Showing papers on "GSM published in 2002"

Monitoring of call information in a wireless location system

Abstract: In an overlay Wireless Location System, an Abis interface is monitored to obtain information used to locate GSM phones (S116). Signaling links of the Abis interface are passively monitored to obtain certain information, such as control and traffic channel assignment, called number, and mobile identification, which is not available from the GSM air interface of the reverse channel (S110-S116). This approach also applies to IDEN and can be broadened to include CDMA systems where the GSM architecture has been used and the system includes a separated BTS to BSC interface.

Private cellular network with a public network interface and a wireless local area network extension

Abstract: A communication system ( 100 ) and method for coupling a wireless local area network (WLAN 128 ) to a public network ( 102 ) to enable communication between User Equipment terminals (UEs 130 ) associated with the WLAN and the public network. The public network ( 102 ) can include a GSM ( 110 ) and/or a 3G-network ( 114 ). The WLAN ( 128 ) can include a HiperLAN, HiperMAN, or 802.11 network. Preferably, the communication is voice communication, and the system ( 100 ) is configured to enable the UEs ( 130 ) to access supplementary services provided by the public network ( 102 ). Subscriber and security information for the UEs ( 102 ) can be provided to the public network ( 102 ) from a SIM ( 134 ) associated with each UE, or from an identity module ( 138 ) comprising either a private memory with information stored therein, or a card holder/reader holding cards with subscriber and security information for one or more UEs. Optionally, the system ( 100 ) further includes a private cellular network ( 122 ) the WLAN ( 128 ) also enables communication between the UEs ( 130 ) and the private cellular network.

GSM, GPRS and EDGE Performance: Evolution Toward 3G/UMTS

Abstract: From the Publisher: GERAN (GSM EDGE Radio Access Network) is an enhanced version of EDGE (Enhanced Data Rates for Global Evolution) that is a vital step along the way to full 3G servicesExplains the key parts of both ETSI GSM and 3GPP/GERAN standards Introduces 3GPP ALL IP architecture for future GSMC (Global System for Mobile Communication) Examines the coverage and capacity of GSM/EDGE and AMR (Adaptive Multi Rate) Introduces a totally new approach for Radio Access Network automated optimization Discusses positioning of GERAN and UTRAN (UMTS Terrestrial Radio Access Network)

Idle mode handling in a hybrid GSM/CDMA network

Abstract: In a mobile wireless telecommunications system, which includes base stations (30) of a first type operating over a first air interface, and base stations (32) of a second type operating over a second air interface, a method for reselection by a mobile station (40) camped on a cell associated with a first base station (30), which is of the first type, of a second base station (32), which is of the second type. The method includes receiving signals over the second air interface from the second base station (32) and evaluating a characteristic of the signals. Responsive to the characteristic, the second base station (32) is selected in place of the first base station (30), and the mobile station (40) camps on a cell associated with the second base station (32).

A single-chip quad-band (850/900/1800/1900 MHz) direct conversion GSM/GPRS RF transceiver with integrated VCOs and fractional-n synthesizer

Abstract: Recent trends in the integration of entire systems on-chip have spurred the development of homodyne radios as alternatives to the more mature yet harder to integrate superheterodyne architectures. This paper presents a monolithic device that integrates all of the functions necessary to implement a multiband homodyne global system for mobile telecommunications (GSM) radio except for the power amplifier (PA) and radio frequency (RF) passives. The single BiCMOS chip includes a quad-band direct conversion receiver that down converts RF to quadrature analog baseband. The front-end circuitry is followed by a low-DC-offset, high-dynamic-range, analog I/Q baseband chain. The transmit section is comprised of a quad-band up-conversion transmit phase-locked loop (PLL) including on chip transmit voltage-controlled oscillators (VCOs). The stringent GSM receive band phase noise specifications are met without the use of surface acoustic wave filters. A single /spl Sigma//spl Delta/ fractional-N synthesizer locking a fully integrated ultrahigh frequency VCO generates the system local oscillator signal.

The Challenge of Mobile Devices for Human Computer Interaction

Abstract: Current mobile computing devices such as palmtop computers, personal digital assistants (PDAs) and mobile phones, and future devices such as Bluetooth and GSM enabled cameras, and music players have many implications for the design of the user interface. These devices share a common problem: attempting to give users access to powerful computing services and resources through small interfaces, which typically have tiny visual displays, poor audio interaction facilities and limited input techniques. They also introduce new challenges such as designing for intermittent and expensive network access, and design for position awareness and context sensitivity. No longer can designers base computing designs around the traditional model of a single user working with a personal computer at his/her workplace. In addition to mobility and size requirements, mobile devices will also typically be used by a larger population spread than traditional PCs and without any training or support networks, whether formal or informal. Furthermore, unlike early computers which had many users per computer, and PCs with usually one computer per user, a single user is likely to own many mobiles devices [1] which they interact with indifferent ways and for different tasks.

