Showing papers on "GSM published in 1995"

Carrier frequency recovery in all-digital modems for burst-mode transmissions

Abstract: Reliable data detection in time division multiple access (TDMA) communication systems strictly depends on the availability of accurate estimates of the synchronization parameters of the received signal, ie, carrier frequency/phase and symbol timing, which must be derived from the burst preamble The authors focus on the carrier frequency estimation aspect, and present a fast, open-loop, all-digital frequency offset estimation technique, whose performance is assessed in two different communication scenarios: a TDMA satellite link employing standard modulation and burst formats, and a mobile cellular terrestrial radio system with signal and channel characteristics obeying the pan-European Group Special Mobile (GSM) recommendations The use of the algorithm as a frequency error detector (discriminator) in a recursive ("closed-loop") frequency offset estimator is also discussed, and some results concerning both the transient and the steady-state behavior of such a scheme are presented Finally, the impact of the algorithm on the receiver BER is briefly analyzed >

An introduction to GSM

Abstract: From the Publisher: Covering system architecture, implementation, and testing, this book provides you with an overview of GSM specifications and surveys competing cellular systems such as NADC and CDMA. Practical testing applications are explored in depth and compared with similar techniques used with analog cellular systems.

Flow control method for short message service-busy subscriber

Abstract: A flow control system and method in a global system for mobile communication (GSM) mobile telephone system for short message service (SMS). The SMS enables short text messages to be sent to and from mobile stations. The system and method is directed to a control for a service for messages sent to MSs (MT-SMs) and in particular to the case when several SCs send MT-SMs to the same mobile station subscriber. When several SCs send MT-SMs to the same subscriber, the first SC that establishes a short message dialog is allowed to be fully completed. While the short message dialog for this SC is established, any other SC attempting to send MT-SMs are detected and stored in a waiting list. After the initial short message dialog is completed, the same radio connection in maintained and each of the short messages corresponding to the SC addresses stored in the waiting list are sent by a first in-first to send principle. More generally, the system and method controls messages sent by SMS during a busy condition which enable a better utilization of the network and the network entity resources.

Wireless and Personal Communications Systems

Abstract: (NOTE: Each chapter contains an Introduction, Summary, Problems and References.) WIRELESS AND PERSONAL COMMUNICATIONS SYSTEMS. 1. An Overview of Wireless Technologies. Historical Background. Standards. Vision of PCS. 2. An Overview of Cellular Systems. Concept of Cellular Communications. First-Generation Cellular Systems. Technologies for Second-Generation Cellular Systems. Cordless Phones and Telepoint Systems. Second-Generation Cellular Systems. Second- Generation-Plus PCS Systems. Vision of the Third-Generation Systems. 3. Access Technologies. Narrowband Channelized Systems. Wideband Systems. Comparisons of FDMA, TDMA, and DS-CDMA. Capacity of a DS-CDMA System. Comparison of DS-CDMA and FDMA/TDMA System Capacity. 4. Fundamentals of Radio Communications. Radio-Wave Propagation. Multipath Characteristics of a Radio Wave. Capacity of a Communication Channel. Propagation Losses in Built-up Areas. 5. Fundamentals of Cellular Communications. Cellular System. Geometry of a Hexagonal Cell. Cochannel Interference Ratio. Cellular System Design in Worst-Case Scenario with an Omnidirectional Antenna. Cochannel Interference Reduction with the Use of Directional Antennas. Directional Antennas in Seven-Cell Reuse Pattern. Cell Splitting. Registration. Terminal Authentication. Handoff. 6. Digital Modulation Techniques. Baseband Signaling. Modulation Techniques. Demodulation Issues. 7. Antennas, Diversity, and Link Analysis. Objectives of a Cellular System Antenna. Antenna Gain. Free Space Path Loss. Receiver Noise. The Path Loss Over a Reflecting Surface. The Relationship between Directivity, Gain, and Beamwidth. Diversity Reception. Basic Combining Methods. Types of Diversity. Examples of Base Station and Mobile Antennas. 8. North American Cellular and PCS Systems. PCS Reference Models. 8.3 Services 8.4 Operation of a PCS System 8.5 Air Interface Unique Capabilities 8.6 Handoffs 9. European and Japanese Cellular Systems and North American PCS1900. GSM Public Land Mobile Network (PLMN). Objectives of a GSM PLMN. GSM PLMN Services. GSM Architecture. GSM Channel and Frame Structure. GSM Speech Processing. GSM Call Flow Scenarios. MSC Performance. North American PCS1900. Japanese Digital Cellular (JDC) System. 10. Security and Privacy in Wireless Systems. Security and Privacy Needs of a Wireless System. Methods and Procedures of Providing Privacy and Security in Wireless Systems. 11. Network Management for PCS and Cellular Systems. Goals for PCS Management. Management Requirements for PCS. OAM&P Standards for PCS and Cellular Network. Telecommunications Management Network. OSI Management. PCS Information Model. 12. Interworking in Wireless Systems. Speech Coding Interworking. Data Interworking. Signaling, Numbering, and Routing Interworking. Security and Authentication Interworking. Basic Services Interworking. Roaming between Similar Systems. Roaming between Dissimilar Systems. Emergency Calling Interworking. Billing Interworking. 13. Design of a Wireless System: A Case Study. Planning and Engineering a Cellular Radio System. Outline of the Engineering Procedure. Frequency Reuse and Channel Group Assignments. Considerations for a Start-Up System. The Process of Growing a Cellular System. Traffic Calculations for a Cellular and PCS System. 14. Cellular Digital Packet Data (CDPD) Network. CDPD Network Defined. The Network Architecture for CDPD. CDPD Protocols. CDPD Capabilities and Services. 15. Packet Radio Systems. Packet Radio Basics. The ARDIS Packet Radio Network. The RAM Mobile Data Packet Radio Network. Simple Packet Networks Using AX.25. The Network Operating System and TCP/IP. Appendix A. Channel Coding. Introduction. Hamming Code. BCH Codes. Reed-Solomon Codes. Appendix B. Orthogonal Functions. Appendix C. Traffic Tables. Appendix D. List of Abbreviations. Index.

