Showing papers on "GSM published in 1992"

The GSM System for Mobile Communications

Abstract: From the Publisher: This book is out-of-print, and a new second edition will be released by the end of 2002. The digital standard known as the Global System for Mobile (GSM) has captured a large share of the global cellular market. This book aims to bridge the gap between a reader’s basic knowledge of telecommunications and the complexities of the 5000-page GSM technical specification. It describes the system as a whole, covering all aspects of the standard, including mobile stations, switching equipment, the radio interface, infrastructure, transmission methods, and signaling protocols. System architects involved in the design of personal communications systems will find the book to be a complete description of the GSM communications system. It also may serve as a general introduction to digital cellular systems.

Method for relaying information in an integrated services network

Abstract: A method to be implemented in an integrated services network, such as the well known ISDN, GSM or CMS88 type networks, takes advantage of short message service technology to enable communication between terminal equipment units, i.e., between people using the network. This method makes possible (a) the use of a short message service to provide automatic answer transmission; (b) the use of a specified memory area, from which the content of the automatic answer transmission is automatically fetched; and (c) the storing, in advance, within the specified memory area, of any useful information for any potential caller, i.e., a calling subscriber. The calling subscriber will in turn automatically receive information, e.g., on how to reach the person not attending the terminal device for the moment, or any other such useful information. The short message service scheme permits the sending of short messages from a call originating device to a call terminating device, even when the user of the call terminating device is not answering the call.

Method in mobile telephone systems in which a subscriber identity module (sim) is allocated at least two identities which are selectively activated by the user.

Abstract: Method in mobile telephone systems, especially of the GSM type, in which a subscriber identity module (SIM) is allocated at least two identities (IMSI 1, IMSI 2) which are selectively activated by the user. A preferred embodiment of a subscriber identity module consists of an active card which can be inserted in two different positions corresponding to one and the other identity, respectively. Preferably, the positions pertain, respectively, to one and the other end of the card.

The use of SS7 and GSM to support high density personal communications

Abstract: The authors present an organized method for quantifying the Signaling System 7 (SS7) traffic load associated with terminal mobility when the pan-European standard GSM is used for personal communication networks (PCNs). They use CCIR parameters for an extremely dense, outdoor center-city pedestrian environment to illustrate the possible heavy signaling load. Using the example parameters, the additional SS7 network burden is 4-11 times greater for cellular than for ISDN and 3-4 times greater for PCN than for cellular, depending on the visitor location register placement. The numerical results are very sensitive to assumptions on user mobility, cell size, and location area size. This highlights the need for careful investigation of these parameters in specific applications. >

A comparison of CDMA and TDMA systems

Abstract: Two candidates for high-capacity cellular systems are simulated and analyzed, one code-division multiple access (CDMA) and one time-division multiple access (TDMA) system Simulations of the CDMA example indicate a high sensitivity to variations in certain system parameters The TDMA example is a GSM system using random frequency hopping and operating without frequency planning The simulations show that the TDMA system has at least the same capacity as the CDMA candidate Soft capacity, efficient use of voice activity, and diversity are features available in both systems >

Simulation and performance of the pan-European land mobile radio system

Abstract: The introduction of the European Telecommunications Standards Institute/Groupe Special Mobiles (ETSI/GSM) digital land mobile radio system has required the study and application of advanced transmission techniques, necessary to meet the quality objectives in very demanding environments. In particular, the authors consider the performance of the compact-spectrum constant-envelope modulation chosen by ETSI/GSM, together with concatenated block and convolutional coding, Viterbi adaptive equalization, and soft-decision Viterbi decoding to cope with the severe time- and frequency-selective distortions caused by propagation phenomena, properly modeled for computer simulation. Channel coding and adaptive equalization techniques, supported also by frequency hopping and diversity reception, are fundamental to operate the system with the required quality. >

Method for carrying out a location updating from a mobile cellular radiophone system to another cellular radiophone system

