Showing papers on "Mobile technology published in 1989"

Introduction to mobile communications

Abstract: Mobile radio plays a very important role within the commercial, business and public safety sectors in almost all industrialized parts of the world. It is generally recognized as one of the most efficient ways to increase effectiveness, reduce operating costs and preserve energy. Growth has been rapid over the past few decades, and the provision of adequate radiofrequency spectrum to meet the increasing demand for licences is of primary concern to national radio regulatory administrations both in the long and short term. For many years, however, the continued demand for channels has not been matched by a corresponding increase in the amount of spectrum available. The allocation of a frequency band near 900 MHz for cellular mobile radio and the release of part of Band III (174-225 MHz) for trunked mobile radio systems in the UK has helped to ease the short-term problem, but there is evidence that even these bands will soon become congested, particularly in the major conurbations, and further action will be necessary.

Mobile Network Architecture

Abstract: The Mobile Network Architecture (MNA) is designed to provide a cohesive, consistent framework for the development of a new generation of mobile data communications systems. This new generation of systems is required to meet the varying needs of current and future users, providing integrated support for the development, attachment and operation of diverse mobile applications. This paper describes the form and function of the three component architectures of the MNA, and how these components provide service to the users of an integrated mobile data network. The Communications Architecture, which is based upon the CCITT Open Systems Interconnection reference model, supports a layering of communications services and protocols for mobile data transport. The Operations, Administration and Maintenance Architecture, which is derived from the ISO OSI Management Framework, facilitates centralized management and control of a mobile network. Finally, the Applications Architecture, which uses a transaction-based model derived from experience with existing mobile applications, supports user applications in the harsh mobile environment.

DATAMOVIL: a practical implementation of TRADAMO mobile data transmission protocol

Abstract: The DATAMOVIL system has been developed for use by security forces, computer-aided dispatchers, and wherever an application requires highly reliable voice and data communications for a mobile fleet. A protocol called TRADAMO has been implemented as a key part of this system. This mobile data transmission protocol is presented along with the ASIC (application-specific integrated circuit) that implements part of it. The system allows a large reduction in the mean air time required for a mobile user by channeling part of the voice traffic as status message traffic, and also allows transparent data transmission between mobiles and host computers, even in the field. >

Mobile stone-cleaning machine

Abstract: The stone-cleaning machine cleans all common paving stones in situ (even clinkers), where they have been taken up and are to be laid again. With the cleaned stones, laying as they were laid before is made possible again. By the adjusting possibilities of the guiding frame and the nozzles, all types of stones can be optimally cleaned, with the minimum expenditure of air.