UMTS: targets, system concept, and standardization in a global framework

Abstract: UMTS standardization responds to service and mobility requirements for telecommunications after the year 2000. UMTS provides a global and seamless coverage for high quality and user-friendly services ranging from paging or speech up to video or high bit rate data. With the service-oriented open-system concept, flexible radio access system and uncompromized security, UMTS will be the revolutionary step toward third-generation new radio services. The UMTS can be implemented as a radically new system, or when planned over time, as an evolution of existing GSM-based or ISDN-based network components. >

Co-channel interference cancelling receiver for TDMA mobile systems

Abstract: A method for co-channel interference cancellation in TDMA mobile systems exploiting the characteristics of mobile channels is proposed. The independently fading multipath channels provide a distinct waveform coding on each of the co-channel signals, which is a basis for signal separation in receivers. This enables the use of joint detection methods in receivers provided that accurate channel estimates can be obtained for all the cochannels. A joint detection and channel estimation algorithm for multiple co-channel signals are derived. The performance of the receiver is verified by simulations with the GSM system assuming that the strongest interferer is cancelled.

Untraceability in mobile networks

Abstract: User mobility is a feature that raises many new security-related issues and concerns. One of them is the disclosure of a mobile user’s reai identity during the authentication process, or other procedures specific to mobile networks. Such disclosure allows an unauthorized third-party to track the m.obile user’s movements and current whereabouts. Depending ou the context, access to auy information related to a mobile user’s location without his consent can be a serious violation of his privacy. This new issue might be seen as a conflicting requirement with respect to authentication: untraceability requires hiding the user’s identity while authentication requires the user’s identity to be revealed in order to be proved. What is needed is a single mechanism reconciling both authentication and privacy of a mobile user’s identification. The basic :solution to this problem is the use of uliases. Aliases insure untraceability by hiding the user’s real identity as well as his relationship with domain authorities. In this paper, we present a classification scheme to identify the various degrees of untraceability requirements. We then present an efficient method for the computation of aliases and apply It to a new set of inter-domain authentication protocols. We demonstrate that these protocols can be designed to meet various degrees of untraceability requirements. In designing these protocols, we try to avoid the drawbacks of authentication protoc:ols in existing mobile network architectures such as CDPD and GSM.

