Showing papers on "Mobile technology published in 1997"

Data management for mobile computing

Abstract: From the Publisher: The focus of Data Management for Mobile Computing is on the impact of mobile computing on data management beyond the networking level The purpose is to provide a thorough and cohesive overview of recent advances in wireless and mobile data management The book is written with a critical attitude This volume probes the new issues introduced by wireless and mobile access to data and what are both their conceptual and practical consequences Data Management for Mobile Computing provides a single source for researchers and practitioners who want to keep current on the latest innovations in the field It can also serve as a textbook for an advanced course on mobile computing or as a companion text for a variety of courses including courses on distributed systems, database management, transaction management, operating or file systems, information retrieval or dissemination, and web computing

Mobile data/message/electronic mail download system utilizing network-centric protocol such as Java

Abstract: In an information distribution system having mobile users, a method of distributing communication channels to mobile users includes transmitting information signals including at least one of Web related information and Internet related information received via one ore more of the Internet, ADSL, another mobile, a land-based user, and the at least one information service provider. The method also includes receiving the information signals from one or more of the Internet, ADSL, another mobile, a land-based user, and the information service provider in the receiver of the mobile terminal, and storing the information signals in its entirety in the mobile terminal prior to broadcasting and/or displaying same to the mobile user. The method also formats, broadcasts and/or displays the information signals after being stored in the mobile terminal.

Mobile IP: The Internet Unplugged

Abstract: Each chapter concludes with a Chapter Summary. I. INTRODUCTION. 1. Introduction. What Is Driving Mobile Communications? What Background Do I Need to Understand This Book? Who Is the Target Audience of This Book? What Is the Purpose of This Book? What Notation Is Used throughout This Book? Are We Talking about IPv4 or IPv6? How Can I Obtain RFCs and Internet Drafts? What Is the Roadmap for the Rest of This Book? 2. Computer Networking Tutorial. How Do Computers Communicate? What Is the Internet Protocol (IP)? How Does IP Routing Work? How Are Routing-Table Entries Created? Why is Routing Based on Network-Prefix? How Can We Translate Names into Addresses? How Can We Determine Link-Layer Addresses? 3. The Need for Mobile. What Happens When a Node Changes Link? Can't You Solve This Problem with Host-Specific Routes? Why Not Just Change the Node's IP Address? Can't You Just Solve This at the Link Layer? What If I Only Need Nomadicity? II. MOBILE. 4. Mobile Overview. Is Mobile an Official Standard? What Problems Does Mobile Solve? What Is the Scope of the Mobile Solution? What Are the Requirements for Mobile? What Are the Design Goals for Mobile? What Assumptions Does Mobile Make? Where Does Mobile Reside? At a 10,000-Foot Level, How Does Mobile Work? 5. Mobile: The Gory Details. What Is the Mobile IP Design Philosophy? What Is Agent Discovery? What Is Registration? How Are Packets Routed to and from Mobile Nodes? 6. Tunneling. What Is IP Fragmentation? What Is IP in IP Encapsulation? What Is Minimal Encapsulation? What Is Generic Routing Encapsulation (GRE)? III. APPLYING MOBILE. 7. Security Primer. What Do We Mean by Security? What Is Cryptography? What Do We Mean by Confidentiality? What Do We Mean by Authentication, Integriy? How Can We Manage Keys Securely? What Security Protocols Are Used in the Internet? What Are Firewalls? 8. Campus Mobility:. What Is the Model for This Application? Insider Attacks Mobile Node Denial-of-Service. Theft of Information: Passive Eavesdropping. Theft of Information: Session-Stealing (Takeover) Attack. Other Active Attacks. 9. Internet-Wide Mobility:. What Is the Model for This Application? Which Threats Are Largely the Same As Before? How Do We Protect a Mobile Node That Is Outside the? How Can Mobile Nodes Traverse the Firewall without? 10. Applying Mobile:. What Is the Model for Commercial, Mobile Service? What Is Theft-Of-Service? Denial-of-Service Revisited. Motorola's iDEN=81: A Case Study. 11. Other Applications for Mobile. Support for Other Protocols within the Mobile. Mobile Networks (as Opposed to Mobile Hosts). Mobile as a Layer-2, Tunnel-Establishment Protocol. IV. FUTURE TOPICS. 12. Mobility for IP Version 6. How Does IPv6 Differ from IPv4? Which of These Differences Is Relevant to the. Doesn't Address Autoconfiguration Eliminate the. How Does Mobile IPv6 Work? How Does a Mobile Node Determine Its Location? How Does a Mobile Node Inform Other Nodes of Its. How Are Packets Routed to and from Mobile Nodes? 13. Open Issues. TCP Performance and Mobility. RSVP and Real-Time Traffic. Service Location. 14. Summary and Final Thoughts. Mobile Summary. The Future of Mobile 307. Glossary. References. Index.

