Showing papers on "Mobile technology published in 1999"

Next century challenges: mobile networking for “Smart Dust”

Abstract: Large-scale networks of wireless sensors are becoming an active topic of research. Advances in hardware technology and engineering design have led to dramatic reductions in size, power consumption and cost for digital circuitry, wireless communications and Micro ElectroMechanical Systems (MEMS). This has enabled very compact, autonomous and mobile nodes, each containing one or more sensors, computation and communication capabilities, and a power supply. The missing ingredient is the networking and applications layers needed to harness this revolutionary capability into a complete system. We review the key elements of the emergent technology of “Smart Dust” and outline the research challenges they present to the mobile networking and systems community, which must provide coherent connectivity to large numbers of mobile network nodes co-located within a small volume.

Client-server computing in mobile environments

Abstract: Recent advances in wireless data networking and portable information appliances have engendered a new paradigm of computing, called mobile computing, in which users carrying portable devices have access to data and information services regardless of their physical location or movement behavior. In the meantime, research addressing information access in mobile environments has proliferated. In this survey, we provide a concrete framework and categorization of the various ways of supporting mobile client-server computing for information access. We examine characteristics of mobility that distinguish mobile client-server computing from its traditional counterpart. We provide a comprehensive analysis of new paradigms and enabler concepts for mobile client-server computing, including mobile-aware adaptation, extended client-server model, and mobile data access. A comparative and detailed review of major research prototypes for mobile information access is also presented.

Mobile computing and databases-a survey

Abstract: The emergence of powerful portable computers, along with advances in wireless communication technologies, has made mobile computing a reality. Among the applications that are finding their way to the market of mobile computing-those that involve data management-hold a prominent position. In the past few years, there has been a tremendous surge of research in the area of data management in mobile computing. This research has produced interesting results in areas such as data dissemination over limited bandwidth channels, location-dependent querying of data, and advanced interfaces for mobile computers. This paper is an effort to survey these techniques and to classify this research in a few broad areas.

Mobile agents and the future of the internet

Abstract: Use of the Internet has exploded in recent years with the appearance of the World-Wide Web. In this paper, we show how current technological trends may lead to a system based substantially on mobile code, and in many cases, mobile agents. We discuss several technical and non-technical hurdles along the path to that eventuality. It seems likely that, within a few years, nearly all major Internet sites will be capable of hosting and willing to host some form of mobile code or mobile agents.

Mole – Concepts of a mobile agent system

Abstract: Due to its salient properties, mobile agent technology has received a rapidly growing attention over the last few years. Many developments of mobile agent systems are under way in both academic and industrial environments. In addition, there are already various efforts to standardize mobile agent facilities and architectures. Mole is the first mobile agent system that has been developed in the Java language. The first version was finished in 1995, and since then Mole has been constantly improved. Mole provides a stable environment for the development and usage of mobile agents in the area of distributed applications. In this paper we describe the basic concepts of a mobile agent system, i.e., mobility, communication and security, discuss different implementation techniques, present the decisions made in Mole and give an overview of the system services implemented in Mole.

Internet-based mobile ad hoc networking

Abstract: Internet-based mobile ad hoc networking is an emerging technology that supports self-organizing, mobile networking infrastructures. The technology enables an autonomous system of mobile nodes, which can operate in isolation or be connected to the greater Internet. Mobile ad hoc networks (Manets) are designed to operate in widely varying environments, from forward-deployed military Manets with hundreds of nodes per mobile domain to applications of low-power sensor networks and other embedded systems. Before Manet technology can be easily deployed, however, improvements must be made in such areas as high-capacity wireless technologies, address and location management, interoperability and security. The authors give an overview of Manet technology and current IETF efforts toward producing routing and interface definition standards that support it within the IP suite.

