Showing papers on "Mobile technology published in 1993"

Mobile computing

Abstract: The problems, limitations, and potential advantages of mobile computing systems are discussed. It is suggested that the constraints violate many of the assumptions upon which today's distributed systems are based. A key requirement of mobile computing systems will be the ability to access critical data regardless of location, which implies interdependence between the elements of a mobile computing system. The Coda file system, which is an effort to provide transparency of environment to mobile computing systems, is reviewed. >

Transaction processing in mobile computing environment

Abstract: Distributed systems are expected to support mobile computations executed over a computer network of fixed and mobile hosts. The authors examine the requirements for structuring such mobile computations that access shared data in a database, argue that open-nesting can better facilitate these requirements, and propose an Open-Nested Transaction model in a mobile environment using the notion of Reporting Transactions and Co-Transactions.

Mobile Wireless Computing: Solutions and Challenges in Data Management

Abstract: Mobile computing is a new emerging computing paradigm posing many challenging data management problems. We identify these new challenges and investigate their technical signi cance. New research problems include management of location dependent data, frequent disconnections, structuring distributed algorithms for mobile hosts, wireless data broadcasting, and energy e cient data access.

Recovery in distributed mobile environments

Abstract: Mobile computing is a rapidly emerging trend in distributed computing. The new mobile computing environment presents many challenges due to the mobile nature of the hosts. The authors present some fault-tolerant data management strategies for a distributed mobile environment. These strategies need to be different from the traditional fault-tolerance approaches because of the resource limitations of mobile computing environment.

System issues in mobile computing

Abstract: The decreasing size of computer components and the increasing availability of wireless communication technology make possible ubiquitous mobile computing: access from anywhere , at any time, to computer networks and the rich set of services attached to them. Mobile computers provide a powerful interface to services that allow a mobile user to access diverse sources of information, exchange electronic messages, interact with other users in real time, and utilize remote computing resources. Previous advances in distributed systems provide a base for such applications, but realizing the full potential of mobile computing requires solutions to new problems. Achieving mobility requires trading performance for weight and power. The hardware weighs less, but is less powerful. To achieve high-performance, mobile computers must utilize wireless networks to access the resources of more powerful but less mobile computers. In addition, moving a computer implies the need for reconnguration at diierent levels of the system. Crossing physical boundaries such as those between buildings requires network reconnguration to provide uninterrupted network access. Crossing administrative boundaries such as those between two divisions of a corporation requires application reconnguration to allow applications to access local services and to cope with security concerns. Realizing the maximum user beneet from mobile computers demands that the system deal with all the above issues. This paper discusses each of these issues in detail, speciically with regard to how they will aaect user applications and how they can be addressed by systems research.

Local area mobile computing on stock hardware and mostly stock software

Abstract: In the Fall of 1992, the graduate Operating Systems class at Carnegie Mellon University implemented the necessary components to provide applications with a programmable interface to a mobile palmtop computer. The goal of the project was to expose project members to the area of mobile computing through "shock immersion." Over the course of two months, students designed and implemented the infrastructure for a simple mobile computing environment for low-end palmtop machines. This programming environment was used to develop a suite of mobile applications such as a mailer, graphical locator map, the game tetris, and a scheme interpreter that allowed functions to be remotely executed on the palmtop. In this paper, we describe the results of the course project and the lessons learned.

A mobile pen-based computing system for cellular telephone networks

Abstract: We propose a mobile computing system based on pen computers and cellular telephones, and develop a prototype system. This system extends the personal office information environment to mobile use. To enable effective use of the conventional cellular telephone network, which has a low data communication speed, we propose new ideas to reduce the data communication traffic between the mobile station and the base station, such as distributed collaborative control, fixed business form manipulation using keywords communication, and a server and a gateway for the mobile station which filter and compress the information sent to the mobile station. The effective use of a pen-based human machine interface is also adopted. E-mail, facsimile, and transaction processing are targeted as the main applications of the system. >

The Westinghouse Series 1000 Mobile Phone: Technology and applications

Abstract: Mobile satellite communications will be popularized by the North American Mobile Satellite (MSAT) system. The success of the overall system is dependent upon the quality of the mobile units. Westinghouse is designing our unit, the Series 1000 Mobile Phone, with the user in mind. The architecture and technology aim at providing optimum performance at a low per unit cost. The features and functions of the Series 1000 Mobile Phone have been defined by potential MSAT users. The latter portion of this paper deals with who those users may be.