Introduction to Digital Mobile Communication

Abstract: From the Publisher: A thorough introduction to digital mobile communication technology, this book emphasizes digital transmission methods. Beginning with an introduction to what digital mobile communication is, it presents mathematical analyses of signals, mobile radio channels, digital modulation methods and more.

Mobile computing scheme using encryption and authentication processing based on mobile computer location and network operating policy

Abstract: A mobile computing scheme capable of carrying out a proper packet transfer according to a current location of the mobile computer by accounting for the network operating policy. A mobile computer carries out a prescribed communication processing according to recognition results as to whether the mobile computer is located inside or outside the home network at which a mobile computer management device of the mobile computer is provided, and whether or not there exists a packet processing device which has a packet transmitted by at least one of the mobile computer and a correspondent computer as an encryption and authentication processing target. Also, a packet processing device carries out a prescribed transfer processing according to recognition results as to whether at least one of a source computer and a destination computer of a packet to be transferred is a moving mobile computer which is moving outside its home network, and whether or not there exists a packet processing device which has a packet transmitted by at least one of the source computer and the destination computer as an encryption and authentication processing target.

Mobile Code Paradigms and Technologies: A Case Study

Abstract: The opportunities offered by the Internet are encouraging research aimed at the creation of a computational infrastructure that exploits the wide spread communication infrastructure. The mobile computation paradigm is a proposal to build a computational infrastructure that goes beyond the well-known client-server paradigm and increases dynamicity and flexibility. Despite the promising first steps, there is still confusion on the role of paradigms and technology in the development on applications based on the mobile computation paradigm. We present a case study in which we develop several versions of an application using different paradigms and different technologies in order to show when these concepts come into play and which are their relationships.

Certification reports: supporting transactions in wireless systems

Abstract: The emergence of small portable computers and the advances in wireless networking have made mobile computing today a reality. Information systems and databases are among the applications that make mobile computing attractive. While the topic of querying data in wireless and mobile systems has received a lot of attention, techniques to efficiently update data in these systems while providing transaction semantics are not fully developed. We present a novel protocol that uses the broadcast facility to help mobile units do some of the work of verifying if the transactions being run by them need to be aborted. Only when the mobile unit cannot detect any conflict is the server involved in completing the verification. Of course, if the transaction can commit, the server will install the valves in the central database and notify the mobile units (again, using the broadcast channel). The protocol uses a modified version of optimistic control. We study the performance of the protocol by means of a detailed simulation.

Mobile agents: the next generation in distributed computing

Abstract: Mobile agents are programs that can move through a network under their own control, migrating from host to host and interacting with other agents and resources on each. We argue that these mobile, autonomous agents have the potential to provide a convenient, efficient and robust programming paradigm for distributed applications, particularly when partially connected computers are involved. Partially connected computers include mobile computers such as laptops and personal digital assistants as well as modem connected home computers, all of which are often disconnected from the network. We describe the design and implementation of our mobile agent system, Agent Tcl, and the specific features that support mobile computers and disconnected operation. These features include network sensing tools and a docking system that allows an agent to transparently move between mobile computers, regardless of when the computers connect to the network.