Abstract: A method for carrying out a location updating from a mobile cellular radiophone system, such as a DECT system, to another cellular radiophone system, such as the GSM mobile phone system In order to enable trunking of an incoming call to a terminal of a mobile system and also to obtain such a method for carrying out the location updating as ensures, as well as possible, a compatible information content in the networks, the method includes the following steps: (a) when the location area of the other system changes, the change is signalled to the mobile system, (b) an instruction is transmitted from the mobile system via radio path to the terminal of the mobile system to initiate an internal update procedure of the mobile system, and the internal update procedure of the mobile system is carried out in which the terminal of the mobile system transmits to the mobile system an indication of its presence, which step (b) is carried out in respect of at least one terminal of the mobile system, (c) the internal update procedure of the other radiophone system is carried out by the mobile station of the other radiophone system in respect of the at least one terminal of the mobile system, and (d) the procedure is continued from step (b) in respect of the terminals of the mobile system not yet updated

The Pan-European Digital Cellular Mobile Radio System - known as GSM: 1st

Abstract: A flat still camera wherein a hollow section of the housing is reciprocable relative to the main section to thereby actuate the shutter and/or the film transporting mechanism. When the hollow section is moved to an extended position in which it exposes the lens and the view finder, the two sections define a slot into which a careless user is likely to introduce a finger, an eyelash or an eyelid while holding the camera in front of his eye and while moving the two sections with respect to each other. The rear end of the slot is closed by a portion of a door which is pivotably mounted on the main section and can be opened to afford access to the film chamber. Alternatively, the slot can be overlapped by a panel which is rigid with the main section or with the hollow section of the housing.

Half-duplex modem for GSM radio telephone network

Abstract: The modem can receive digital data 12 and transform them into analog data 14 of the speech type capable of being processed by a GSM codec. The modulator part 1 includes a logic gates circuit 5, a battery of frequency generators 6-9, a multiplexer 10 and a variable-gain amplifier 11. The modem makes it possible to circumvent the IWF units of the GSM network.

Speech signal transmission

Abstract: In the transmission of speech in mobile telephone services where mobile handsets cooperate with a base station via a radio link, the base station being connected to a mobile switching center which, in turn, is connected to a public network, communication between the handsets and base stations is achieved using a standard selected to minimize bandwidth utilization. Sample standards are GSM and DECT. It has currently been proposed that in utilizing either of these standards a number of encoded speech channels will be multiplexed at the A interface between the base station and the MSC. The multiplex signal would then be converted to a 64 kb/s format at the interface between the MSC and the public network to which the MSC is connected. This proposal has a number of disadvantages. To alleviate these disadvantages it is proposed that conversion to the 64 kb/s format should be avoided if the recipient node can reconstitute the speech directly from its encoded format and that to such recipient nodes the encoded speech is sent in packetized form.

Security in mobile and cordless telecommunications

Abstract: Second generation mobile and cordless telephone systems, like GSM and DECT, provide for intersystem roaming and have integrated security features. These security features and the role played by smart cards in the implementation and management are discussed. The focus is on the security features provided in DECT because these are more comprehensive, and probably less widely known, then those provided in GSM. The method of authentication is identical to that used for authenticating subscribers accessing a GSM network. However, the DECT authentication mechanism includes an additional feature which is not provided within GSM. This feature provides for greater flexibility in the way authentication keys and authentication data may be managed. >

Digital radio receiver with decoding of confidence level information substituted for interleaved data

Abstract: A method of receiving digitized data encoded to permit forward error correction, for example convolutionally encoded data transmitted in a burst-mode radio communication system such as GSM. Prior to transmission a set of first data elements (bits) relating to a first message which may be associated with a first channel type (e.g. a traffic channel (TCH) in GSM) has selected bits substituted or stolen by data elements (bits) relating to a second message which may be associated with a second channel type (e.g. a fast associated channel (FACCH) in GSM). At the receiver the second message is recovered by extracting the substitute data elements. In order to improve bit error rate performance the received data is then modified by replacing the substitute data elements with low-or zero-valued "soft decisions", i.e. further data elements comprising respective components indicative of the low level of confidence associated therewith relative to the original data element. The modified data is decoded using, for example a Viterbi decoder (4) sensitive to the soft decisions to estimate the most likely set of data elements comprising the first message.