Public safety access point (PSAP) selection for E911 wireless callers in a GSM type system

Abstract: Public safety access points are selected in a wireless network for E911 calls based on ESRD substitution when ESRKs are not being used. The present invention was conceived as an ESRK workaround solution to implement Phase II of the E911 rules from the starting point of a Phase I implementation. ESRKs, ESRDs or ESRVs are initially obtained and managed for each PSAP in a particular carrier's area. Then, Phase I processes are modified to wait to see if Phase II GSM location information will be reported in a timely manner (e.g., within a second or two or so) before committing to a default selection of a particular PSAP based on information available (e.g., based on the location of a serving cell site).

Method and device for authenticated access to a station on local data networks in particular radio data networks

Abstract: The invention relates to methods, devices and systems for the authenticated access to a data network by means of a station (WH) compatible with a data network (WLAN), which permit an authentication of the station and user. A device, for example a mobile radio device, is used for the above, which is authenticated in another system. In addition to the authentication, in particular a charging of services in a data network or another communication system (GSM) which is accessible by means of the data network is thus possible.

EDGE: Enhanced Data Rates for GSM and TDMA/136 Evolution

Abstract: This chapter contains sections titled: Introduction Background Physical Layer Link Layer EGPRS Performance Conclusions This chapter contains sections titled: References

Partitioning attacks: or how to rapidly clone some GSM cards

Abstract: In this paper, we introduce a new class of side-channel attacks called partitioning attacks. We have successfully launched a version of the attack on several implementations of COMP128, the popular GSM authentication algorithm that has been deployed by different service providers in several types of SIM cards, to retrieve the 128 bit key using as few as 8 chosen plaintexts. We show how partitioning attacks can be used effectively to attack implementations that have been equipped with ad hoc and inadequate countermeasures against side-channel attacks. Such ad hoc countermeasures are systemic in implementations of cryptographic algorithms, such as COMP128, which require the use of large tables since there has been a mistaken belief that sound countermeasures require more resources than are available. To address this problem, we describe a new resource-efficient countermeasure for protecting table lookups in cryptographic implementations and justify its correctness rigorously.

Method and System for Transparently and Securely Interconnecting a WLAN Radio Access Network Into a GPRS/GSM Core Network

Abstract: A method and system are provided for integrating a WLAN radio access network into a GSM/GPRS core network wherein gateways are added that transparently transport services between the two networks. A further aspect of the invention is secure authentication. The system has two network elements: a Radio Link Manager (RLM) and a Radio Access Controller (RAC), and a software application, a Multi-Link Client (MLC) to control the functionality of the integration and the authentication. The MLC resides on a user device. The RAC provides protocol stacks and interworking functions to allow the MLC to talk to a Home Location Register (HLR). The RLM and MLC set up a “tunnel” employing, for example, PPP over Ethernet (PPPOE), and all of the data packets received on this tunnel are forwarded by the RLM to the Gateway GPRS Support Node (GGSN over a further tunnel using the GPRS Tunneling Protocol (GTP).

DART: a dynamically reconfigurable architecture dealing with future mobile telecommunications constr

Abstract: In addition to the high performance requirements inherent to multimedia processings or to W-CDMA, future generation mobile telecommunications brings new constraints to the semiconductor design world. In fact, to support these processings, a system will have to be very flexible, in order to support the various algorithms allowed by the norm and the addition of new services, while keeping an energy consumption level compatible with the portability notion of this system. In order to associate high performances and low energy consumption in a flexible system, we developed a dynamically reconfigurable architecture called DART. The aim of this paper is to present this architecture and to estimate its level of performance and its adequacy with future generation mobile telecommunication systems.

