一种基于移动代理的新型网管接口一致性测试模型的研究

为解决传统的网管接口测试方法中存在的智能性和灵活性不够等缺点,文中提出了针对网管的接口一致性测试模型,将移动代理技术应用到网络管理的测试中,着重体现了一种新型的网管测试技术。     

The AROUND Architecture for Dynamic Location-Based Services

This paper presents a generic concept of location-based service as an abstraction for supporting the association between computational resources and location. The objective is to extend the advantages of service-based architectures to the development of location-based systems, thus providing a more open and extensible alternative to the vertical approaches typically used in this type of system. The novel AROUND architecture is proposed as an approach for supporting location-based services in the Internet environment. AROUND provides a service location infrastructure that allows applications to select services that are specifically associated with their current location. The architecture includes a flexible scope model that defines the association between services and location, and a service location infrastructure organised by spatial criteria and optimised for location-based queries. Based on a prototype implementation of this architecture, we have developed two case studies that illustrate the use of this approach for developing location-based systems. The overall results provide a valuable insight into the applicability of the architecture, and suggest that this model of location-based services can provide a useful approach for the development of a wide range of location-based applications.     

Attempts to Exchange Iron into H-Y and H-ZSM-5 Zeolites by in situ Formed Chloride-Containing Mobile Species

Three variants of solid-state ion exchange were studied. Iron exchange was found to proceed in the first case, in theFeCl₂+NH₄ZSM-5 FeZSM-5 + NH₄Cl process, even at low exchange capacity (Si/Al = 25).The second, Fe₂O₃ (hematite) + HZ direct reaction does not result in any noticeable interaction for eitherZ = Y or ZSM-5. This process can significantly be promoted by introducing CCl₄ vapor via forming chlorine-containingmobile species. However, the structure of the Y zeolite largely collapses during this treatment, whereas the crystalline state of ZSM-5is preserved.     

Replication Requirements in Mobile Environments

Replication is extremely important in mobile environments because nomadic users require local copies of important data. However, today's replication systems are not mobile-ready. Instead of improving the mobile user's environment, the replication system actually hinders mobility and complicates mobile operation. Designed for stationary environments, the replication services do not and cannot provide mobile users with the capabilities they require. Replication in mobile environments requires fundamentally different solutions than those previously proposed, because nomadicity presents a fundamentally new and different computing paradigm. Here we outline the requirements that mobility places on the replication service, and briefly describe ROAM, a system designed to meet those requirements.     

Mobility Management for Hierarchical Wireless Networks

In this paper, we consider the mobility management in large, hierarchically organized multihop wireless networks. The examples of such networks range from battlefield networks, emergency disaster relief and law enforcement etc. We present a novel network addressing architecture to accommodate mobility using a Home Agent concept akin to mobile IP. We distinguish between the physical routing hierarchy (dictated by geographical relationships between nodes) and logical hierarchy of subnets in which the members move as a group (e.g., company, brigade, battalion in the battlefield). The performance of the mobility management scheme is investigated through simulation.     

移动环境公平支付协议的设计与分析研究

结合固定网络中的支付协议并充分考虑移动装置和无线网络的特点,提出了一种移动环境公平支付协议。利用模型检验工具对协议进行分析并将该协议与其他支付协议进行比较,分析和比较结果表明,该协议具有公平、保密、高效等特点,适用于移动环境。     

多媒体无线网中QoS降级的公平性研究

对无线，移动多媒体网中多服务类、多优先级的适应多媒体应用QoS降级的公平性问题进行了研究。提出降级因子加权平方和最小的降级原则，不但考虑了类间和类内优先级，而且考虑了用户的QoS降级深度。接着，证明对离散型适应多媒体应用，降级因子加权平方和最小的降级原则满足广义的按比例公平性，而对连续型适应多媒体应用，满足按比例公平性。最后，用量子遗传算法对所给问题进行了求解，结果进一步验证了所提算法的有效性。     

新颖的移动代理动态数据完整性保护协议

通过引入攻击者能力来对完整性的强弱进行划分和定义，在此基础上，分析了合谋情况下对动态数据进行截断攻击的问题，并给出了一个新颖的移动代理数据保护协议，该协议通过引入反向签名机制，形成一条从源节点到当前节点的信任链，实现对漫游路径的完整性保护，很好地解决了合谋情况下对动态数据的截断攻击，为自由漫游移动代理提供了更强的完整性保护。还使用形式化方法对协议的安全属性进行了分析验证。     

无线数据增值业务平台垄断与竞争商务模式

商务模式，乏移动商务的重要研究内容之一，随着无线数据增值业务的快速发展，人们发现开放或封闭的商务模式都可以找到成功和不太成功的案例。首先对中间平台商务模式的组织架构进行了定性的讨论，然后在建立理论模型的基础上对无线数据增值业务平台商务模式中开放和封闭的组织结构对平台利润的影响进行了比较分析，给出了不同商务模式所适用的不同条件。     

DS-CDMA卫星通信系统线性多用户检测算法性能比较

CDMA是新一代移动通信系统的关键技术,现代卫星移动通信也采用CDMA技术。多址干扰(MAI)的存在严重影响了CDMA系统的性能,需要采用多用户检测技术进行抑制。本文分析了卫星移动通信系统的模型,将线性多用户检测算法用于卫星移动通信系统,并对传统检测器、解相关检测器、MMSE检测器等线性检测器进行了性能比较。计算机仿真结果表明采用线性多用户检测技术使卫星移动通信系统的性能得到了明显的改善。