Mobile communication method, and mobile telephone switching station customer management system, and mobile unit for implementing the same

Abstract: A mobile communication method suitable for a purchased mobile unit system, a mobile telephone switching station, a customer management system, and a mobile unit A temporary ID, with communication restrictions, such as a limitation on the number of calls, is written into a mobile unit along with a DN, prior to shipment of the mobile unit After purchase, the mobile unit is operated to initiate a registration procedure via a mobile communication network by using the temporary ID and to have a permanent ID written therein By using the temporary ID, a communication connection test can be conducted on the mobile unit prior to shipment from the factory There is no need to install a ROM writer at a mobile unit shop to write personal information

Mobile computing in military ambulatory care

Abstract: Although satellite and cellular communication advances have enabled users of mobile computers the ability to access information regardless of location, it introduces new problems for transaction management in distributed database systems. Traditional transaction mechanisms and criteria have to be adjusted to accommodate the limitations of a mobile computing environment. Data replication is an example of a technique that is used in traditional database systems to increase the availability and the fault-tolerance of the data, but at the same time adds the overhead of maintaining replica consistency across multiple sites of the network. Data replication is a useful tool in mobile computing due to the fact that a mobile host may be disconnected from the network for long periods of time. The data replication allows the mobile host to use a local data copy while it is disconnected from the network. Mobile hosts that have the capability to store copies of data items increase the difficulty of maintaining replica consistency, because of the mobile host's volatile storage. Also, the mobile host must be assured that the local copies that it is using are valid, and any changes made locally to a copy are reflected in the rest of the system. We introduce a mobile replica management algorithm. A mobile transaction manager (MTM) coordinates the transactions initiated by mobile hosts, which query and update replicated databases stated at both mobile and static hosts in a battlefield environment. This battlefield environment is based upon the U.S. telemedicine (Prime Time III) support in Bosnia. The MTM is responsible for the synchronization of the replicated data items in the network.

Designing mobile computing systems using distributed objects

Abstract: This article examines the application of distributed objects to the construction of highly available distributed systems for mobile, ubiquitous computing. High availability for the end user entails the provision of ubiquitous access and flexible resource-sharing. The defining characteristics of mobile computing, such as the frequent movement of users and hosts, the scarcity of network and local computing resources available to the mobile host, and the possibility of disconnections, present difficult challenges in providing high availability for clients in a distributed object system. Meeting these challenges requires dynamic object management techniques in the distributed server architecture on the fixed wired network, as well as object replica management techniques to achieve connection transparency and disconnected operation in the mobile client architecture. Various issues and solutions in constructing a dynamic distributed object-oriented architecture capable of supporting mobile computing are presented.

Supporting mobility with wireless ATM

Abstract: An implicit assumption underlying most networking research has been that two Internet users would be connected only by fixed links (wire lines). Increased use of portable computers, wireless networks and satellites has generated interest in supporting "computing on the move", or mobile computing. Instead of maintaining a fixed position in a network, users in this environment are free to roam. Mobile computing raises interesting issues, such as how to route packets as the mobile user (host) moves about and how to guarantee the quality of service (QOS) that an application running on such a mobile host may need. Other issues include the choice of a transport protocol to use on top of a mobile host and how to deal with poor performance in wireless links. There are two possible approaches to supporting mobile computing over the Internet. The first uses a mobile IP (Internet Protocol), whereby packets (datagrams) are forwarded by a designated stationary host to the mobile host. The second approach involves wireless ATM (asynchronous transfer mode), with host mobility supported by rerouting/rearranging the end-to-end ATM connection between mobile and stationary hosts.

Method and apparatus for low power communications between mobile computing devices

Abstract: A network (10) of mobile computing devices (18) communicates by receiving and rebroadcasting messages using wireless transmission. A message is initiated by first mobile computing device and transmitted to a set of other mobile computing devices which may be selected on an ad hoc basis. The receiving mobile computing devices rebroadcast the message to other of the mobile computing devices (18) which have not received the message. The message is repeatedly rebroadcast until all mobile computing devices (18) have received the message or, if the message is intended for particular selected mobile computing devices (18), until all selected devices have received the message.

