Evaluating the benefits of multimodal interface design for CoMPASS—a mobile GIS

The context of mobility raises many issues for geospatial applications providing location-based services. Mobile device limitations, such as small user interface footprint and pen input whilst in motion, result in information overload on such devices and interfaces which are difficult to navigate and interact with. This has become a major issue as mobile GIS applications are now being used by a wide group of users, including novice users such as tourists, for whom it is essential to provide easy-to-use applications. Despite this, comparatively little research has been conducted to address the mobility problem. We are particularly concerned with the limited interaction techniques available to users of mobile GIS which play a primary role in contributing to the complexity of using such an application whilst mobile. As such, our research focuses on multimodal interfaces as a means to present users with a wider choice of modalities for interacting with mobile GIS applications. Multimodal interaction is particularly advantageous in a mobile context, enabling users of location-based applications to choose the mode of input that best suits their current task and location. The focus of this article concerns a comprehensive user study which demonstrates the benefits of multimodal interfaces for mobile geospatial applications.     

保留细节特征的轮廓线远程绘制算法

目前,智能掌上电脑、个人数字助理和智能手机等移动终端因为其便携性和可移动性,越来越多地被应用于分布式虚拟环境中,但是因为移动终端自身的局限性,在移动终端上的3维模型实时绘制问题仍未得到很好的解决。结合多分辨率网格模型和基于轮廓线的远程绘制的优点,提出了一种保留细节特征的轮廓线远程绘制算法。该算法预处理阶段,在原始精细网格模型上提取细节特征线,并进行多分辨率网格模型的预处理;运行时阶段,根据视点、帧率等交互信息使用选取策略对细节特征线进行选取,然后构建合适的多分辨率网格模型,并在该模型上提取出外围轮廓线,最后发送这两种轮廓线到移动终端进行绘制。实验结果表明,该算法在基于轮廓线的远程绘制中较好地保留了模型的细节特征,并保证了在移动终端的实时绘制。     

一种自适应的ICN移动性机制

信息中心网络（information-centric networking,ICN）内在地支持兴趣请求者移动而不支持内容提供者移动,然而在实际的场景中往往发生的是内容提供者移动。当前的移动性解决方案存在一些缺憾,如没有真正地考虑移动设备的加入/离开、机制过于单一不能应对各种移动场景、网络切换时延过长等。为解决上述问题,面向区域划分设计一种自适应的移动性机制,包括基于汇聚点的域内移动解决方案、基于兴趣转发的域间移动解决方案和基于回溯的基站间移动解决方案。仿真在GTS网络拓扑上进行,实验结果表明所提的移动性机制较基准机制有高的分发率、低的切换时延和少的路由跳数,说明所提的移动性机制具有广泛的应用价值,为推动诸如5G应用的全面落地具有现实的意义。     

Service Orientation in the Enterprise

A new trend gaining momentum in recent years is companies' use of mobile devices as an integral part of their IT infrastructure for both employees and customers. Although similar to early Web-based products, mobile services have technical and physical limitations. However, they also enjoy the advantage of location independence, whereas existing PC-based solutions can offer, at best, a nomadic context. Corporate employees as well as consumers can clearly perform tasks more efficiently when stationary, but they can execute a growing number of functions with acceptable or even superior efficiency using mobile devices. This capability usually evolves in a three-stage process. In the first stage, a given task cannot be performed using a general-purpose mobile device, although the desire exists and dedicated single-purpose mobile devices are available. In the second stage, general-purpose mobile devices start providing the ability to perform the task in mobile contexts, but this choice remains secondary to a stationary solution. In the third stage, users prefer to carry out the task with a mobile device even if a stationary option is available.     