Reducing location update and paging costs in a PCS network

Abstract: Mobility tracking operations in a personal communication service (PCS) system are signaling consuming. Several strategies have been proposed in the literature to reduce both the location update (LU) and the paging (PG) costs. In this paper, we propose a location-tracking algorithm called three-location area (TrLA), combined with selective paging. In TrLA, the mobile terminal (MT) allocates the identification of three neighboring location areas (LAs) in its local memory. We call this set of three LAs, a big-location area (BLA). Each time the MT exits the BLA, it triggers an LU message to the system databases via a base station, in order to maintain the databases up to date. The MT also updates its cache memory. A two-step selective PG is also considered and compared with the single-step (or nonselective PG). An analytical model based on a semi-Markov process has been used to evaluate our proposal. This scheme is compared with the classical Global System for Mobile Communications (GSM) standard and the two-location algorithm proposal. As a result, this new scheme outperforms the cited strategies, and in our opinion, it can easily be implemented in existing standard cellular and personal communication systems.

Inter-rat cell reselection in a wireless communication network

Abstract: This disclosure is directed to a technique for efficient inter-RAT (Radio Access Technology) cell reselection in a wireless communication system. In general, following an unsuccessful cell reselection attempt, the technique involves upgrading one or more cell selection criteria for the pertinent cell. By upgrading the cell reselection criteria, requirements for reselection of the cell in the future are made more stringent. The technique may promote more efficient cell reselection performance, thereby reducing the frequency of repeated, unsuccessful reselection attempts for the same cell. In this manner, the technique can be effective in reducing power consumption and computational overhead incurred by unsuccessful cell reselection attempts, thereby increasing standby time in a wireless communication device. The technique may be implemented within a wireless communication device that supports two or more RAT types, such as WCDMA and GSM. Accordingly, in some cases, the technique may be implemented within a GSM/WCDMA UE.

Method and system for GSM billing during WLAN roaming

Abstract: The invention relates to a method and system for recording and billing services during the roaming of a mobile IP node (20) in heterogeneous WLANs. According to the invention, first call detail records are transmitted from an access server (23/1001) to a billing module (1003) and second call detail records are transmitted from the access server to a proxy module (1002). The service requested from a provider (1008) of a fixed network (1007) is billed (1016) by means of a clearing module (1004) and/or the TAP files (1017) are transmitted to a GSM (1005) service provider (1006) for billing.

Mobile Radio Networks: Networking, Protocols and Traffic Performance

Abstract: Preface Preface to the Second Edition Introduction System Aspects GSM System Enhanced GSM Services Other Public Mobile Radio Systems Third GenerationCellular: UMTS Trunked Mobile Radio for Group Communications Paging Systems Cordless Telephone Systems DECT Wireless Local Loop Systems Personal Handyphone System (PHS) Wireless Broadband Systems and Wireless ATM Wireless Local Area Networks Self--0rganizing WLANs with QoS Guarantee Mobile Satellite Communications UPT ---- Universal Personal Telecommunication Next Generation Systems Appendix A: Queuing and Loss Systems Appendix B: Standards and Recommendations Appendix C: International Frequency Allocations Appendix D: The Frequencies of European Mobile Radio Systems Appendix E: The GSM Standard Appendix F: The UMTS Standard Appendix G: Acronyms Index

Interworking and interoperability of GPRS systems with systems of other technology families

Abstract: A GPRS interworking and interoperability function (IIF) is interposed between a serving GSM/GPRS wireless system and a second wireless system of a different technology family to allow a mobile station homed to the second wireless system to operate in the GSM/GPRS system. The IIF executes or emulates the behavior of a GPRS HLR when communicating with the GSM/GPRS system, and executes or emulates the behavior of an MSC/VLR of the home system technology family when communicating with the home system. When a mobile station registers in the serving system, the MSC/VLR portion of the IIF transmits a registration notification message to the home system HLR specifying the address of an associated SGSN as though it were an MSC.

A real-time DOA-based smart antenna processor

Abstract: We designed, built, and tested a real-time processor for a direction-of-arrival-based smart antenna GSM 1800 base station with eight half-wavelength spaced antenna elements. Its processing steps include direction-of-arrival (DOA) estimation, user identification, tracking, beamforming, and signal reconstruction. We demonstrate that the accuracy of DOA estimation is not of primary concern, but the robustness is. This can be assessed by a new parameter, the estimation range. Tracking of reliable user DOAs only, increases the robustness against interference. Our tracking concept is compatible with frequency hopping. We quantify the benefits of smart antennas by the statistics of the gain in carrier-to-interference ratio (C/I) and in signal-to-noise ratio (SNR), both measured at the 90 or 99% levels with actual transmitted data. In an urban environment with large angular spread and overlap of user and interferer signals, the C/I gain is as high as 18 dB. Interferer nulling increases the C/I gain only slightly, but enhances robustness against angular spread, particularly if broad nulls are applied. Separating SNR gain in its contributions due to beamforming and diversity gives valuable insight into the way of operation. In uplink, the processor can exploit angular diversity. The entire suite of processing steps is done within less than 1 ms, demonstrating that sophisticated DOA-based smart antenna processing is feasible in real time. Our solution does not require any change in the GSM standard.

