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Showing papers on "Mobile telephony published in 1996"


Journal ArticleDOI
TL;DR: The fundamental technical challenges and business motivations behind wireless position location systems are described, and promising techniques for solving the practical position location problem are treated.
Abstract: With the advances in wireless communications and low-power electronics, accurate position location may now be accomplished by a number of techniques which involve commercial wireless services. Emerging position location systems, when used in conjunction with mobile communications services, will lead to enhanced public safety and revolutionary products and services. The fundamental technical challenges and business motivations behind wireless position location systems are described, and promising techniques for solving the practical position location problem are treated.

673 citations


Patent
30 Aug 1996
TL;DR: In this article, a routing method for supporting ad-hoc mobile communications within a radio communications network is proposed, which comprises measuring the stability of the communications links between neighbouring mobile hosts using an associativity based characteristic.
Abstract: A routing method for supporting ad-hoc mobile communications within a radio communications network. The network comprises a plurality of mobile hosts including a source mobile host and a destination mobile host, and a plurality of radio communications links connecting together with mobile hosts. The method comprises measuring the stability of the communications links between neighbouring mobile hosts using an associativity based characteristic and selecting a communications route through the network from the source mobile host to the destination mobile host based on the stability of the communications links. The associativity characteristic is measured by each mobile host periodically transmitting and receiving identifier beacons (ticks) and updating the status of its corresponding links. The greater the number of ticks associated with a given link, the greater its stability. Use of the associativity characteristic enables the routing method to deal efficiently with mobile host migrations throughout the network.

560 citations


Patent
19 Jan 1996
TL;DR: In this article, the authors present an apparatus which allows an operator of a mobile communications unit, configured to receive and process signals generated by a Global Positioning System (GPS) and transmit them to a base communication unit, to be in voice communication with an operators of the base communications unit.
Abstract: The present invention provides for an apparatus which allows an operator of a mobile communications unit, configured to receive and process signals generated by a Global Positioning System (GPS) and transmit them to a base communications unit, to be in voice communication with an operator of the base communications unit, wherein the base unit operator can provide the mobile communications unit operator with geographic location information by voice communication while the base unit receives the processed GPS signals, translates these signals into the geographic location information and provides a visual image of the information to the base unit operator.

317 citations


Patent
Behruz Vazvan1, Janne Jormalainen1
08 Mar 1996
TL;DR: In this article, the authors proposed a mobile communication system combining several mobile communication networks which may belong to different mobile communication systems (31, 33, 34, 44), in which mobile terminals can operate and establish a connection in several mobile communications networks, and the parameters on the basis of which a mobile terminal decides on a handover include, in addition to the quality of the connection, at least one other parameter.
Abstract: The invention relates to a mobile communication system combining several mobile communication networks which may belong to different mobile communication systems (31, 33, 34, 44), in which mobile terminals (43) can operate and establish a connection in several mobile communication networks. It is characteristic of the invention that the parameters on the basis of which a mobile terminal (43) decides on a handover include, in addition to the quality of the connection, at least one other parameter. The parameter may be e.g. price, capacity, transmission speed, and availability. Primarily, we can think of selection based on price and quality, i.e. PQ selection, or selection base on price, capacity and quality, i.e. PCQ selection. When the system is provided with mobile pricing and price information arrangements with which the mobile stations may freely choose the most suitable or the most advantageous of the available connections, it is created a transparent subscriber market (40) for dual-mode or multimode terminals (43), which enhances rational competition and improves the efficiency of the use of capacity in mobile communications.

192 citations


Journal ArticleDOI
TL;DR: Overall mortality of a cohort of more than 250,000 portable and mobile telephone customers during 1994 is reported, and age-specific rates to be similar for users of the two types of telephones.
Abstract: Unlike mobile cellular telephones, in which the antenna is not part of the handset, a portable cellular telephone exposes the user's head to radio frequency energy transmitted from the antenna. This exposure has prompted concerns about potential biological effects, including brain cancer. As a first step in a record-based mortality surveillance of cellular telephone customers, we report on overall mortality of a cohort of more than 250,000 portable and mobile telephone customers during 1994. We found age-specific rates to be similar for users of the two types of telephones. For customers with accounts at least 3 years old, the ratio of mortality rates in 1994 for portable telephone users, compared with mobile telephone users, was 0.86 (90% confidence interval = 0.47-1.53). Language: en