From desktop to mobile: Examining the security experience

The use of mobile devices is becoming more commonplace, with data regularly able to make the transition from desktop systems to pocket and handheld devices such as smartphones and PDAs. However, although these devices may consequently contain or manipulate the same data, their security capabilities are not as mature as those offered in fully-fledged desktop operating systems. This paper explores the availability of security mechanisms from the perspective of a user who is security-aware in the desktop environment and wishes to consider utilising similar protection in a mobile context. Key issues of concern are whether analogous functionality can be found, and if so, whether it is offered in a manner that parallels the desktop experience (i.e. to ensure understanding and usability). The discussion is supported by an examination of the Windows XP and Windows Mobile environments, with specific consideration given to the facilities available for user authentication, secure connectivity, and content protection on the devices. It is concluded that although security aspects receive some attention, the provided means generally suffer from usability issues or limitations that would prevent a user from achieving the same level of protection that they might enjoy in the desktop environment.     

Mobile situation-awareness within the project map

Mobile devices as PDAs evolve rapidly from digital calendars and address books to hosts of more complex functionality. Mobile access to business information such as customer, product or project databases is seen as one of the cutting edge IT solutions for improving productivity and customer satisfaction. However, mobility and scaled-down mobile technology lead to specific limitations in contrast to the usage of desktop computers. These restrictions are absolutely crucial to consider for the development of usable mobile applications.

With reference to the project map—Multimedia Arbeitsplatz der Zukunft (Multimedia Workplace of the Future), this article outlines our main approach to situation-aware support for mobile workers in response to mobile restrictions. We are pointing out focal components and sketch parts of the map architecture, in particular the prototypical application “BuddyAlert”.     

Mobile IPv6 and the future of wireless Internet access

Wireless technology is increasingly being used for Internet access and other IP-based communications. To make it easier for wireless users to exploit this trend, the Internet Engineering Task Force (IETF) designed Mobile IP version 4 in 1996. However, MIPv4 has not been deployed widely enough to provide much mobility and has several major shortcomings, including a cumbersome communications process and a limited number of IP addresses. The latter is a key problem because the number of mobile devices that need their own IP address to access the Internet is increasing rapidly. To overcome these deficiencies and introduce new capabilities, the IETF has been developing MIPv6. MIPv6 makes many more IP addresses available and lets mobile users stay connected to the Internet as they move between networks. The paper discusses MIPv6 implementation.     

基于SIP的移动性管理

几个无线技术论坛,比如3GPP2,已经决定采用SIP作为移动因特网会话管理的信令协议,很显然SIP将成为移动因特网协议结构中不可分割的一部分。详细描述了怎样使用SIP对终端和个人移动性的支持。移动IP虽然使得移动性对更高层是透明的,但是它也带来了三角路由和隧道管理等问题,而SIP在应用层对移动性进行管理,对于实时通信来说,这种方案更加有效。     

A resource aware software partitioning algorithm based on mobility constraints in pervasive grid environments

Pervasive computing suffers from resource limitations of mobile devices, while grid computing can utilize almost unlimited resources distributed in the whole Internet. The conjunction of such two paradigms generates a new promising one, called pervasive grid computing, where mobile users can use handheld devices to access abundant resources and services in the grid. In this paper, a novel software partitioning algorithm is presented, which is suitable for pervasive grid to optimally allocate software components between a mobile device and one or more servers, with the goal of saving the resources of mobile devices. The algorithm takes into account component mobility constraints to not only prevent violating execution requirements of the application, but also to fully exploit component mobility, replication and rebinding to conserve more resources as compared to previous works. Another distinguishing feature of the algorithm is its generality, which can be applied to minimize network bandwidth usage, response time and energy consumption, respectively or simultaneously. Extensive simulation results have demonstrated the validity and effectiveness of the proposed algorithm in various environments.     