The Cellular Radio Handbook: A Reference for Cellular System Operation

Abstract: Preface to the Fourth Edition. About the Author. What is Cellular Radio? World System Standards--A History. Basic Radio. Planning--An Essential Network Function. Cell Site Selection and System Design. Radio Survey. Cellular Radio Interference. Cell Plans. Units and Concepts of Field Strength. Filters and Combiners. Cellular Repeaters. Antennas. Cellular Links. Base-Station Maintenance. Base-Station Control and Signaling. Power and Distribution. Protection and Grounding. Trunking. Switching. Traffic Engineering Concepts. Mobiles. Tower and Masts. Installations. Equipment Shelters. Budgets. Billing Systems. Marketing. Fraud. Data Over Cellular. Privacy. Rural and Offshore Applications of Cellular Radio. Interconnection. Preparing Invitations to Tender. Modulation/Demodulation Methods. Noise and Noise Performance. Digital Cellular. GSM Pan-European Cellular. DAMPS. NAMPS. E-TDMA. Code Division Multiple Access (CDMA). Japanese Digital. Satellite Mobile Systems. Cordless Telephone Technologies. iDEN. Wireless Local Loop. The Technology. Coding, Formats, and Error Correction. Digital Modulation. Other Mobile Products. Safety Issues. Buying Used Hardware. Appendix A: RF Propagation Routine Appendix B: ISO Model. Appendix C: Amplifier Classes. Appendix D: 911 Location Requirements. Appendix E: Distortion and Noise. Appendix F: Recommended Further Reading and Sources of Information. Appendix G: Internet Protocols. Appendix H: Erlang B and C Tables. Appendix I: Conversion of Units Used for Cellular RF. Appendix J: Country Codes. Glossary. Index.

BBTRX: A Baseband Transceiver Fora Zero If Gsm Hand Portable Station

Abstract: The BBTRX ( base band transmission and reception ) is a multi functional, CMOS, mixed analog/digitalVLSI circuit conceived to support the different ASIC's on the radio sub-assembly in the interfaces the zero IF 900 MHz RF quadrature modulator/demodulator chip and the base band GMSK modulator/demodulator circuits as well as the synthesizer and control unit. The BBTRX also controls the TX RF power amplifier output level and the burst shaping. The base band transceiver is a mixed analog digital design, developed in a 1.2 um analog cmos technology with a 38 mm2 die area. GSM handportable terminal. It

Implementation of PCNs using DCS 1800

Abstract: The digital cellular system (1800 MHz) (DCS 1800), a standard for personal communication networks (PCNs) that has been developed by the European Telecommunications Standards Institution (ETSI), is discussed. The GSM 900-MHz cellular standard, from which DCS 1800 is derived, is reviewed. GSM/DCS 1800 network interfaces and signaling, implementation of PCNs using DCS 1800, PCN cellular design, PCN transmission networks, and the services and functionality of DCS 1800 are described. >

Techniques for cellular networks incorporating microcells

Abstract: A layered radio cell architecture is described for high capacity cellular networks, such as PCN, in which the microcells are used to increase the capacity of the system. Alternative frequency assignment schemes which support this approach are considered. A technique for handling high speed mobiles is proposed. This scheme effectively prevents handover between layers for mobiles moving too fast for the microcells and is being incorporated into phase 2 of the GSM/DCS 1800 European digital cellular/PCN standards. >