Flexible Connectivity Management for Mobile Hosts

Abstract: Powerful light-weight portable computers, the availability of wireless networks, and the popularity of the Internet are driving the need for better networking support for mobile hosts. Users should be able to connect their portable computers to the Internet at any time and in any place, but the dynamic nature of such connectivity requires more flexible network management than has typically been available for stationary workstations. This report proposes techniques to address a unique feature of connectivity management on mobile hosts: its multiplicity, i.e. the need to support multiple packet delivery methods simultaneously and to support the use of multiple network devices for both availability and efficiency reasons. We have developed a set of techniques in the context of mobile IP for flexible, automatic network connectivity management for mobile hosts. We augment the routing layer of the network protocol stack with a Mobile Policy Table (MPT) to support multiple packet delivery mechanisms for different simultaneous flows based on the nature of the traffic. We also devise a set of mechanisms, including a backwards-compatible extension to the routing table, to facilitate the use of multiple network devices. We include performance results showing some of the potential benefits such increased flexibility provides for mobile hosts.

On adaptive caching in mobile databases

Abstract: We consider an environment in which a collection of mobile clients accesses a stationary database server via a wireless channel. Due to the limited bandwidth of a wireless channel and the instability of the wireless network, caching of frequently accessed data items in a client's local storage becomes especially important for improving the performance and data availability of data access queries. However, the network stability and high transmission bandwidth requirements of existing caching mechanisms for conventional clientserver and distributed database applications conflict with the mobility nature of mobile clients as well as the low-bandwidth of wireless channel. In this paper, we investigate issues that need to be addressed in caching mechanisms for a mobile environment and propose an adaptive caching mechanism that could cope with the nature of a mobile environment as well as the low-bandwidth wireless media. The results of some preliminary exploratory experiments will also be illustrated to demonstrate the feasibility of our mechanism.

Security Issues in a Mobile Computing Paradigm

Abstract: In this paper, we discuss operational and security issues arising from the use of mobile components in distributed systems. We argue that mobile agents can be used to overcome intrinsic problems of wireless networking. We define the operational model of our mobile computing environment, where we plan to demonstrate our proposed solutions. We also discuss security problems and mechanisms that can be applied to each one of the three main components of our mobile computing model, which is intended to be implemented in a health care paradigm, where special conditions and emergency needs are imposing the use of services supported with mobile computing.

Mobile object systems : towards the programmable internet : Second International Workshop, MOS '96, Linz, Austria, July 8-9, 1996 : selected presentations and invited papers

Abstract: Mobile computation.- Objectworld.- Commentary on "Objectworld".- Mobile agents: Are they a good idea?.- Mobile agents: Are they a good idea? - update.- A note on distributed computing.- Afterword.- Instruction-based communications.- Analyzing mobile code languages.- Sumatra: A language for resource-aware mobile programs.- Migratory applications.- The messenger environment MO - A condensed description.- Mobility and persistence.- Security and communication in mobile object systems.- Safe and secure execution mechanisms for mobile objects.- Jada: Coordination and communication for Java agents.- Performance-oriented implementation strategies for a mobile agent language.- Dynamic linking for mobile programs.- Adaptive compression of syntax trees and iterative dynamic code optimization: Two basic technologies for mobile object systems.- A type-based implementation of a language with distributed scope.- Interaction of java and telescript agents.

Adaptive caching and refreshing in mobile databases

Abstract: The mobile computing environment is receiving increasing attention recently. We consider a mobile environment in which a collection of mobile clients accesses a stationary database server via a wireless channel. Due to the limited bandwidth of a wireless channel and the instability of the wireless network, caching of frequently accessed data items in a client's local storage becomes especially important for improving the performance and data availability of data access queries. In this paper, we discuss the limitations of existing caching mechanisms in a mobile environment and investigate issues that need to be addressed. We propose an adaptive caching model that could cope with the nature of a mobile environment and the low-bandwidth wireless media, supporting fast data access. We describe the adaptive cache replacement and refresh mechanisms; explain the implementation in the context of object-oriented databases; and illustrate the results of some exploratory experiments to demonstrate the feasibility of the mechanisms.