An advanced TDMA mobile access system for UMTS

Abstract: It is now clear that the most successful digital cellular system at present is the European developed TDMA (time division multiple access) based, Global System for Mobiles (GSM) and its DCS-1800 and DCS-1900 derivatives to service European PCN and American PCS concepts, respectively. The GSM system has been designed to evolve, with current standardization work within ETSI addressing a new derivative to service the needs of European railways along with other GSM phase 2+ extensions, such as General Packet Data Service, repeaters, and GSM/DCS roaming, which will keep GSM up to date through to the year 2000 and beyond. But how long can this evolution last? Is GSM the very best possible TDMA-based system? Can it evolve to provide the service needs of third generation mobile? What is the real potential of TDMA techniques? To answer some of these questions, an example TDMA-based radio access system has been developed within the European Advanced TDMA Mobile Access (ATDMA) project, with a specific focus on the terrestrial aspects of the third generation mobile system known in Europe as the Universal Mobile Telecommunication System (UMTS). In this article our baseline assumptions are first described and then a discussion on the transport and control requirements provide details of the ATDMA system concept in terms of the project's overall system model. >

Emerging mobile and personal communication systems

Abstract: The market demand for wireless communications has been demonstrated by the rapid growth of different second-generation wireless technologies that are optimized for particular applications and environments. Obvious examples include: digital cellular systems like GSM, ADC, PDC,and DCS1800 for widespread vehicular and pedestrian services, and cordless telecommunication systems based on CT2, DECT, and PHS standards for residential, business, and public cordless access applications. Efforts are also underway to consolidate the various radio environments and applications under a single standard for third generation wireless, i.e., FPLMTS. In the area of personal mobility, with the recent availability of "personal" numbers in various countries (e.g., 500 numbers in the United States), many fixed network operators are starting to offer such personal mobility services as "personal number service" and "number portability". These services represent initial stages of full personal mobility that will be provided by UPT in both wireline as well as wireless environments. The expected heavy demand for PCS in the United States and the underlying market/regulatory forces are driving the standardization and business activity. A number of air interface standards for the 1900 MHZ PCS band are being considered, which are based on TDMA, CDMA, and FDMA technologies singly or in combination. Many are variations of existing digital cellular and cordless telecommunications technologies. PCS networking standards are also being developed; both for standalone systems and for systems that will utilize public switched network capabilities. >

Interference diversity gain in frequency hopping GSM

Abstract: Wideband random frequency hopping is one of the key properties of GSM in an evolution towards PCS (personal communication services). Random frequency hopping introduces diversity on the transmission link, which improves the performance. In this paper, the impact of interference diversity in GSM is analyzed by means of bit level simulations of the GSM full rate speech channel. The analysis shows that the gain of interference diversity is highly system load dependent. The interference diversity gain is most striking in a system with low channel utilization. These results, together with system level simulations of frequency hopping GSM, show that random frequency hopping has implications for frequency planning. They indicate that GSM systems with simple frequency planning can be designed without sacrificing the overall system quality.

UMTS: fixed network issues and design options

Abstract: Discusses RACE 2066 MONET: the UMTS fixed network, general UMTS services and features, service provision model and service definitions, integrating fixed and mobile communication, UMTS architectures and signaling protocols. >

Signaling traffic volume generated by mobile and personal communications

Abstract: The authors develop a framework for evaluating the signaling load in a wireless network. Using bounds and approximations, we find that the key parameter to estimate is the number of location updates between two calls. The results are dependent upon the choice of protocols, but are independent of the traffic parameters relating user calling behavior and mobility. We use the framework to draw general conclusions about signaling load, as well as to compare the signaling loads for the European and North American systems and demonstrate the impact of architectural tradeoffs. We also describe the message flows for the major contributors to the signaling load that are defined in the GSM system. >

A 2.7 V GSM transceiver ICs with on-chip filtering

Abstract: A pair of low-power (2.7-6.6 V) ICs implements small GSM transceivers with a minimum of external components. Key aspects are the integration of the RF amplifiers, image rejection mixing, baseband channel selectivity filters and peripheral functions on-chip. 1.5 nF/mm/sup 2/ capacitors and both bipolar and CMOS devices are used in the 13 GHz f/sub T/ process to mix analog and digital functions. A single superhet architecture is used for both transmitter and receiver, one IC containing the RF and the other the IF circuitry. Both circuits and the common synthesizer and VCOs are time-multiplexed between transmit and receive. (GSM is a TDMA system.) An IF such as 400 MHz is envisaged for both transmit and receive to ease the filtering of spurious mixing products and allow applications in the 2 GHz band.