Next century challenges: data-centric networking for invisible computing: the Portolano project at the University of Washington

Abstract: Computing and telecommunications are maturing, and the next century promises a shift away from technology-driven general-purpose devices. Instead, we will focus on the needs of consumers: easy-to-use, low-maintenance, portable, ubiquitous, and ultra-reliable task-specific devices. Such devices, although not as limited by computational speed or communication bandwidth, will instead be constrained by new limits on size, form-factor, and power consumption. Data that they generate will need to be injected into the Internet and find its way to the services to which the user has subscribed. This is not simply a problem of ad-hoc networking, but one that requires re-thinking our basic assumptions regarding network transactions and challenges us to develop entirely new models for distributed services. Network topologies will be intermittent and services will have to be discovered independently of user guidance. In fact, data transfers from user interfaces to services and back, will need to become invisible to the user and guided by the task rather than explicit commands. This paper outlines a vision of this future and identifies research problems that will require our attention in the areas of user interfaces, distributed services, and networking infrastructure.

Broadcast protocols to support efficient retrieval from databases by mobile users

Abstract: Mobile computing has the potential for managing information globally. Data management issues in mobile computing have received some attention in recent times, and the design of adaptive braodcast protocols has been posed as an important probllem. Such protocols are employed by database servers to decide on the content of bbroadcasts dynamically, in response to client mobility and demand patterns. In this paper we design such protocols and also propose efficient retrieval strategies that may be employed by clients to download information from broadcasts. The goal is to design cooperative strategies between server and client to provide access to information in such a way as to minimize energy expenditure by clients. We evaluate the performance of our protocols both analytically and through simulation.

A performance evaluation of the mobile agent paradigm

Abstract: This paper presents a performance evaluation of the mobile agent paradigm in comparison to the client/server paradigm. This evaluation has been conducted on top of the Java environment, using respectively RMI, the Aglets mobile agents platform and a mobile agents prototype that we implemented. The measurements give the cost of the basic mechanisms involved in the implementation of a mobile agent platform, and a comparative evaluation of the two considered models (client/server and mobile agents) through two application scenarios. The results show that significant performance improvements can be obtained using mobile agents.

Supporting CORBA applications in a mobile environment

Abstract: CORBA, the Common Object Request Broker Architecture, defines a framework for developing object-oriented distributed applications. Unfortunately, current implementations of CORBA have not been designed with support for mobile computers in mind. Using CORBA in a mobile environment raises a number of problems due to hardware mobility and the characteristics of wireless networks. This paper identifies and discusses these problems and presents the design and implementation of our Architecture for Location Independent CORBA Environments (ALICE). ALICE allows CORBA objects running on mobile devices to interact transparently with objects hosted by off-the-shelf CORBA implementations. Importantly, ALICE allows server as well as client objects to reside on mobile hosts without relying on a centralised location register to keep track of their whereabouts.

SLM, a framework for session layer mobility management

Abstract: This paper describes a novel framework for managing connections to mobile hosts in the Internet. The framework, SLM, integrates the notions of quality of service management and mobility management and forms a base for overall session management. We compare SLM with the currently most widely adopted mobility management framework, Mobile IP, and show how some of Mobile IP's deficiencies are overcome. The paper further presents some initial experimental results and future research.

An architecture for adaptive mobile applications

Abstract: Mobile applications execute in an environment characterized by scarce and dynamically varying resources. We believe that applications have to adapt dynamically and transparently to the amount of resources available at runtime. To achieve this goal, we use the conventional extension of the clientserver model to a client-proxy-server model. The mobile devices execute the client, which provides the user interface and some part of the application logic. The proxy is a component of the application that executes in the wired network to support the client. As the user moves, the proxy may also move to remain on the communication path from the mobile device to a fixed correspondent host. Logically, the proxy hides the “mobile” client from the server, who thinks it communicates with a standard client (i.e., a client that executes on a powerful desktop directly connected to the wired network). The new contribution of our research lies in the division of labor between client and proxy. The application logic of the “standard client” is split dynamically between the mobile client and the proxy, using mobile code, to adapt to the dynamic wireless environment and to address the limitations of the portable device. Using mobile code allows us to experiment with different adaptation strategies and to explore resource tradeoffs in a unified framework. We are developing the components of a flexible and general-purpose runtime infrastructure to facilitate the rapid development and deployment of such adaptive mobile applications. We will evaluate our infrastructure by implementing a number of wireless applications and by building simulation tools to validate the scalability of our architecture when considering metropolitan and provincial cellular systems. The simulations will be driven by trace data that we are collecting in cooperation with a Canadian cellular service provider.

