Showing papers on "GSM published in 1989"

The provision of GSM cellular radio environments within passenger aircraft operating over Europe

Abstract: The author describes the findings of a feasibility study into the means of provision of a GSM cellular radio environment inside passenger aircraft. The background and capacity estimates for such a system are discussed prior to the presentation of a description of proposed system architecture. This description includes topics such as network organisation, handover, transmission delay compensation, signalling, the RF link and the aeronautical transponder implementation.

Speech processing in the pan-European digital mobile radio system (GSM)-system overview

Abstract: A digital cellular mobile radio system has been under development in Europe since 1982, under the coordination of the CEPT (European Conference of Post and Telecommunications Administrations) working group GSM (Groupe Special Mobile). Among the crucial issues in the design of this system were the development of a low-bit-rate speech codec and voice-activated transmission scheme. After a brief review of the historical background, an overview of the system is provided, with particular emphasis on the factors that interacted with the design of the speech processing functions, e.g. access and transmission methods, error protection, and network organization. >

Radio transmission interface of the digital panEuropean mobile system

Abstract: The author describes the radio interface format of the cellular pan-European public mobile communications system in the 900-MHz band. This format was selected after comparing experimental hardware based on different radio access techniques as well as different modulation and coding schemes. A description of the radio interface specification is also presented, together with the expected performance in terms of frequency reuse. Hardware results from measurements of a validation system built in France according to this specification are also presented. >

Modelling and simulation of the propagation characteristics of the 900 MHz narrowband-TDMA CEPT/GSM mobile radio

Abstract: The authors examine the problem of modelling and simulating the propagation characteristics for the pan-European digital mobile radio system, as specified by CEPT/GSM (Conference Europe des Postes et des Telecommunications/Group Special Mobiles). The modelling problem is solved by means of the time- and frequency-dependent linear filter (TFLF) identified by its transfer functions and representative of the short-term random propagation processes. Starting from such a TFLF and from the power delay profiles specified by CEPT/GSM, the simulation model provides independent realizations of the mobile radio channel transfer function. Particular attention is also devoted to the model calibration. Finally, an example of performance analysis is shown, considering a typical communication channel of the CEPT/GSM system using a reduced-complexity Viterbi adaptive equalizer, based on a modified Viterbi algorithm, and with timing and carrier phase recovery and channel impulse response estimation performed by utilizing the 26-bit 'midamble' sequence foreseen by the TDMA (time-division multiple-access) channel burst format. >

Combined space/time diversity technique for narrowband TDMA mobile radio systems

Abstract: A new diversity technique is presented which employs antenna (space) diversity in conjunction with time staggering to allow the receiver to collect energy from several paths without phase or gain adjustments. The technique is particularly suited to narrowband TDMA where the receiver is likely to include an equaliser, and the resulting performance gains are characterised, taking the GSM system as an example.

Implementation aspects of the pan-European digital mobile radio system

Abstract: In 1991 a digital mobile radio system, the so-called Group Special Mobile (GSM) system, will be introduced in Europe. The author presents the modulation and coding techniques which have been standardized recently For the GSM. for the baseband processing algorithms of speech coding, channel coding, and adaptive equalization, VLSI requirements are addressed. The new system has been designed for a capacity of about 10 million subscribers in Europe. Hand-held pocket telephones are expected to play a major role. The typical requirements are weight 24 h, and active operation >1 h. A major problem is the reduction of the power consumption, which requires that certain functions be switched off in the standby mode. >

Prospects for a common air interface for cellular and cordless systems

Abstract: Market forces will eventually force cellular and cordless systems to converge into one integrated network having the virtues of both cellular and cordless systems. The eventual universal mobile telecommunication system (UMTS) would be a federation of systems with a common but flexible air interface. The authors compare the air interface functions of cellular and cordless systems. The GSM and DECT air interface implementations are taken as examples of cellular and cordless air interfaces respectively. They identify those functions which can have common solutions and those which require dual solutions for the two modes. This work was undertaken as part of the RACE mobile project. They also mention some of the techniques being investigated.

A new design method for microwave cascade networks

Abstract: An efficient method for the analysis and design of microwave cascade devices is presented. Complete control of electrical and geometrical parameters, together with the possibility of minimizing a cost function gradually imposed, permits the synthesis of sophisticated microwave components. The generalized scattering matrix (GSM) of a cascade network is computed using a new recursive formula. A cascade of discontinuities is computed starting from the GSM of the load and going back, step by step, to the source until the last discontinuity is reached. A comparison between the proposed method and the classic GSM approach is given. A novel network synthesis procedure is described, comparing the proposed method with other procedures in the design of a circular polarizer in a square waveguide. >

From TACS to GSM

Abstract: This paper provides a background into the decisions taken on GSM, its basic features and the approach Cellnet is adopting to respond to the introduction of digital cellular into an analogue environment. This approach resides in a step-by-step approach through usage of validation and pre-operational equipment with the clear requirement at each stage of equipment which not only responds like a GSM system but actually contains hardware that is realised from the recommendations.

Realization of a Distributed Data Base in the European Mobile Radio Telephone System

Abstract: The GSM Recommendations give the standards for a Pan-European mobile radio telecommunication system. The Location Registers form a Distributed Data Base whose interworking with other entities of the GSM System provides an integrated directory function. The properties and functionality of the GSM Location Registers and the implementation of the Distributed Data Base in the system “ECR 900” are described.