144 citations


Patent
15 Jul 1996
TL;DR: In this article, a mobile communications system for permitting the communications of a mobile unit in proximity to a communications service having priority over the communication of the mobile unit is presented. But the system is not suitable for wireless networks.
Abstract: A mobile communications system for permitting the communications of a mobile unit in proximity to a communications service having priority over the communications of the mobile unit. An interference zone is formed around the priority communications site such that if the mobile unit were to transmit in the frequency band of the priority system, interference would be created with the operation of the priority receiver. In order to eliminate interference with the priority system by the mobile unit, a proximity detector determines if the mobile unit is located in the interference zone. Once the determination has been made that the mobile unit is located in the interference zone, the mobile unit alters its transmission to eliminate the interference of the mobile unit with the priority service. Interference may be eliminated, or in other terms, the interference zone may be altered, by ceasing the operation of the mobile unit, changing the operating frequency of the mobile unit, reducing the transmitting power of the mobile unit or by other means well known to those in the art.

129 citations


Proceedings ArticleDOI
25 Jun 1996
TL;DR: In this paper, the authors present recovery schemes for the failure of a mobile host in a mobile wireless environment, and the performance of the recovery schemes primarily depends on: the wireless bandwidth; the communicationmobility ratio of the user; and the failure rate of the mobile host.
Abstract: The mobile wireless environment poses challenging problems in designing fault-tolerant systems because of the dynamics of mobility, and limited bandwidth available on wireless links. Traditional fault-tolerance schemes, therefore, cannot be directly applied to these systems. Mobile systems are often subject to environmental conditions which can cause loss of communications or data. Because of the consumer orientation of most mobile systems, run-time faults must be corrected with minimal (if any) intervention from the user. The fault-tolerance capability must, therefore, be transparent to the user. The paper presents recovery schemes for the failure of a mobile host. It portrays the limitations of the mobile wireless environment, and their impact on recovery protocols. The adaptation of well-known recovery schemes are presented which suit the mobile environment. The performance of these schemes has been analyzed to determine those environments where a particular recovery scheme is best suited. The performance of the recovery schemes primarily depends on: the wireless bandwidth; the communication-mobility ratio of the user; and the failure rate of the mobile host.

108 citations


Journal ArticleDOI
B.H. Fleury1, P.E. Leuthold1
TL;DR: A systematic description of the propagation and simulation models developed within various European projects is given and the main features of these models and the rationale behind their elaboration are focused on.
Abstract: Detailed knowledge of radio propagation effects is a keystone for the development and performance assessment of mobile communication systems. Although a lot of investigations have already been carried out, there remains a need to gain deeper insight into the complex mechanisms which govern radio propagation. The authors first present a summary of the propagation mechanisms and discuss some issues related to radio channel parameters and measurement techniques. Then a systematic description of the propagation and simulation models developed within various European projects is given. The survey focuses on the main features of these models and the rationale behind their elaboration.

107 citations


Patent
19 Aug 1996
TL;DR: In this paper, a cellular phone system is described in which a cellular user (CPU) has a mobile phone with a predetermined amount of available airtime. But, the airtime transaction tracking interface (PATTI) does not track the number of airtime units.
Abstract: A cellular phone system in which a cellular phone user (CPU) has a cellular phone with a predetermined amount of available airtime. The CPU prepays for a particular number of airtime units. When a cell site receives a call from the CPU, the cell site communicates with a mobile telecommunications switching office (MTSO), which recognizes a unique serial number from the cellular phone. The MTSO directs the call to a prepaid airtime transaction tracking interface (PATTI). The PATTI then checks whether the CPU's account has any available airtime units and may indicate the number of units to the CPU. If none, the PATTI does not answer the call; otherwise, the PATTI connects the call and deducts airtime units until the call is disconnected.