General Packet Radio Service [GPRS]

Abstract: Discusses the evolution from GSM to GPRS communications. The network architecture, protocol stack, and mobility management are discussed.

Dual-mode RF communication device

Abstract: A novel RF to IF converter operates in two modes allowing both wide bandwidth signals and narrow bandwidth signals to be processed using the same wide bandwidth bandpass filter as well as a dual-mode image-reject mixer As a mobile receiver, both wide bandwidth WCDMA or IMT-2000 signals and narrow bandwidth GSM signals pass through the same wide bandwidth channel select filter In the GSM mode, signals lying to one side of the frequency range of the narrow GSM signal are attenuated by the wide bandwidth channel select filter Then signals lying to the other side of the GSM signal are attenuated by an image-reject mixer The image-reject mixer also downconverts the GSM signal In the WCDMA or IMT-2000 mode, the wide bandwidth channel select filter attenuates signals outside of the WCDMA or IMT-2000 channel bandwidth, and the image-reject mixer downconverts the wide bandwidth signal without rejecting signals

China's perspectives on 3G mobile commuunications and beyond: TD-SCDMA technology

Abstract: China, as the largest developing country in the world, has been emerging as a nation with the fastest penetration rate growth in mobile communications, exceeding the United States to become the largest single mobile cellular market in terms of subscriber population. The recent successful admission to the World Trade Organization (WTO) has given China new momentum for further development of its mobile communications infrastructure and fueled international competition as well in the mobile communication market of the country. Since the opening up of its economy, China has spent billions of dollars to purchase equipment from foreign telecommunication manufacturers, which has created a heavy burden to modernize its legacy industrial sectors. This is the situation China is eager to change. The TD-SCDMA standard was proposed by the CWTS of China to ITU in 1998 as an effort to bring China on a par with other developed countries in mobile communications system development and also to make the country less dependent on foreign vendors. The proposal was approved by ITU as one of the candidate standards for 3G mobile communications in May 2000 and accepted by 3GPP in March 2001. The TD-SCDMA standard makes use of TDD synchronous CDMA technology and offers several operational advantages. For instance, it allows the existing GSM core networks to be upgraded to the TD-SCDMA platform along a relatively easy path. Therefore, it can be very attractive to service providers in regions where worldwide popular GSM system is in operation. The TD-SCDMA standard has received the full blessing of the Chinese government and will surely play a critical role in mobile communications development in China as well as in the world; its impact should never be underestimated. In this survey article the historical background as well as the technical content of the TD-SCDMA standard will be addressed.

Performance issues with general packet radio service

Abstract: The General Packet Radio Service (GPRS) is being deployed by GSM network operators world-wide, and promises to provide users with “always-on” data access at bandwidths comparable to that of conventional fixed-wire telephone modems. However, many users have found the reality to be rather different, experiencing very disappointing performance when, for example, browsing the web over GPRS. In this paper, we examine the causes, and show how unfortunate interactions between the GPRS link characteristics and TCP/IP protocols lead to poor performance. A performance characterization of the GPRS link-layer is presented, determined through extensive measurements taken over production networks. We present measurements of packet loss rates, bandwidth availability, link stability, and roundtrip time. The effect these characteristics have on TCP behavior are examined, demonstrating how they can result in poor link utilization, excessive packet queueing, and slow recovery from packet losses. Further, we show that the HTTP protocol can compound these issues, leading to dire WWW performance. We go on to show how the use of a transparent proxy interposed near the wired-wireless border can be used to alleviate many of these performance issues without requiring changes to either client or server end systems.

Cellular access control and charging for mobile operator wireless local area networks

Abstract: This article presents a system architecture, design considerations, and rationale for a mobile operator wireless LAN. The article also discusses the system implementation and performance issues. The system presented reuses GSM and GPRS mechanisms for user authentication, access control, subscriber management, operator roaming, and billing, while still being compatible with wireless Internet service provider networks and IETF and IEEE protocols such as RADIUS, EAP, and IEEE 802.1x. The architecture is a result of research carried out by Nokia between 1999 and 2002. The designed architecture has also been verified in a complete system implementation.

