G/2.5G services. Although it's possible to have limited video-based services - such as a multimedia messaging service - that deliver pictures and video clips over 2.5G services, these are delay-insensitive applications that could run over a packet-based wireless network like general packet radio service (GPRS) or code division multiple access (CDMA)'s 1XRTT. For delay-sensitive applications such as conversational video telephony, present 3G packet bearers are inadequate, and the Third Generation Partnership Project (3GPP; http://www.3gpp.org) mandates using the 3G bandwidth-guaranteed circuit-switched bearer and the 3G-324M system. The 3G-324M system is a derivative of the International Telecommunication Union (ITU) H.324 protocol standard for low-bitrate multimedia communication, which ITU-T developed for the public switched telephone network (PSTN). This article describes the 3G-324M system, which has been adopted by both 3GPP and 3GPP2 (htpp://www.3gpp2.org), as well as its H.324 roots.     

IPRAN部署方案研究

随着移动通信2G向3G技术的演进,以话音为主的移动业务向着话音和数据业务并重的方向发展,移动互联网的新型业务以及电信运营商的全业务拓展需求推动着移动业务和承载网络的IP化进程。本文介绍了IPRAN的发展背景,对关键问题进行了分析。同时,对主流的IPRAN技术做了一定的介绍;特别针对PTN的技术原理以及组网策略进行了论证。在此基础上,讨论了全业务运营环境中,如何以IP RAN作为切入点来构建一个融合承载移动、视频及宽带等综合业务的承载网络架构。最后,通过某电信运营商的实际网络部署策略方案为案例,对IPRAN网络部署策略做一定阐述。     

Balance-fed planar built-in antenna

A planar built-in antenna with a balance-fed configuration, denoted a balance-fed planar inverted-F antenna (BPFA), has been developed for the IMT-2000, third-generation (3G) mobile communication system. The BPFA features balanced operation, which leads to a significant reduction in the current induced on the telephone body and therefore the absence of any significant effect caused by the operator's hand     

移动通信技术的发展、回顾和展望

本文首先回顾了２０世纪移动通信技术发展的历程，介绍了第三代移动通信技术研究和标准的进展情况，最后讨论了今后移动通信技术发展趋势和特点。     

COST 231 achievements as a support to the development of UMTS: alook into the future

An overview has been given of the current trends in the field of mobile communications, with specific reference to the European environment; in particular, the COST 231 organisation and activities during its first five years of life have been outlined, emphasizing the major results obtained so far and their potential impact on current or proposed third-generation mobile communication systems. Relationships established with other projects or regional and international standardization bodies have been pointed out, and special attention has been given to the activities envisaged for the near future     

File transmission over wireless fast fading downlink

The third-generation code division multiple access (3G CDMA) mobile communication networks are designed to transmit voice and data over wireless channels. Fundamental problems need to be solved for such mobile communication networks to operate efficiently. One of the problems is finding optimal scheduling algorithms for file transmission over the fading downlink channel from a base station to mobile users. Here, the problem is solved in the case of transmission of a given number of files. Optimal algorithms that minimize the delay and the transmission time are found. Also, specific nonoptimal algorithms are considered and compared numerically with the optimal ones. We consider a slotted downlink with channels to the mobile users that are dependent in the same slot but independent for different slots. Additionally, some generalizations are presented.