Any Time, Anywhere Computing: Mobile Computing Concepts and Technology

Abstract: Foreword. Preface. 1. Introduction to Mobile Computing. 2. Wireless Telecommunication Networks. 3. Portable Information Appliances. 4. Future Information Appliances. 5. Future Wireless Communication Networks. 6. State of Industry: Mobility Support Software. 7. Research in Wireless and Mobile Computing. Appendices. References. Index.

Power-aware communication for mobile computers

Abstract: The mobile community has focused on techniques for reducing energy consumption for mobile hosts. These power management techniques typically target communication devices such as wireless network interfaces, aiming to reduce usage, and thus energy consumption, of the particular device itself. We observe that optimization of a single device's energy consumption, without considering the effect of the strategy on the rest of the machine, can have negative consequences. We propose power management techniques addressing mobile host communications that encompass all components of a mobile host in an effort to optimize the total energy consumption. Specifically, we propose runtime adaptation of communication parameters in order to minimize the energy consumed during active data transfer. Information about the network environment is used to drive such adaptations in an effort to compensate for the effect of a dynamic service from the wireless communication device on the energy consumed during data transfer. Our results show that power management can often be achieved while maintaining the QoS provided to the application.

Mobile and Personal Communication Systems and Services

Abstract: From the Publisher: Mobile and Personal Communication Services and Systems provides a broad systems overview combined with carefully selected technical details for a clear understanding of the basic technology, architecture, and applications associated with mobile communications. In this book's discussion of mobile telephone, data, and multimedia services, Raj Pandya - international expert in emerging mobile networks and standards - guides telecommunications professionals and students through the past, present, and future of mobile and personal communication systems. He explains how the evolution toward next generation systems will shape tomorrow's mobile communications industry.

Mobile agents protection in the Internet environment

Abstract: The Mobile Agent (MA) paradigm seems to be a promising technology for developing applications in open, distributed and heterogeneous environments, such as the Internet. Mobile agents can overcome some of the limits of the traditional client/server model and can easily integrate with the Web to improve application accessibility. Many application areas, such as electronic commerce, mobile computing, network management and information retrieval can benefit from the application of the MA technology. However, a wider diffusion of MA is currently limited by the lack of a comprehensive security framework. Answering to the requirement of protection for both execution sites and mobile agents can boost the acceptance of the MA paradigm in the Internet environment. The paper describes an MA environment, called Secure and Open Mobile Agent (SOMA), that is based on a thorough security model and provides a wide range of tools and mechanisms to build and enforce flexible security policies. In particular, we focus on the problem of how mobile agents can be protected from malicious behavior of execution sites and we propose a distributed multiple-hops integrity protocol for mobile agent protection, fully integrated in SOMA.

Using code mobility to create ubiquitous and active augmented reality in mobile computing

Abstract: The concept augmented reality is used to describe a system that supplements reality by adding virtual objects into a real-world view. This paper describes a flexible mobile code approach that we can use to implement ubiquitous, active, and mobile augmented reality systems. We will concentrate primarily on solving the problem of how to acquire the data for the virtual objects in a way that will be flexible and expandable enough to be used in truly ubiquitous computer systems. To clarify the concept, we will present an example system that provides virtual user interfaces for various real-world objects. This paper suggests that the mobile code approach offers a relatively simple solution that is flexible, scales well, and does not require the computing equipment attached to the real-world objects to be excessively complicated. We can use the same mobile code approach in applications that provide only simple descriptions of the real-world objects and in complex applications that allow the user to manipulate real-world objects via virtual user interfaces that exist only in augmented reality. Our approach also supports active augmented reality, in which the virtual objects can react to the real-world events.