96 citations


Book
01 Sep 1996
TL;DR: This chapter discusses the development of CDPD's Mobility Management Schemes, which addressed the challenges faced by the company in designing and implementing its flagship CDPD Network Services and Characteristics.
Abstract: List of Figures. Preface. Acknowledgments. Preliminaries. Basic Data Communication Model. Variations on a Theme. The Communications Channel. Channel Characteristics. Communication Protocols. Connection-Oriented and Connectionless Protocols. The OSI Reference Model. Layer 1 - The Physical Layer-Layer 2 - The Data Link Layer-Layer 3 - The Network Layer-Layer 4 - The Transport Layer-Layer 5 - The Session Layer-Layer 6 - The Presentation Layer-Layer 7 - The Application Layer. Protocols, Primitives, Services. Protocol and Service Data Units. Mobile Data Communications Entities. Summary. 1. Introduction to Mobility. What is Mobility? Basic Approaches to Mobility. Approach 1: Application Awareness-Approach 2: Directory Lookup-Approach 3: Mailbox Service-Approach 4: Administrative Redirection. Aspects of Mobile Communications. Mobile Network Access-Mobility Management. The Essential Challenge of Mobility Management. Knowing Where the Mobile is-Routing Data to the Mobile. Mobility Management is a Network Layer Function. Network Layer Addresses-Network Topology Changes-Routing Table Updates. Mobility Management Schemes. Permanent Address Scheme (PAS)-Temporary Address Scheme (TAS)-Embedded Network Scheme (ENS). Steps in the Mobility Management Process. Registration-Usage-De-registration. A Simple Taxonomy of Mobility. Type 0 Mobility: Stationarity-Type 1 Mobility: Location Independence-Type 2 Mobility: Transience. Range of Mobility. Channel-Cell-Mobility Area-Administrative Domain. Mobility is not Wirelessness. Wireless Considerations. Challenges of Mobility. Geography vs. Network Topology-Part-time Destinations- Moving Targets-Application Transparency-Name-to-Address Mapping-Security-Scale. Summary. 2. Introduction to Cellular Systems. The Ubiquity of Cellular. Radio Channels. The Cellular Concept. Cell Handoff. Cellular Channel Quality. Power Control. Advanced Mobile Phone System (AMPS). AMPS Channels-Roaming-AMPS Cellular Operation-AMPS Mobile Call Origination-AMPS Mobile Call Termination-AMPS Radio Resource Management (RRM)-AMPS Mobility Management. Data Transmission via AMPS. Digital Cellular Technologies. Europe: GSM and DCS 1800. Japan: PDC. North American Digital Standards. TDMA (IS-54/136). CDMA (IS-95,99). PCS: Back to the Future? PCS Licensing-PCS Standards-PCS Challenges. Summary. 3. Overview of CDPD. CDPD Background. CDPD Prototypes-"CDPD Lite" -CDPD Forum-CDPD Service Providers. Relationship of CDPD to other Cellular Data Initiatives. CDPD Services and Characteristics. CDPD Network Services-CDPD Network Support Services-CDPD Network Application Services. CDPD Design Goals and Considerations. Location Independence-Application Transparency- Multiprotocol Support-Interoperability-Minimal Invention- Optimal Usage of RF-Evolutionary Design-Open-Secure- Simple-Transparent to the Existing Cellular Voice Network. The CDPD Architectural Approach. The Three Key CDPD Interfaces. The A-Interface-The E-Interface-The I-Interface. CDPD Network Elements. The Mobile End System (M-ES)-The Mobile Data Base Station (MDBS)-The Mobile Data Intermediate System (MD-IS)-The Intermediate System (IS)-The Fixed End System (F-ES). CDPD Mobility Management. CDPD Radio Resource Management. CDPD Security. CDPD Accounting. Summary. 4. Mobility Management in Wide-Area Networks. The CDPD Mobility Vision. The CDPD Mobility Approach. CDPD Mobility Management Scope. CDPD Mobility Management Functions. CDPD Routing Architecture. CDPD Protocol Architecture. CDPD Support Protocol Architecture. CDPD Mobility Management Operation. Mobile Identification to Network - End System Hello (ESH)- Mobile Redirection Request (RDR)-Confirmation of service -Redirect Confirm (RDC)-Confirmation to M-ES - Intermediate System Confirm (ISC). CDPD Mobile Data Routing. Home MD-IS-Serving MD-IS. Intra-Area Mobility. Inter-area Mobility. Other Administrative Operations. Redirect Flush-Redirect Query and End System Query. Support Data Structures. Home Domain Directory-Registration Directory-Location Directory. Multicast Group Management. CDPD Multicast Service Definition-Multicast Registration- Multicast Authentication-Multicast Data Redirection-Multicast Data Forwarding-Multicast Service Characteristics. Broadcast Addresses. Selection Rationale. CLNP-Triangle routing. Summary. 