Database Server Organization for Handling Mobile Clients

Abstract: The use of mobile computers is gaining popularity. The number of users with laptops, notebooks is increasing and this trend is likely to continue in to the future where the number of mobile clients will far exceed the number of traditional \\xed" clients. Applications running on the mobile clients download information by periodically connecting to repositories of data stored in either databases or le systems. Such mobile clients constitute a new and diierent kind of work load and exhibit a diierent access pattern than seen in traditional client server systems. Though le systems have been modiied to handle clients that can download information, disconnect, and later reintegrate, databases have not been redesigned to accommodate mobile clients. There is a need to support mobile clients in the context of client server databases This paper is about organizing the database server to take into consideration the access patterns of mobile clients. We propose a concept of hoard key which captures these access patterns. Three diierent techniques for organizing data at the server based on the hoard key are presented. We argue that each technique is suited for a particular workload. The workload is a combination of requests from mobile clients and traditional clients. This reorganization also allows us to address issues of concurrency control, disconnection, replica control in mobile databases. We present simulation results that show the performance of server reorganization using hoard keys. We also provide an elaborate discussion of issues resulting from this new reorganization in this new paradigm that includes mobile clients and traditional clients.

Utilizing mobile computing in the Wishard Memorial Hospital ambulatory service

Abstract: Advances in cellular technology have permit ted portable computers to communicate with existing static networks. Current transaction mechanisms must be adjusted to accommodate for a mobile host (MH), which can be "disconnected" from the network for long periods of time. In this paper, an architecture for the Wishard Memorial Hospital Ambulatory Service of Indianapolis, Indiana is described. The architecture is based on current mobile models, but with the addition of a base station agent (BSA) which acts as an intermediary for the disconnected MH. The BSA is responsible for the following: commitment of the mobile transaction, storing of t ransact ion results in the mailbox, and recovery. This architecture takes advantage of the existing ambula tory environment by adding a mobile computer that submits transactions to the Indianapolis Network for Patient Care and Research (INPCR), which utilizes the distributed medical database of the Regenstrief Medical Record System (RMRS). Adding a mobile component to the INCPR gives the medical personnel of the ambulatory service the ability to access vital patient information in an efficient manner. A real world example is presented to demonstra te our experiences with mobile computing in this environment. "'Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without lee provided that copies are not made or distributed Ibr profit or commercial advantage and that copies bear lifts notice and the full citation on the first page. Copyrights Ibr components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a tee.'" ¢) I 997 ACM 0-89791-850-9 97 0002 3.50

The Impact of Time and Place on the Operation of Mobile Computing Devices

Abstract: Recent improvements in the quality and reliability of wireless communications has led to the development of a range of mobile computing devices Many portable computers now offer modem connections through cellular and satellite telephone networks Taxi services, emergency vehicles, domestic repair teams all now rely upon mobile links to central computing systems In spite of these advances, a number of technical problems still affect the quality of interaction with mobile applications Electromagnetic interference blocks radio signals Obstacles in the line of sight can interrupt microwave and infra-red transmissions Tracking problems frustrate the use of low-level satellites Transmission delays affect the service provided by higher, geostationary satellites From the users’ point of view, these problems manifest themselves as geographical constraints upon the usability of their ‘mobile’ device This lead to delays in the transmission of critical information These, in turn, lead to the frustration and error that often complicates the operation of mobile computer systems In the short term, it seems unlikely that the technical limitations will be resolved The following pages, therefore, argue that interface designers must consider means of reducing the impact of geographic allocation upon the operation of mobile computing devices

Ubiquitous Computing: Extending Access To Mobile Data

Abstract: iii DEDICATIONS The most important dedication: to Nicole, my wife-to-be, for sticking by me and being so understanding when I was frustrated and grumpy. I'd really like to thank my advisor, Gregory Abowd, for giving such a wonderful opportunity (and a chance to play with cool toys) even though I was only a Masters student. Gregory never once laughed at my ideas, and stuck up for me when I needed it. Of course, if it were up to him, this project would have been called " Newton's AGo Go. " We'll try to ignore that. I'd also like to the entire Future Computing Environments group (I can't name you all) for providing such a fertile playground in which to develop such new and fascinating ideas. My work would have been useless without applications to existing projects. I'm glad I could do my part in furthering their research in ubiquitous computing.