Free Trade in a World of Internationally Mobile Technology: The Orthodoxy Then and Now

Abstract: In a recent paper, Kemp and Shimomura extend the basic Heckscher-Ohlin model to show that no country has an incentive to hoard its technology. This basic result is not new. It was first shown by William Ellis in 1825. Ellis extended Ricardo's model to obtain the same free trade result. The history behind these similar theoretical developments is remarkably similar. These writers were responding to increased debates over the benefits of free trade when technologies are mobile between countries. The most widely accepted theoretical models of the time were extended so that policy discussions could be grounded in a strong theoretical base.

Ten questions worth asking about mobile computing.

Abstract: "Mobile," or perhaps "nomadic," are the watchwords for the style of information management fast coming to the healthcare sector. No, mobile technology in healthcare is not to be confused with cellular-phones. Mobile computing goes where the user goes ... to the patient.

IMDNs revolutionize mobile data communications and vehicle location

Abstract: A new breed of intelligent mobile data networks (IMDNs) have set new levels in the mobile arena and are designed to better satisfy the needs of today's mobile communications user. A radio-locating IMDN provides a low-cost, high-performance communications and vehicle location solution for mobile applications. While delivering reliable, high-speed digital data message packets, a radio-locating IMDN provides fast, accurate information on the location of the mobile user. Low-cost equipment and network services will enable more effective management of mobile assets and the growth of new mobile information service offerings.

Data allocation in mobile computing: A project description

Abstract: Users of mobile computers will soon have access to shared online databases via wireless networks. The authors are developing a system that dynamically allocates and deallocates copies of the data-items in these databases to mobile computers, for optimizing cost and performance. This dynamic allocation of data-items to mobile computers is guided by input from the users concerning the type of wireless network, overall system reliability and availability requirements, and the objective function to be optimized.

Key Lessons in Mobile Applications

Abstract: mobile data, cellular data, infra-red cellphone interface, locator This paper describes some of our investigations into mobile applications and proposes a standard interface to mobile phones for computing devices. This interface is based on experience from a number of experimental systems we have built, and outlines the consequent thinking that lead to our proposal for a simple computer interface for mobile communications. The interface is based on the 115kb/s infra-red interface that is being promoted by the Infra Red Data Association [1]. We describe the interface in two ways; one is based on a structural block model, the second uses the OSI model of communications.

Personal mobile communications in microwave band

Abstract: The mobile communications technologies have been extremely-evolved during the past few years. The various types of mobile communications services such as mobile telephone, paging, teleterminal and so-on are in operation in many countries. The analogue cellular system is migrating to the digital cellular system and the high speed data services in the paging system will be launched in the near future. Under those circumstances, the radio spectrum will be lacked in most of countries and the allocation of new frequency band such as quasi-microwave, microwave, and/or millimeter wave will be necessary for the future mobile communications systems. This paper will discuss the technical solution in using the microwave band for the mobile communications area based upon the PHP (Personal Handy Phone) techniques in Japan. And also, the wideband transmission technique for the future multi-media mobile services in the microwave band will be discussed.

Land Mobile Spectrum Efficiency: A Plan for Federal Government Agencies to Use More Spectrum–Efficient Technology

Abstract: The National Telecommunications and Information Administration (NTIA) in the fall of 1992 was required by Congress to develop and commence implementation of a plan for Federal agencies to use wireless mobile technologies that are spectrum efficient and cost effective In response, NTIA performed an analysis of the current Federal land mobile infrastructure with respect to spectrum efficiency and cost effectiveness This report documents the analysis, its results and conclusions, and an implementation plan with recommended milestones The report includes a summary of Federal land mobile requirements and techniques such as Simplex, Repeater, Trunking, Cellular, and Emerging Wireless Technologies The benefits of rechannelization, trunking, and other technical methods to improve spectrum utilization are explained and their spectrum efficiency advantages are quantified Methods to introduce cost effectiveness are also introduced One of these methods is to exploit the economy of scope that exists, for example, if the cost of a single network is less than the cost of several individual networks Policy and regulatory methods that NTIA could use to implement the plan presented in this report include Federal use of commercial vendor services (whenever feasible), and the use of shared systems among government agencies