The SATIN Component System-A Metamodel for Engineering Adaptable Mobile Systems

Mobile computing devices, such as personal digital assistants and mobile phones, are becoming increasingly popular, smaller, and more capable. We argue that mobile systems should be able to adapt to changing requirements and execution environments. Adaptation requires the ability-to reconfigure the deployed code base on a mobile device. Such reconfiguration is considerably simplified if mobile applications are component-oriented rather than monolithic blocks of code. We present the SATIN (system adaptation targeting integrated networks) component metamodel, a lightweight local component metamodel that offers the flexible use of logical mobility primitives to reconfigure the software system by dynamically transferring code. The metamodel is implemented in the SATIN middleware system, a component-based mobile computing middleware that uses the mobility primitives defined in the metamodel to reconfigure both itself and applications that it hosts. We demonstrate the suitability of SATIN in terms of lightweightedness, flexibility, and reusability for the creation of adaptable mobile systems by using it to implement, port, and evaluate a number of existing and new applications, including an active network platform developed for satellite communication at the European space agency. These applications exhibit different aspects of adaptation and demonstrate the flexibility of the approach and the advantages gained     

Using RSS feeds for effective mobile web browsing

While mobile phones are becoming more popular, wireless communication vendors and device manufacturers are seeking new applications for their products. Access to the large corpus of Internet information is a very prominent field. However, the technical limitations of mobile devices pose many challenges. Browsing the Internet using a mobile phone is a large scientific and cultural challenge. Web content must be adapted before it can be accessed by a mobile browser. This work presents a new methodology that uses Really Simple Syndication (RSS) feeds for the adaptation of web content for use in mobile phones. This methodology is based on concrete design guidelines and supports different viewing modes. The mobile tool provided using the RSS feeds is evaluated based on user-centered evaluation and the results are presented.     

Personalised code generation from large schema sets for geospatial mobile applications

XML and XML Schema are used in the geospatial domain for the definition of standards that enhance the interoperability between producers and consumers of spatial data. The size and complexity of these geospatial standards and their associated schemas have been growing with time reaching levels of complexity that make it difficult to build systems based on them in a timely and cost-effective manner. The problem of producing XML processing code based on large schemas has been traditionally solved by using XML data binding generators. Unfortunately, this solution is not always effective when code is generated for resource-constrained devices, such as mobile phones. Large and complex schemas often result in the production of code with a large size and a complicated structure that might not fit the device limitations. In this article we present the instance-based XML data binding approach to produce more compact application-specific XML processing code for geospatial applications targeted to mobile devices. The approach tries to reduce the size and complexity of the generated code by using information about how schemas are used by individual applications. Our experimental results suggest a significant simplification of XML Schema sets to the real needs of client applications accompanied by a substantial reduction of size of the generated code.     

Delay tolerant lazy release consistency for distributed shared memory in opportunistic networks

Opportunistic networks (ONs) allow mobile wireless devices to interact with one another through a series of opportunistic contacts. While ONs exploit mobility of devices to route messages and distribute information, the intermittent connections among devices make many traditional computer collaboration paradigms, such as distributed shared memory (DSM), very difficult to realize. DSM systems, developed for traditional networks, rely on relatively stable, consistent connections among participating nodes to function properly.We propose a novel delay tolerant lazy release consistency (DTLRC) mechanism for implementing distributed shared memory in opportunistic networks. DTLRC permits mobile devices to remain independently productive while separated, and provides a mechanism for nodes to regain coherence of shared memory if and when they meet again. DTLRC allows applications to utilize the most coherent data available, even in the challenged environments typical to opportunistic networks. Simulations demonstrate that DTLRC is a viable concept for enhancing cooperation among mobile wireless devices in opportunistic networking environment.     

网络移动代理系统的新型安全技术

网络的普及为发展新技术提供了基石,这些新技术能为我们带来服务的深入和使用的便利。移动代理算法是一种新型的技术,能整合网络中的计算资源以满足新应用的需求。目前学术界和产业界都对移动代理技术非常关注。然而,移动代理的安全问题严重阻碍了其发展和应用。这篇论文介绍了移动代理系统的安全隐患及其相应的解决方案,分析了各种方案的优势和缺陷。在应用方面,分析了一些目前比较普及的移动代理系统,比较了其安全方案的不同侧重点,提出了关于未来移动代理系统发展的思考。     