The design of location areas in a GSM-network

Abstract: The operator of a cellular radio network of the GSM-standard has to group the cells of the network to location areas. When a mobile station in idle mode changes from one cell to the other the mobile station informs the network of its change only if the new cell belongs to a different location area. When an incoming call arrives, a paging message needs only be sent in those cells belonging to the location area where the mobile station has last performed location updating. The operator has to balance the amount of paging messages with the amount of location updatings. We present an algorithm for the design of location areas which has been developed for the German GSM-network D1 operated by the DeTeMobil.

Cytogenetic Effects of Microwaves from Mobile Communication Frequencies (954 Mhz)

Abstract: Whole blood samples were exposed to a 954 MHz emitting antenna from a GSM (Global System for Mobile Communication) base station and cultivated for analysis of chromosome aberrations. A limited number of blood samples from maintenance workers being professionally exposed to microwaves of this and other frequencies was also investigated. Although some cytogenetic damage was obtained in vitro when blood samples were very close to the antenna, we may, according to our results, consider that microwaves emitted by a GSM base station are not able to induce defects in the general population.

A traffic supervision system for vehicles

Abstract: To protect and watch transport units consisting of a towing unit and one or more transported or transporting units, the towing unit has a data processing system (1) capable of communicating with the outside world via communications and GPS satellites (45) and/or a GSM system (39) and with tags (10B) burried in a road. The transporting or transported unit or units additionally have a data processing system (15) capable of communicating with a data processing system (1) in the towing unit via a wireless interface (7) or interface (8). The data processing system in the transporting or transported unit or units is moreover interfaced with an aerial (16) capable of communicating with tags in a road or surfaces (10B) or tags (10A) located in the top of transporting or transported units. A system designed as described above provides the advantage that a cargo or a transport unit can always be positioned and watched.

A Network Emulator to Support the Development of Adaptive Applications

Abstract: Mobile applications must operate in environments in which the network connectivity, input/output devices, power and contextual information available to them may all vary. Applications which react to changes in these parameters in order to ensure continuing service to the user are termed adaptive applications and have recently emerged as an area of intense research activity. In this paper we describe the design and implementation of a network emulator which facilitates research in this field by allowing applications to be exposed to user controlled fluctuations in network service. The emulator can be used with any application which uses UDP and requires only minimal changes to the application or, it may be used with applications written using the ANSAware distributed systems platform in which case no changes are necessary to the application. The design and implementation of the emulator are described in this paper as our experiences of using the emulator to model three distinct types of wireless network: GSM, an analogue cellular service and a simple shared radio channel. The source code for the emulator is freely available and instructions on obtaining the code are also included.

Mobile station locating in GSM

Abstract: The positioning of a mobile station (MS) will become mandatory in the US to support wireless emergency calls in the near future. Also, lots of other applications are foreseen for the location service, when implemented. In this paper the authors study the feasibility of the Global System for Mobile Communications (GSM) and MS location. The TDMA based GSM system offers some inherent means of calculating the location of the MS. In the MS there is already implemented a set of measurement functions that can be used to locate the MS. We investigate the use of timing advance (TA) and observed timing difference (OTD).

The GSM procedures in an integrated cellular/satellite system

Abstract: In an integrated cellular/satellite system for mobile communications a satellite subsystem cooperates with a terrestrial cellular network for providing user services. The paper addresses the problems related of the reuse of the procedures of the GSM cellular standard in an integrated system. Allowing at most changes only at the mobile terminal and/or in the satellite network. The results of the study show that most of the GSM procedures can be reused in an integrated system (in a few cases with limited protocol variations) but some others would require modifications to the cellular network. The results of this study shall also be useful for the suitable definition of the protocols of an integrated satellite/terrestrial system for the next generation of mobile and personal communication services. >

