从UML状态图到PVS规范的自动转换、验证

将UML(统一建模语言)图形转换成形式化规范是一种精确化UML语义、扩大形式化软件方法适用范围的有效途径.PVS是一种通用高阶逻辑形式化规范语言,具有很强的描述能力以及丰富的定理证明、模型验证工具支持.本文论证了使用.PVS来对UML进行形式化的优势,并且给出了UML的状态图到PVS规范的转换模型与规则.     

摩托罗拉和Freescale将3G带入大众市场

Freescale半导体公司已经被摩托罗拉公司选中来为3G UMTS通信技术开发新的平台解决方案。产品将在2008年进入大众市场。Freescale和摩托罗拉的这一合作将长达4年，共同推动开发3G/UMTS解决方案。从2001年开始的工作目前已经处于领先地位，并将先进的3G／UMTS技术带入了蜂窝市场。     

SIP协议系统模型的形式化研究

通信协议形式化是提高其可靠性和正确性的重要手段.会话初始协议SIP是软交换的一个主要协议,应用形式化方法研究了SIP协议的结构及系统模型,主要从系统级和功能级上使用形式化规格描述语言SDL和消息顺序图MSC对SIP协议主要系统组件进行形式化描述,得到了SIP协议的形式化规范,并应用形式化方法进行了验证.为SIP协议部件库研究开发提供形式化技术基础.     

一种基于学分制排课系统的Z规格说明

运用形式化方法建模在软件开发过程中可提高目标系统的正确性和可靠性,在此提出了一种利用Z语言进行语义分析的方法。该方法在序列图Z规范的基础上,用属性集表示对象状态,并将序列图的上下文表示为Z形式约束,通过检查上下文约束与对象状态间的一致性对序列图进行语义分析。在此以一个基于学分制的排课系统为例,使用面向对象的形式规格说明语言Z,描述了一个精确、完整的高校排课系统的形式化数学模型。过程显示,该方法具有精确的描述性和很强的抽象性,能为软件系统的开发和验证提供科学的框架。     

实验设备管理软件形式化描述方法研究

针对常规的软件描述方法不够严谨,本文介绍了软件形式化方法的特点和技术类别,介绍了Z语言的表达方式及其各自的特点。然后本文使用Z语言分析了实验设备管理软件,给出了部分形式化分析结果。结果表明,Z语言能够将数理逻辑完备用于的描述软件的功能,有效避免描述的模糊性。     

杰尔：Sceptre HPU助力高性能3G设备

从2003年1月起，杰尔系统一直在提供定制的3G手持设备解决方案。2005年1月，杰尔推出了Sceptre HPU双模WGDMA／EDGE、W-EDGE解决方案，并应用于商用产品。使用杰尔系统的Sceptre HPU集成芯片组和软件解决方案，移动设备制造商能够快速、低风险地开发和生产高性能的3G手持设备。与其它3G产品不同，Sceptre HPU是一个集成的W-EDGE解决方案，能够支持四种协议，提供UMTS、EDGE、GPRS和GSM的无缝接入。     

UMTS接入的安全性研究

本文依据3GPP提出的3G安全结构中所重点描述的网络接入的安全技术规范,介绍和分析了UMTS接入的安全机制,并提出将因特网监控使用的入侵检测技术应用到UMTS中,对非法用户的攻击进行防范。     

集成的Z实时扩展RT-Z及其应用模式

将具有状态描述能力的Z语言和具有实序并发描述能力的其它形式化方法如Timed CCS，Timed CSP相结合大大拓展了其在实时并发系统的中的应用能力，不但可以用于需求描述，也可应用于系统设计。在统一语义的背景下使用多种集成方法，其根本目的是适合应用领域的不同特点，本文以RT—Z为基础提出的基本扩展框架对类似集成工作具有普遍意义，最后结合RT—Z的语义集成的分析提出了并发实时系统开发中的一种基本应用模式。     

协议的形式描述与自动实现

协议描述的形式化是协议研究和发展的趋势．本文在简单回顾协议描述的内容和目的之后，着重总结了两个国际性的标准组织ISO和CCITT在协议形式描述方面所进行的工作，对其形式描述语言（ISO的Es－telle和LOTOS语言及CCITT的SDL语言）的结构作了大致介绍；并给出了一个基于形式描述的协议开发环境的系统框架；提出了协议工程学今后研究的重点。     

UMTS接入的安全性研究

根据3GPP提出的3G安全结构中所重点描述的网络接入安全技术规范,介绍了包括双向鉴权、使用临时标识符、UTRAN加密和信令的完整性保护在内的UMTS接入的各种安全机制,提出在UMTS中应用因特网监控入侵的检测技术来防范非法用户的攻击。     

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.     

The Future of Radio Access in 3G

In the last two years, UMTS has progressed from the drawing board to prototypes and pre-release trials. Through the concentrated efforts of manufacturers and operators in the standards bodies, the 3GPP specifications for UMTS, including W-CDMA, TD/CDMA and TD/SCDMA, are currently being developed into deployable equipment for the first UMTS networks. However, human nature dictates that there is always room for improvement, with a constant drive for better performance and higher efficiency. UMTS is by no means the ultimate mobile radio access network, and, even before the first equipment rolls off the production lines, the work of the standards bodies is already looking at enhancements to the system. This paper considers some of these improvements, the evolution of W-CDMA, and the role of TDD in the ongoing developments of third generation mobile radio access.     

A Method for Soft-Decision UMTS Cell Reselection Based on a Database Solution

A novel idea of cell reselection in a UMTS system is presented in this article. The proposed method offers performance enhancements when compared to the algorithm that complies with the 3GPP specifications. This reselection algorithm specifics new criteria that are iteratively computed in every measurement cycle. And to continuously perform the iterative nature of the algorithm, a database solution also is proposed. The database must follow certain rules to maintain the required efficiency.     

Lightweight Secure Roaming Mechanism Between GPRS/UMTS and Wireless LANs

The third generation partner project (3GPP) has standardized general packet radio service (GPRS) and the universal mobile telecommunications system (UMTS) to provide cell phone communications and wireless Internet services. Although the data transmission rate is lower than that of wireless local area networks (WLANs), GPRS/UMTS covers larger areas. Hence, to achieve higher speed ubiquitous access, we propose a lightweight secure roaming mechanism (LSRM) that integrates GPRS/UMTS and WLAN. Taking advantage of these two technologies, LSRM offers anonymous roaming and friendly subscriber management. Besides, we give a formal security analysis to LSRM based on BAN authentication logic.     

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     

Reward-Based Radio Interface Selection of Hybrid 4G UMTS and LTE Communications for Fast Cloud Accesses

For achieving fast accesses the cloud’s big data through mobile smart node, an extreme high data rate for the forwarding link under high-mobility wireless communications is necessary. 3GPP thus specifies LTE/LTE-Advanced specifications as the 4G system to cooperate with the existing UMTS system. To balance loads among different communication interfaces in the hybrid cellular system is one of the most important issues that should be addressed for achieving efficient radio resource allocations. In a shared packet service, the 3GPP UMTS adopts the VSF-OFCDM interface to allocate orthogonal codes of an OVSF code tree in two-dimension spreading of the time and frequency domains. However, UMTS suffers from high packet loss rate and high bandwidth waste rate. In 4G, although the LTE/LTE-Advanced interface offers a high data rate, it suffers from unbalanced loads and moderate reward. This paper thus proposes an adaptive radio interface selection for balancing loads between the UMTS and LTE/LTE-Advanced interfaces according to various interference and mobility environments. Numerical results indicate that the proposed approach outperforms other approaches in fairness, FRL, utilization and call blocking.