TDMA burst-mode mobile radio communication system with forward error correction

Abstract: A method of receiving digitised data encoded to permit forward error correction, for example convolutionally encoded data transmitted in a burst-mode radio communications system such as GSM. Prior to transmission a set of first data elements (bits) relating to a first message which may be associated with a first channel type (e.g. a traffic channel (TCH) in GSM) has selected bits substituted or stolen by data elements (bits) relating to a second message which may be associated with a second channel type (e.g. a fast associated channel (FACCH) in GSM). At the receiver the second message is recovered by extracting the substitute data elements. In order to improve bit error rate performance the received data is then modified by replacing the substitute data elements with low-or zero-valued "soft decisions", i.e. further data elements comprising respective components indicative of the low level of confidence associated therewith relative to the original data element. The modified data is decoded using, for example a Viterbi decoder (4) sensitive to the soft decisions to estimate the most likely set of data elements comprising the first message.

KISS-16V2: a one-chip ASIC DSP solution for GSM

Abstract: Outlines the requirements for the various digital signal processing functions of the pan-European digital mobile cellular telephone system in terms of computational power and RAM and ROM capacities, and describes a digital signal processor (DSP) solution which is able to integrate all of these digital baseband functions for a hand-held terminal onto one VLSI chip. The KISS-16V2 processor, a low-power CMOS 16-b DSP, is optimized for digital telecommunications, especially for Groupe Speciale Mobile (GSM). A power-down mode together with the capability of memory and multiplier standby operation make this DSP well suited for handheld devices. A design strategy based on the extensive use of cell compilers and synthesis tools reduces the design of further DSP derivations to a minimum. >

A system framework for third generation mobiles

Abstract: A top-down process for the design, deployment, and evaluation of an example universal mobile telecommunications system (UMTS) is described. The process is based on iteration of system design detail and deployment strategies, revealing and providing focus on key system level tradeoffs. A top-down approach has proven to be an essential complement to bottom-up research in separate technical fields. As a preliminary conclusion, a UMTS design to meet the user requirements is technically feasible, and microcells should play a dominant role. Furthermore, the overall cost, and thus the economic feasibility of the system, will strongly depend on the cost of the microcell infrastructure. Minimizing this cost must therefore be of paramount importance for the third-generation mobile system. >

Communication request retry in cellular telecommunications networks and methods therefor

Abstract: A GSM cellular telephone system has cells (macrocells CI and CII). A GSM mobile station (MS) accesses the base station of the nearest cell in order to make communication with another party via a communications channel. During the setting up of such communication, the MS measures the signal strengths of adjacent cells. If there is no communication channel available in the initial cell, the network can thus set up communication via an unoccupied communications channel in one of the adjacent cells, provided the latter's signal strength is sufficiently high. The network is also capable of offering a more restricted service to subscribers to a microcellular system - for example, service in large cities or towns identified at X,Y and Z. A microcellular MS requests service via a microcell in one of these areas and the call is set up via that microcell if it has an available communications channel. The microcellular MS also measures the signal strength of adjacent cells. If there is no available communications channel in the initial microcell, the call is set up via an available communications channel in an adjacent microcell (if the latter's signal strength is great enough), but any attempt to set up the call via an adjacent cell which is not a microcell is blocked.

Developing technologies for personal communication networks

Abstract: The author reviews the technologies needed to meet the demands of the personal communication network (PCN) service, and gives the reasons why the three successful PCN applicants stated their preference for Groupe Speciale Mobile, (GSM) as the basis for PCN. Then the author discusses how, based on GSM, the DCS1800 standard (digital communication system at 1800 MHz) was elaborated by ETSI to meet PCN requirements. >

Performance evaluation of a hierarchical location registration and call routing for personal communications

Abstract: A new hierarchical location registration is presented for personal communications, and its related call routing through broadband-ISDN is described. The call routing utilizes signaling packets to directly access the lowest registration unit (HLRUO) of portable stations, so that centralized accesses as in GSM systems are avoided. After a description of the model of hierarchical location registration, the average number of registrations at each layer is statistically analyzed. The registration time interval vs. roaming range is derived. Thus, the average time interval for updating location information in the HLRUO is obtained. The performance evaluation of the proposed scheme and a comparison with GSM are outlined. >