5. Accessing the Mobile Network. The A-Interface. The Airlink Physical Layer. Shared Channel Environment. Approach 1: Token Passing-Approach 2: Demand Assigned with Reservation-Approach 3: Slotted Aloha-Approach 4: Carrier Sense Multiple Access with Collision Detection (CSMA/CD). The Airlink MAC Sublayer. Reed-Solomon Blocks-Busy/Idle Indicator-Decode Status Flag. M-ES State Machine. Airlink MAC Parameters. Min_Idle_Time-Min_count and Max_count-Max_blocks Parameter. Half Duplex Mobiles. The Airlink Data Link Protocol. Selective Reject-Removal of CRC-Addition of ZAP-Sleep Mode. SNDCF: Protocol Convergence. Segmentation and Reassembly-Multiplexing-Header Compression-V.42bis Data Compression-Data Encryption. How Data Moves Through Layers. Radio Resource Management. Model of Operation. Channel Hopping. Circuit-Switched Cellular Digital Packet Data. Circuit Switch CDPD Control Protocol. Summary. 6. Mobile Data Network Security. Introduction. Security Policy. Security Threats. Security Services and Mechanisms. Encipherment and Data Confidentiality-Digital Signatures- Authentication-Traffic Flow Confidentiality-Data Integrity-Key Management-Access Control-Network Layer Security Considerations. CDPD Security. CDPD Security Design Goals and Tradeoffs-CDPD Authentication-CDPD Confidentiality-CDPD Privacy. CDPD Security Design Rationale. CDPD Security Objectives-One-Way vs. Two-Way Authentication-The TunnelA A*s Data Confidentiality and Authentication-Considerations for Use of PKCS-Consideration of Other Approaches-End-to-End Security Services. 7. Mobile Network Support Services. Support Services Overview. CDPD Support Services. Network Management. Overview of System Management Framework-Systems Management Functional Areas-Relationship of Management Specifications to Functional Areas-CDPD Network Management. Usage Accounting. CDPD Usage Accounting-The CDPD Accounting Model- Accounting Meter-Serving Accounting Distributor (SAD)-Home Accounting Distributor (HAD)-Home Accounting Collector (HAC)- Consolidation Accounting Collector (CAC). Message Handling Service. Overview of Message Handling Services-Message Structure- Message Transfer Agent (MTA)-User Agent (UA)-Message Store (MS). Directory Services. The Directory-The Directory Model-The CDPD Directory Service. Summary. 8. Mobile Applications. Categories of Mobile Applications. Push or Pull: Mobile Application Information Access-Vertical or Horizontal Nature of Mobile Applications. Vertical Applications. Field Service-Mobile Professional-Transportation- Point-of-Sale (POS)-Telemetry-Government. Horizontal Applications. Messaging and email-Limited Size Messaging. Applications-Enabling Protocols. Limited Size Remote Operation Service (LSROS)-Status Notification Service-Subscriber Area Location Service. 9. Non-Cellular Approaches to Mobile Data Networking. Background. Wireless LANs and Metropolitan Networks. Infrared Systems-Narrowband RF Systems-Spread Spectrum Systems-Metricom Ricochet. Paging Systems. One-Way Paging Systems-Two-Way Paging Systems. Private Wireless Packet Data Systems. Public Wireless Packet Data Services. Advanced Radio Data Integrated System (Ardis)-RAM Mobile Data (Mobitex)-RadioMail. Satellite-Based Systems. Summary. 10. Future Directions in Mobility. Mobility under IPv4. The Mobile IP Standards Process-Overview of Draft Version 16 of the IETF IP Mobility Support-Implementations Based on Mobile IP Drafts. Mobility under IPv6. The IPv6 Standards Process-Overview of Mobility Support in IPv6. Comparison of Mobile IP and CDPD. Objectives, Goals and Assumptions-Technical Architecture and Design-Model and Terminology-Operational Assumptions- Standardization Process-Potential. Bibliography. Glossary. Index.