Mobile Code: The Future of the Internet

Abstract: Use of the Internet has exploded in recent years with the appearance of the World-Wide Web. In this paper, we show how current technological trends necessarily lead to a system based substantially on mobile code, and in many cases, mobile agents. We discuss several technical and non-technical hurdles along the path to that eventuality. Finally, we predict that, within five years, nearly all major Internet sites will be capable of hosting and willing to host some form of mobile agents.

Air interface access schemes for broadband mobile systems

Abstract: High bandwidth everywhere is a key requirement of future communication systems. The big challenge is that the mobile user also be able to benefit. The UMTS, a member of the IMT-2000 family of systems, will offer global universal services up to 2 Mb/s for the mass market in the near future. For users demanding more capacity for "bit-hungry" high-quality applications, broadband mobile radio access systems are being developed, such as wireless LANs and the Mobile Broadband System. In this article broadband mobile systems are classified, taking into account services and quality, spectrum, and standardization issues. The practical experiences gained in two European research projects-ATM Wireless Access Communication System (AWACS) and System for Advanced Mobile Broadband Applications (SAMBA)-are described. Finally, a realistic look at possible future deployment is given.

Mobile Agents as an Architectural Concept for Internet-Based Distributed Applications - The WASP Project Approach-

Abstract: After introducing the concept of mobile agents and potential application domains, we motivate why mobile agent technology is an inter­ esting concept for large Internet-based system structures. We then describe the Java-based WASP agent environment which integrates agent execution platforms into WWW servers and thus promotes a world wide infrastruc­ ture for mobile agents. We sketch first prototype applications, and we men­ tion some unique aspects of the WASP project such as fully transparent migration of Java objects. Finally we report on some experiences we gained when realizing our mobile agent system.

An Evaluation of Real-Time Transaction Management Issues in Mobile Database Systems

Abstract: A critical issue in mobile data management is to respond to real-time data access requirements of the supported application. However, it is difficult to handle real-time constraints in a mobile computing environment due to the physical constraints imposed by the mobile computer hardware and the wireless network technology. In this paper, we present a mobile database system model that takes into account the timing requirements of applications supported by mobile computing systems. We provide a transaction execution model with two alternative execution strategies for mobile transactions and evaluate the performance of the system considering various mobile system characteristics, such as the number of mobile hosts in the system, the handoff process, disconnection, coordinator site relocation and wireless link failure. Performance results are provided in terms of the fraction of real-time requirements that are satisfied.

Mobile Data Access

Abstract: Next generation wireless networks are going to use IP capable mobile terminals and support both voice/multimedia and data services. VoIP is a promising technology allowing a converged core network for all services, and provides a service platform for easier and quicker service creation. Application of VoIP in wireless networks, however, is not so straightforward as people may expect. Among other issues, mobility support is perhaps the most challenging one. The different levels of mobility support (terminal, personal and service mobility) highlight the gap between the existing VoIP framework, which is so far focusing on fixed networks, and the requirements in a wireless environment. After analyzing the existing solutions/proposals for this problem, a framework is proposed in which the mobility-related services are decomposed into several levels so that mobility support is made available to many applications. This layered approach would help to lead to a mobility enabled wireless IP infrastructure in which voice service is just an application.

A survey of mobile data networks

Abstract: The proliferation and development of cellular voice systems over the past several years has exposed the capabilities and the effectiveness of wireless communications and, thus, has paved the way for wide-area wireless data applications as well. The demand for such applications is currently experiencing a significant increase and, therefore, there is a strong call for advanced and efficient mobile data technologies. This article deals with these mobile data technologies and aims to exhibit their potential. It provides a thorough survey of the most important mobile packet data services and technologies, including MOBITEX, CDPD, ARDIS, and the emerging GPRS. For each technology, the article outlines its main technical characteristics, discusses its architectural aspects, and explains the medium access protocol, the services provided, and the mobile routing scheme.