Mobile speed sensitive handover in a mixed cell environment

Abstract: As mobile cellular radio systems evolve into personal communications, a mixed cell architecture is introduced to successfully meet the increasing user capacity requirements and to preserve the system integrity. Cells of different sizes co-exist in a two-layer structure comprising: micro cells on the lower layer and macro (umbrella) cells on the upper layer. This paper reports on a mobile speed sensitive handover criterion, which allows sufficient differentiation between slow and fast-moving mobiles in a mixed cell environment. Based upon this criterion, handovers from umbrella into micro cells can be avoided for fast moving mobiles. Correspondingly, slow-moving subscribers are "dropped" from the umbrella into an underlaid micro cell and remain served by the micro-cell-layer, while those who tend to increase their speed over a given threshold are "steered" towards the umbrella-cell-layer. The new technique is compared with a standard handover strategy by means of emulations on measured propagation data in different deployment scenarios. The results indicate that utilizing the mobile speed sensitive handover in a mixed cell environment, the system performance can be significantly improved with respect to both handover load in the fixed network and forced call terminations.

Radio communication device capable of communication in a plurality of communication systems

Abstract: A radio communication device which is capable of effecting communications in different communication systems and is highly advantageous economically has a main communication unit capable of effecting communications in a first digital cellular communication system (GSM), and an additional unit to be attached to said main communication unit for effecting communications in a second digital cellular communication system (PCN) which differs from said first digital cellular communication system. The main communication unit includes variable-bandwidth filters compatible with both GSM and PCN. The additional unit comprises a power amplifier, and the main communication unit has a power amplifier. Switching can be made between these power amplifiers to make the radio transmission device compatible with both GSM and PCN. The radio communication device has many components shared by GSM and PCN and hence is highly economical.

Analysis of CDMA range extension due to soft handoff

Abstract: We provide an analysis of CDMA range extension due to soft handoff. A simulation of GSM hard handoff and CDMA soft handoff is presented. In these simulations, a collection of 90 second calls are tracked through the system and the margin required to meet a constant call reliability is determined. A comparison of these margins for both GSM and CDMA indicate that, under a variety of conditions, the shadow fade margin required by the GSM system is about 2.6-3.6 dB higher than that needed by the CDMA soft handoff.

Mobile communication system and method therefore

Abstract: The invention concerns a mobile communication system where a manufacturer of mobile equipment (ME) has implemented in the equipment additional features exceeding the system standards and at least some of those additional features are supported by an operator's network (ON). The mobile equipment have an equipment identity code (IMEI) uniquely identifying the equipment, and the operator's network (ON) can request that identity code. In a system according to the invention the operator's network (ON) contains, primarily in the reqister equipment (NR) of the network, the means (LT) for connecting the information (AFS) about the additional features of a mobile equipment with the equipment identity code (IMEI) requested from the equipment (ME). In addition, the network contains, in the exchange (MSC), for example, the means (FSC) for determining on the basis of the received information (AFS) which of the additional features the network supports. The resulting information (SFS) is signalled to the mobile equipment (ME) that has the means (FC, MC) to enable the additional features according to the information (SFS). Connecting the additional feature set information (AFS) with an equipment identity code (IMEI) can be implemented with a look-up table, for example, and in the European GSM system the look-up table may comprise the list of approved equipment supplemented with the additional feature set information in the equipment identity register of the network.

Proposed operation of GSM packet radio networks

Abstract: The standardization of the GSM General Packet Radio Service (GPRS) is progressing in European Telecommunications Standards Institute (ETSI). This paper describes the proposed architecture, signaling and protocols for the GPRS network. Also, the network layer interworking, mobility management, service establishment/management, as well as link layer issues are discussed here.

GSM-R: global system for mobile radio communications for railways

Abstract: The paper describes general requirements of European railways for a common universal mobile radio system. The reasons for selecting the Global System for Mobile Communications (GSM) as a basis are discussed, as well as necessary extensions to this standard to meet the railway requirements. The resulting GSM-R system offers new services comparable to those of Private Mobile Radio (PMR).