87 citations


Patent
13 Nov 1996
TL;DR: In this paper, the transmit signal power is continuously modified to move interference nulls to improve quality so that a fixed location user can receive a high quality signal, which can be applied to other digital technologies.
Abstract: A multiple antenna cellular network communicates with a mobile station over a plurality of antennas. The antennas are arranged in a plurality of positions to customize a cell or cells. A transceiver is coupled to the antennas and configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. A processor is coupled to the transceiver and configured to decode the inbound information and to encode the outbound information to communicate with the mobile station. In another embodiment, the transmit signal power is continuously modified to move interference nulls to improve quality so that a fixed location user can receive a high quality signal. Exemplary embodiments are provided for use with the Global Systems for Mobile Communication (GSM) protocol and can be applied to other digital technologies.

Proceedings ArticleDOI
08 Feb 1996
TL;DR: This 1 V DSPLSI with 26 MOPS and 1.1 mW/MOPS performance adopts a multi-threshold-voltage CMOS (MTCMOS) technique to reduce power during waiting periods.
Abstract: A low-power digital signal processor (DSP) is the key component for battery-driven mobile phone equipment since a vast amount of data needs to be processed for multimedia use. Reduced supply voltage is a direct approach to power reduction. This 1 V DSPLSI with 26 MOPS and 1.1 mW/MOPS performance adopts a multi-threshold-voltage CMOS (MTCMOS) technique. A small embedded power-management processor decreases power during waiting periods.

Patent
29 Apr 1996
TL;DR: In this article, the transceiver is coupled to a data bus for communicating the inbound and outbound information with the other elements in the base station, and the trunk module is also coupled to the control bus.
Abstract: A base station communicates with a plurality of mobile stations over a cellular network. In one embodiment, the base station includes a transceiver configured to receive inbound information from the mobile station and transmit outbound information to the mobile station. The transceiver equalizes and decodes the inbound information and encodes the outbound information. The transceiver is coupled to a data bus for communicating the inbound and outbound information with the other elements in the base station. The transceiver is also coupled to a control bus. An trunk module is coupled to the data bus and to a mobile services center. The trunk module communicates inbound and outbound information with the mobile services center. The trunk module is also coupled to the control bus. Finally, a central processor is coupled to the control bus to control the transceiver and the trunk module. A preferred protocol is Global Systems for Mobile Communication (GSM).

Patent
19 Jan 1996
TL;DR: In this paper, a mobile communication system is disclosed which precludes the necessity for mobile station to perform processing for microcell zone switching even when it moves from one microcell to another and which permits high-speed macrocell zone handover.
Abstract: A mobile communication system is disclosed which precludes the necessity for mobile station to perform processing for microcell zone switching even when it moves from one microcell zone to another and which permits high-speed microcell zone handover The service area of mobile communication is split into a plurality of macrocells; the macrocells are each subdivided into a plurality of microcells; a microcell base station equipped with a transmitting and receiving antenna and a power amplifier is installed in each microcell; a different communication channel is assigned to individual mobile station in the macrocell; even when the mobile station moves from one microcell to another, no channel handover takes place; and only when the mobile station moves from one macrocell to another, a mobile network control center which supervises the macrocell base stations effects channel handover

Book ChapterDOI
01 Jan 1996
TL;DR: A communication architecture framework which makes it possible to exploit the existing TCP/IP communication architecture but which also takes into account the specific features of wireless links, based on the principle of indirect interaction.
Abstract: Modern portable computers and wireless connections over a cellular telephone network have created a new platform for distributed information processing. We present a communication architecture framework which makes it possible to exploit the existing TCP/IP communication architecture but which also takes into account the specific features of wireless links. Our communication architecture is based on the principle of indirect interaction. The mediating interceptor, Mobile-Connection Host, is the bridge between the worlds of wireless and wireline communication. The interceptor also provides enhanced functionality that improves fault-tolerance and performance for applications aware of mobility. Prototypes of the architecture are implemented both for the Unix (Linux) and for the Windows (3.11) platform.