A within-burst adaptive MLSE receiver for mobile TDMA cellular systems

Abstract: A simplified structure concerning the implementation of an adaptive digital receiver suitable for the pan-European cellular system Group Special Mobile (GSM) is described. In the GSM system, the performance of the received information is strongly affected by the multipath typical of the mobile communications channel. The proposed maximum-likelihood sequence estimation (MLSE) receiver based on the Viterbi algorithm compensates for selective distortion due to the multipath propagation and Doppler shift also in the case of fast channel variations using an adaptive tracking mode method. >

Key winning factors in deploying personal communications networks

Abstract: The goal to start up personal communications network (PCN) services requires low cost infrastructures as well as compact and low-priced pocket phones, because inexpensive and good quality personal communications services are the key attributes for success. It will be a challenge to infrastructure manufacturers and network operators to meet the massive market growth, technological advances, and quality of service. The paper focuses on the evolution of the GSM standard to support the PCN which will also be the main driving force for the third generation cellular system. Secondly, it highlights a few most important microcellular network planning techniques and requirements (especially in handovers). Finally, the infrastructure sharing solution for the PCN is discussed. >

Digital audio interface in a GSM device

Abstract: A GSM mobile telephone comprises a digital audio interface for interfacing the system simulator (SS) for testing purposes. In the arrangement according to the invention a digital signal processor (11) and a codec (12) are implemented in the same physical unit, whereby the system simulator (SS) interfaces to the telephone via a DAI block (14) and a JTAG data codec register (13) arranged in the DSP unit.

Assessment of GSM-link quality dependence on radio dispersion in rural environments

Abstract: The results of two separate measurement setups to investigate GSM-link quality dependence on radio dispersion in rural Faroese and Danish environments, a repetitive GSM-data burst sequence system, and a correlation sounder are presented. Both operated in the 900 MHz band. It is shown that the GSM system performance seems to be sensitive to Q16 both below and above the specified value of 9 dB, while the delay spread is of minor influence when Q16 is infinite. The burst error distribution seems quite unsensitive to interleaving for BER >

UMTS : mobile communications beyond the year 2000 : requirements, architecture and system options

Abstract: To support the massive demand for mobile services third generation land mobile systems will be based on a new architecture concept and adaptive techniques. Moreover, these systems are expected to offer service quality comparable to that of fixed networks contemporary to their deployment. UMTS (universal mobile telecommunication system) is the developing pan-European concept for third generation mobile systems. The paper briefly overviews the requirements for and the emerging architecture of the UMTS as they appear at the transition between two RACE research phases and the beginning of dedicated standardisation activity in ETSI.

Study of GSM system performance by a GSM network computer simulator

Abstract: A simulator (GSMSIM) of the digital cellular radiotelephone network, GSM, is described. The simulator is used as a tool for network design. The GSMSIM supplies: the load of the cells, the frequency and length of the calls in the cells, the number and place of the handovers and their reasons, and also power control parameters. The GSMSIM's ability to simulate the GSM radio telephone network gave the authors an excellent chance to study the system performance as functions of the base station system parameter sets. >

Arrangement for implementing a visitor location register in a cellular mobile telecommunications switching system

Abstract: This invention relates to apparatus and methods for providing cellular mobile telecommunication service in accordance with the requirements of the Global Systems for Mobile Communications (GSM) standard. A modular switching system is provided which performs the functions of the mobile switching center (210) plus those of a home location register (212), authentication center (216), visitor location register (214), and equipment identity register (218). The latter functions are advantageously spread among the modules of the switching system, thus avoiding the getting started cost of expensive dedicated data bases. A wireless global switching module advantageously switches mobile communications control messages among the modules of the system and between the modules and the base station systems (204), and terminates signaling links between the mobile switching center and the base station systems.