Wireless network extension using mobile IP

Abstract: Over the last two decades, we have seen a dramatic shift in computing systems, away from the monolithic mainframe and toward increasingly distributed, client-server systems. One of the key elements enabling the success of the distributed computing environment was the interconnecting network technology. High-speed, reliable network hardware and protocols evolved to support client-server applications. Network technology has now progressed to the point that applications are being written to specifically exploit the capabilities of the network. The explosion of World Wide Web applications is the latest example of the fact that the network is now the focus of the distributed computing environment. In a concurrent development, personal computing platforms placed increasingly powerful systems in ever smaller form factors. Users have embraced these advances: Mobile computers, in the form of laptops, palmtops, and personal digital assistants (PDAs), are a significant element of the current computing environment. However, to be fully productive, the mobile computer user requires access to the network. Further, access to a network is not sufficient. Mobile users need access to the same network-the same resources and services and communications capabilities-that they would if they were at their desktops. We refer to this concept of providing home network access to the mobile user as network extension. Addressing many requirements for practical wireless access, this Internet technology aids the development of advanced data services for wireless networks, including the integrated dispatch enhanced network.

Mobile Computing: When Mobility Meets Computation

Abstract: —————————— ✦ —————————— One of the most challenging and interesting recent trends in the computer and telecommunications industries is the integration of mobile communications and computing. The resulting distributed network, referred to as a mobile computing system, is in more that one way fundamentally different from conventional wired computer networks. Wireless connectivity enhances the functionality of computing equipment by freeing communication from the location constraints of the wireline infrastructure. By changing this basic characteristic, mobile computing systems operate on a set of assumptions made by traditional computing systems, requiring researchers and users to redefine their model of networked computing. The successful use of mobile computing faces several challenges, among them:

Support for mobile pen-based applications

Abstract: We describe a general software architecture employing handheld comnuters, that provides pen-based interfaces to existing graphical applications that‘ were designed with a conventional mouse-based interface. This architecture allows delivery of computationally intensive applications to mobile users, and is flexible enough to accommodate interface devices with a wide range of capabilities. To illustrate the functionality of the architecture, we describe a system that we have constructed which is based on the architecture.

Multimodal Interfaces for Cell Phones and Mobile Technology

Abstract: By modeling users' natural spoken and multimodal communication patterns, more powerful and highly reliable interfaces can be designed that support emerging mobile technology. In this paper, we highlight three different examples of research that is advancing state-of-the-art mobile technology. The first is the development of fusion-based multimodal systems, such as ones that combine speech and pen or touch input, which are substantially improving the robustness and stability of system recognition. The second is modeling of multimodal communication patterns to establish open-microphone engagement techniques that work in challenging multi-person mobile settings. The third is new approaches to adaptive processing, which are able to transparently guide user input to match system processing capabilities. All three research directions are contributing to the design of more reliable, usable, and commercially promising mobile systems of the future.

Mobile Agents: First International Workshop, MA '97, Berlin, Germany, April, 7-8, 1997, Proceedings

Abstract: An agent-based approach for quality of service negotiation and management in distributed multimedia systems.- Exploiting code mobility in decentralized and flexible network management.- Java-based mobile agents - How to migrate, persist, and interact on electronic service markets.- Mobile code paradigms and technologies: A case study.- The architecture of the ara platform for mobile agents.- A multi-agent architecture supporting services access.- Contracting and moving agents in distributed applications based on a service-oriented architecture.- Concordia: An infrastructure for collaborating mobile agents.- The OMG mobile agent facility: A submission.- Mobile agents - Smart messages.- Communication concepts for mobile agent systems.- Mobile agent interaction in heterogeneous environments.- Strategically mobile agents.- A novel mobile Agent search algorithm.- Insisting on persistent mobile agent systems.- Open resource allocation for mobile code.- A distributed transaction model based on mobile agents.- A toolset for architecture independent, reconfigurable, multi-agent systems.

MINOTAURUS: A Distributed Multimedia Tourism Information System

Abstract: The rapidly expanding technology of mobile computers, wireless data networks, vehicle navigation, multimedia and database systems has caused the development of powerful mobile information systems. These systems, consisting of a portable computer (Laptop, PDA), have large storage capacities, capabilities of wireless connection to a worldwide information network and provide to their users many functionalities like access to WWW, shopping, banking, reservations and other transactions.