Patent
30 Jul 1996
TL;DR: In this article, the authors proposed a system for transmission of spatial diversity radio signals via a geostationary main communication satellite and one or more auxiliary satellites "colocated" in the same orbit.
Abstract: The invention concerns a system for transmission of spatial diversity radio signals via a geostationary main communication satellite and one or more auxiliary satellites "colocated" in the same orbit. The distance between an auxiliary satellite and the main satellite is in the range from 200 km to 400 km. The system includes conventional bidirectional transmission links between terrestrial mobile terminals and the main satellite and between the latter and a terrestrial station. Additionally, unidirectional transmission links are provided between the auxiliary satellites and the main satellite. Applications include a mobile communication service with portable terminals via a geostationary satellite.

Patent
David William James Holmes1
05 Dec 1996
TL;DR: In this paper, a mobile communication terminal device such as a cellular telephone is provided with a preliminary identifier stored in memory, which allows access to a cellular network for verification and provides essentially unique identification by the network, but is insufficient to allow further use of the network.
Abstract: A mobile communication terminal device such as a cellular telephone is provided with a preliminary identifier stored in memory. The identifier allows access to a cellular network for verification and provides essentially unique identification by the network, but is insufficient to allow further use of the network. During verification, the identifier is analyzed by a cellular network processor and a determination is made whether the cellular telephone should have restricted access to the network. Upon favorable completion of the identifier analysis, a signal may be transmitted to the cellular telephone that allows the cellular telephone to have less restricted access to the network.

Journal ArticleDOI
TL;DR: The requirements for third-generation cellular mobile radio systems such as Universal Mobile Telecommunications System (UMTS) and Future Public Land Mobile Telecommunications system (FPLMTS), which has been named International Mobile Telecommunications after the year 2000 (IMT-2000) are presented concisely.
Abstract: In Europe, the challenge of the design of third-generation cellular mobile radio systems has been taken numerous research and development activities in this field have been started. The authors try to give an overview of the European activities in this field. The article is organized in two parts. In the first part, the requirements for third-generation cellular mobile radio systems such as Universal Mobile Telecommunications System (UMTS) and Future Public Land Mobile Telecommunications System (FPLMTS), which has been named International Mobile Telecommunications after the year 2000 (IMT-2000) are presented concisely. Also, the importance and challenge of the multiple access design for such third-generation cellular mobile radio systems is explained. In the second part, numerous European research activities with focus on the multiple access design for third-generation cellular mobile radio systems are reviewed.

Book ChapterDOI
15 Dec 1996
TL;DR: Mobile communication offers many new opportunities, however, because of the mobility of the subscribers trustworthiness of data, reliability and security are major issues.
Abstract: Mobile communication offers many new opportunities. However, because of the mobility of the subscribers trustworthiness of data, reliability and security are major issues.

Patent
20 Nov 1996
TL;DR: In this paper, the location of a mobile communication unit within a network cellular communication system with power-based locator system is determined approximately by using a pre-stored map of locations of a plurality of base stations and the respective network cell coverage areas for those base stations.
Abstract: A network cellular communication system with power based locator system in which the location of a mobile communication unit within the network can be determined approximately. In particular, the power based locator system includes a pre-stored map of locations of a plurality of base stations within the network and the respective network cell coverage areas for those base stations. Each of the plurality of base stations is able to change the size of its respective cell by varying transmitter and receiver power levels. By incrementally changing its respective cell coverage area, the base station can effectively narrow down the region in which a mobile communication unit is located. The region information is correlated with the pre-stored map of locations to determine approximately where in the cellular communication network the mobile communication unit is located.