Multiple Access Protocols for Mobile Communications: GPRS, UMTS and Beyond

Abstract: From the Publisher: A comprehensive discussion of multiple access protocols for cellular systems and the consideration of the specific constraints and capabilities of second and third generation systems regarding the multiple access protocols. Beginning by introducing the cellular concept and discussing second and third generation cellular communication systems, including the evolution from these systems to IP-based systems, the authors then identify the requirements for and problems related to multiple access. In accordance with ETSI and 3GPP standards, a split is made into basic multiple access schemes such as CDMA, TDMA and FDMA and multiple access protocols. The pros and cons of CDMA and TDMA for third generation systems are discussed as well as medium access in GSM, GPRS and UMTS, essentially based on R-ALOHA protocols in all these systems. Data access delay and voice dropping performance is assessed and the different UTRA modes are considered. Provides an accessible text for individuals with little prior knowledge of cellular communication systems or multiple access protocols Provides an overview of existing material on cellular communications, multiple access protocols and a combination of the two Presents extensive research carried out by the authors including extended packet reservation multiple access protocols such as TDMA and CDMA, protocol enhancements and modelling of the physical layer A valuable reference resource for researchers and engineers in the field of cellular communications and packet-based communications, as well as postgraduate and research students in this rapidly evolving field.

Method and system for inter-operator handover between WCDMA and GSM

Abstract: A method and system for inter-operator handover in a telecommunications network comprising a greenfield WCDMA operator and a GSM/WCDMA operator. When a mobile terminal of the greenfield operator is moving from the coverage area of the home network to the GSM/WCDMA area, a neighbor list of GSM cells is provided to the mobile terminal (116) for handover to a GSM cell when the home network coverage is not available. When the mobile terminal is returning home from the GSM/WCDMA area, a neighbor list of the home cells is provided to the mobile terminal (120) so that the greenfield mobile station is connected to its home network whenever there is coverage. Preferably, the neighbor lists are provided to the mobile terminal only in the connected mode.

A 5-mW sigma-delta modulator with 84-dB dynamic range for GSM/EDGE

Abstract: A sigma-delta modulator designed as part of a complete GSM/EDGE (enhanced data rate for GSM evolution) transceiver is described. High-resolution wide-band analog-to-digital converters enable the receiver to rely on digital processing, rather than analog filtering, to extract the desired signal from blocking channels. High linearity and low power consumption are the most stringent requirements for the converters in this wireless application. A single-bit 2-2-cascaded modulator operating at 13 MHz has been adopted for high linearity and stability. Low-power low-voltage techniques have been applied along with a top-down design approach in order to minimize the power dissipation. The /spl Sigma//spl Delta/ modulator achieves 13.5 bits of resolution over a bandwidth of 180 kHz while dissipating 5 mW from 1.8-V and 2.4-V supplies. The circuit has been implemented in the CMOS portion of a 0.4-/spl mu/m (drawn) BiCMOS technology and occupies an active area of 0.4 mm/sup 2/.

Performance analysis of GSM networks with intelligent underlay-overlay

Abstract: The paper presents an analytical model for a GSM-based cellular mobile network that applies an intelligent under-overlay (IUO) scheme to increase capacity by increasing frequency reuse while maintaining service quality. The IUO is a multi-layer cell structure that is based on dividing the frequency band into super layer and regular layer frequency groups. The super frequencies (channels) can be used by mobile stations with good C/I (carrier/interferer) ratio, while the regular frequencies can be used over the whole cell. The use of IUO is expected to provide up to 40% gain of capacity (see Nokia Telecommunications, www.nokia.com). We study the effect of various parameters on the performance of networks using IUO and provide practical planning support based on the analytical results. The considered parameters include network parameters, like super area coverage, and mobile user mobility parameters, like moving mobile ratio and average mobile speed.

Communications and entertainment onboard a high-speed public transport system

Abstract: This article discusses architectural design at the conceptual/functional level of communication and entertainment services onboard a high-speed public transport system, such as a high-speed train, a transoceanic cruise ship, or even a mid- to long-range airplane. Existing commercial mobile communication services, such as AMPS and GSM, are inaccessible to passengers onboard these public transport systems. A hierarchical architecture is laid out to provide passengers with communication and entertainment services. Within this framework, the transport system itself becomes an entity of a mobile network whose connection with the infrastructure networks may be interfaced through either a land terrestrial microwave or a satellite communication system. The entire architecture is further divided into the mobile subsystem, the radio transport, and the land backbone network. Potential research topics are outlined.