Engineering mobile agent applications via context-dependent coordination

The design and development of Internet applications requiring dynamic and possibly mobile access to Internet resources can take advantage of an approach based on autonomous mobile agents. However, mobility introduces peculiar issues related to the modeling and management of the agents' coordination activities. This paper introduces context-dependent coordination as a framework for the design and development of Internet applications based on mobile agents, and shows how it can be supported by a proper coordination infrastructure. Context-dependent coordination is centered on the notion of programmable coordination media, as the software abstraction via which an agent in an Internet site can access to local resources and coordinate with local agents. Programmability stems from the fact that the behavior of the media can be fully configured to influence agents' coordination activities. This enables local administrators to configure coordination media so as to enact site-dependent coordination policies, and mobile agents to configure the accessed coordination media to obtain an application-dependent behavior of the media themselves. Several application examples shows that exploiting context-dependent coordination promotes a clear separation of concerns in design and development, and can make applications more modular and easier to be maintained. The MARS system is assumed as an exemplar coordination infrastructure to clarify the concepts expressed and to show their actual implementation.     

Patterns of Mobile Interaction

The design of systems for mobile scenarios covers a wide range of issues, ranging from mobile networking to user interface design for mobile devices. Mobile applications often run distributed on several connected devices, used by many users simultaneously. Considering all issues related to mobile scenarios, a designer might be overwhelmed. As a solution, we propose a specific kind of design patterns which we call mobility patterns, derived from successful mobile applications. They allow a designer to re-use design elements as building blocks in their own designs. After describing the idea of mobility patterns, we give a brief overview of patterns we have identified so far. Two patterns are described in more detail with the help of our research platforms QuickStep and Pocket DreamTeam.     

Mobile cinema: canonical processes for video adaptation

Nowadays, users not only want to watch digital videos on a PC but also use mobile devices to play back multimedia content. Video adaptation algorithms enable the visualization of recorded videos on mobile devices. Based on our Mobile Business system, we have developed a video adaptation application called Mobile Cinema which considers several characteristic features of mobile devices like screen resolution, bit rate or color depth of a display. The functionality of this system is high and it would be much easier to understand the system if the analysis and the design of the algorithms and the communication interfaces are based on predefined processes which we call canonical processes for media production. The definition of these processes would also make the comparison of two video adaptation applications or the exchange of modules between different systems much easier. In this paper, we describe the functionality and requirements of our existing video adaptation application and map them to the canonical processes for media production.     

面向富互联网应用的计算任务动态迁移机制

富互联网应用(rich Internet application,RIA)目前已经成为重要的应用模式.随着信息技术日益泛在化和服务化,富互联网应用也开始在移动设备之上运行.然而,由于设备计算能力的不足,很可能出现部分代码无法在富客户端顺利运行的情况.提出面向富互联网应用的计算任务动态迁移机制,在应用运行过程中,动态地将...     

Mobile networking through Mobile IP

Mobile IP is a proposed standard protocol that builds on the Internet Protocol by making mobility transparent to applications and higher level protocols like TCP. Mobile IP (RFC 2002) is a standard proposed by a working group within the Internet Engineering Task Force; it allows the mobile node to use two IP addresses: a fixed home address and a care-of address that changes at each new point of attachment. The article presents the Mobile IP standard in moderate technical detail and points the reader toward a wealth of further information. Is also describes how Mobile IP will change with IP version 6, the product of a major effort within the IETF to engineer an eventual replacement for the current version of IP. Although IPv6 will support mobility to a greater degree than IPv4, it will still need Mobile IP to make mobility transparent to applications and higher level protocols such as TCP. There is a great deal of interest in mobile computing and apparently in Mobile IP as a way to provide for it. A quick Web search for items related to Mobile IP returned over 60,000 hits-impressive even given the notorious lack of selectivity for such procedures. Mobile IP forms the basis either directly or indirectly of many current research efforts and products. The Cellular Digital Packet Data (CDPD), for example, has created a widely deployed communications infrastructure based on a previous draft specification of the protocol. In addition, most major router vendors have developed implementations for Mobile IP