Application of GSM in high speed trains: measurements and simulations

Abstract: The paper presents results of measurements and simulations concerning the application of the European GSM system in high speed trains travelling at up to 500 km/h. The aim is to answer the question to what extent GSM (performance specified up to 250 km/h) can cope with the high velocities which are demanded for future railways. Measurements along railway lines have shown that a railway mobile radio channel results in better performance (Rice channel) than standard mobile radio channels (Rayleigh or weak Rice channel, see GSM-Recs). BER and block error rate of GSM traffic channels up to 500 km/h are simulated. Comparison of the results at 250 km/h and 500 km/h shows that the GSM high velocity problem can be solved either by increasing the SNR by about 2 dB or by increasing the Rice parameter c by about 6 dB (numerical values for profile RA=rural area; railway channel with c=6 dB against standard channel with c=0 dB), i.e. the BER at 500 km/h (railway channel) is not worse than the BER at 250 km/h (standard channel). A simple example shows that the benefit in the transmission of telegrams consisting of blocks of decoded bits can be much higher, The desired channel performance, i.e. a strong direct path (high Rice parameter), can be achieved by careful radio coverage planning along the railway line. This means a GSM standard receiver is sufficient to cope with the GSM high velocity problem and no additional means are needed. (7 pages)

Subscriber identity authentication in fixed cellular terminals

Abstract: The fixed cellular terminals (TCF) include a subscriber identity module which, in order to permit authentication of the identity of the subscriber (U) without any intervention on his part, is fixed. It is of particular application in fixed cellular terminals (TCF) of the GSM type that form part of an access network based on the infrastructure of a cellular mobile network. These subscriber identity modules incorporate the function of subscriber identification number verification. During the installation stage each fixed cellular terminal (TCF) stores the subscriber identification number, which it later provides to the subscriber identity module making it become fully active when the number supplied coincides with that held in the subscriber identity module. In the initialisation process, the fixed cellular terminal (TCF) generates a new subscriber identification number, that it stores internally in its subscriber identity module for use in subsequent reinitialisations.

Performance and characteristics of GSM-based PCS

Abstract: Personal communication services (PCS) based on the GSM system, also called PCS1900, provides an advanced wireless system concept with a high performance air interface. The combination of techniques such as frequency hopping, equalization, channel coding and spatial diversity help in controlling the hostile radio environment. The performance is evaluated mainly in terms of coverage and capacity, and compared with PCS based on IS-95 CDMA. The results show a coverage advantage for GSM-based PCS (PCS1900) corresponding to fewer required base stations than for IS-95 CDMA. The reason is the large frequency diversity that is possible with PCS1900. The capacity in terms of channels/sector is comparable for the two systems. When using the same speech coder rate, PCS1900 will have a small capacity advantage. The concept using hierarchical cell structures for achieving a high system capacity per km/sup 2/ in a flexible way, is only supported by PCS1900.

Network functions and signalling for personal roaming between digital cellular standards

Abstract: A possible short-term solution for creating an inter-cellular standard roaming service is presented. An inter-cellular standard roaming service is, for example, the service whereby a GSM mobile subscriber can roam into a PDC network operator by means of a user identity module. For interconnecting the different cellular systems, two network nodes called "interworking location register (ILR)" and "interworking mobile services switching center (IMSC)" are proposed. These network nodes are designed to cause no modifications in the original cellular system. With this in mind, the network architecture of the digital cellular standards is considered. Furthermore, the outline of the basic call procedures for the roaming subscribers based on the proposed network architecture model is described.

Frequency agile transceiver with multiple frequency synthesizers per transceiver

Abstract: A base station communicates with a plurality of mobile stations over a cellular network. In one embodiment, the base station includes a receiver having a receiver synthesizer input, where the receiver is configured to receive inbound information from the mobile station on a first predetermined frequency. The receiver further has two programmable frequency sources that are configured to alternately supply a receiver synthesizer input signal to the receiver. The base station also includes a transmitter having a transmitter synthesizer input, where the transmitter is configured to transmit outbound information to the mobile station on a second predetermined frequency. The transmitter further has two programmable frequency sources that are configured to alternately supply a transmitter synthesizer input signal to the transmitter. A processor is connected to the receiver and the transmitter and is configured to decode the inbound information and to encode the outbound information to communicate with the mobile station. This two-way communication continues by programming and then alternately selecting the receive synthesizers to receive on the correct frequency, and by programming and then alternately selecting the transmit synthesizers to transmit on the correct frequency. A preferred protocol is Global Systems for Mobile Communication (GSM).