Networking support for mobile computing

Abstract: With increasing use of small portable computers, wireless networks and satellites, a trend to support "computing on the move" has emerged. This trend is known as mobile computing or “anytime” and “anywhere” computing. Some people refer it as “Nomadic” computing. No matter which name is applied, all these terms really imply that a user may not maintain a fixed position in the network. The user is free to roam from one place to another. However the mobile user still expects uninterrupted network access and the ability to run some networked applications. To support such mobility, the user is typically provided a wireless interface to communicate with other fixed and mobile users. The mobile computing environment can be described by the following attributes (a) mobile users, (b) mobile support stations or base stations serving an area, (c) wireless interface, (d) wireless medium with varying channel characteristics (due to fading, noise, interference, etc.) and (e) various applications requiring specific support. A mobile computing environment raises such issues as how to route packets as the mobile user (hosts) moves from one place to the other and how to overcome limitations including limited bandwidth and storage.

Ubiquitous devices united: enabling distributed computing through mobile code

Abstract: A problem with a ubiquitous device like a cellular phone is that it is not properly integrated with contemporary distributed systems. Our goal is to improve this, by enabling cellular phones as interacting clients in a distributed system. We have devised an architecture with two main components: 1) A cellular phone, and 2) a remote extensible server based on a mobile code system. The cellular phone link provides a communication channel to the remote extensible server. This channel is used both for extending remote servers with mobile code and for event notification from remote servers. We have built a prototype weather alarm system, to illustrate the functionality of the architecture. Our prototype system is in daily use, and may be accessed and used by anyone from the World Wide Web.

Design of MOBILE MOM: Message oriented middleware service for mobile computing

Abstract: Message oriented middleware (MOM) is a specific class of middleware that operates on the principles of message passing or message queuing. Existing MOM system doesn't support the function for mobile computing environment. In the near future, requirements of mobile computing will increase and a more dynamic service for mobile computing will be required. And interacting with wireless networks is becoming almost commonplace. In this paper, we propose a MOBILE MOM system supporting mobile computing environment. It is based on an existing MOM system. In MOBILE MOM system, MOBILE MOM applications executed on mobile hosts (MH) dynamically and asynchronously are connected with MOBILE MOM message queue managers executed on fixed hosts (FH) through MOBILE MOM message agents executed on base stations. MOBILE MOM can provide a level of fault-tolerance using persistent queues that allows messages to be recovered when the system fails and very reliable, scalable and performance-oriented distributed application networks in heterogeneous environments.

Protecting mobile Web-commerce agents with smartcards

Abstract: Mobile agents add a new communication paradigm to traditional network communication mechanisms. So far, the pervasiveness of publicly available mobile agent platforms is not given. Offering a seamless integration of mobile agents into the widespread and well-accepted WWW environment is crucial for the success of mobile agents. One of the growing fields of interest in the Web is the area of electronic commerce. Mobile Web-commerce agents could play a prominent role in future electronic commerce scenarios, if the malicious host problem could be solved. Our paper describes the integration of mobile agents into the Web and the use of Java cards to allow a mobile agent to store and securely transport data. This is achieved by allowing the agents to carry encrypted code parts, which can only be decrypted by the Java card attached to the target host of the next migration. Although today's Java cards seem to promise a cheap and secure way to realize a trusted computing base, we found that they introduce specific problems which currently renders them less useful for realizing a trusted computing base for mobile agents.

A method for protecting user data stored in memory of a mobile communication device, particularly a mobile phone

Abstract: The present invention provides a method for protecting user data stored in a memory of a mobile communication device, particularly a mobile phone, comprising the following steps: inputting an identification string; and associating an internal access key with said identification string to provide access to corresponding user data stored in the user data memory (13) of the mobile communication device (10).