Patent
18 Dec 1996
TL;DR: In this paper, a radio communication system, efficient information provision services is obtained where various information is provided to mobile communication terminal devices separately from call services, update information on information to be provided is transmitted from a base station unit, and a mobile communication device receives the update information and then receives the desired information upon confirming that the desired Information has been updated.
Abstract: In a radio communication system, efficient information provision services is obtained where various information is provided to mobile communication terminal devices separately from call services, update information on information to be provided is transmitted from a base station unit, and a mobile communication terminal device receives the update information and then receives the desired information upon confirming that the desired information has been updated. Consequently, due to the ability to easily determine whether or not the information to be provided has been updated, the mobile communication terminal device need not receive all the information or connect to an information service center, but can efficiently use the information provision services.

Proceedings ArticleDOI
22 Sep 1996
TL;DR: In this article, the authors describe a design concept and the features of coherent DS-CDMA access which supports multimedia services and also flexible system deployment, where two-layer code assignment and transmit power control based on signal-to-interference (SIR) measurements are used.
Abstract: This paper describes a design concept and the features of coherent DS-CDMA access which supports multimedia services and also flexible system deployment. The testbed implemented for a series of field experiments near Tokyo and some measurement results are reported. In the proposed system, two-layer code assignment and transmit power control based on signal-to-interference (SIR) measurements are used. Pilot symbol-assisted coherent RAKE reception in the reverse link is employed to enhance the transmission quality. This paper also reports on the cell search algorithm used to accomplish rapid cell search under asynchronous cell site operation and low power consuming matched filter implementation. Finally, as an evolutionary step in future technology, an application of an interference canceling scheme and an adaptive beamforming scheme are presented in order to further increase the link capacity.

Journal ArticleDOI
TL;DR: The ACTS (Advanced Communications Technologies and Services) program will offer, in the period 1995-1998, service providers, communications operators, and equipment manufacturers greater opportunities to master and trial mobile and personal communications services and technologies.
Abstract: Vast importance is being placed in Europe on the development of third-generation mobile telecommunications systems, since it is expected that mobile and personal communications will become a key driver for growth and innovation in the next millenium as well as being a necessary building block of the wireless information society. Significant progress has been made since 1988 by a number of European Union funded R&D projects working toward the development of future generations of mobile communication concepts, systems, and networks. The ACTS (Advanced Communications Technologies and Services) program will offer, in the period 1995-1998, service providers, communications operators, and equipment manufacturers greater opportunities to master and trial mobile and personal communications services and technologies. From the user's perspective the ACTS program will strive to ensure that current mobile services are extended to include multimedia and broadband services, that access to services are made without regard to the underlying networks, and that convenient, lightweight, compact, and power-efficient terminals adapt automatically to whatever air-interface parameters are appropriate to the user's location and desired services.

Book
01 Sep 1996
TL;DR: Gain a better understanding of the propagation effects you're likely to encounter when working in fixed-link and mobile radio systems with this clear, practical guide.
Abstract: From the Publisher: Gain a better understanding of the propagation effects you're likely to encounter when working in fixed-link and mobile radio systems with this clear, practical guide. Without relying on complex explanations and obscure theory, the author first explores fixed-link propagation and then relates those concepts to the more complex situations you face in the mobile environment. You learn how and why propagation occurs, and discover useful techniques for minimizing transmission degradation and optimizing signal performance. Key topics include: • The radio refractive index (RRI) • Basic system planning techniques • The pros and cons of path loss predictions • The potential problems of in-building transmission • Why transmission constraints are greater in mobile than in fixed-link systems Especially useful for engineers who are new to mobile communications, technical managers needing an understandable overview, and graduate level students in communication engineering.

Patent
Markku Rautiola1, Jouni Mikkonen1
11 Sep 1996
TL;DR: In this article, the authors present an equipment and a method for providing in connection with the fixed communications network (1) a small cellular extension (4), wherein the same kind of radio frequency mobile communication devices (9) can be used as in regular cellular networks.
Abstract: The present invention concerns an equipment and a method for providing in connection with the fixed communications network (1) a small cellular extension (4), wherein the same kind of radio frequency mobile communication devices (9) can be used as in regular cellular networks (2), in other words, the radio interface (16) of the cellular extension (4) is similar to the radio interface (15) of the regular cellular networks (2). The cellular extension (4) comprises database means (11) for registering the subscribers and for transmitting the calls to the subscribers located in the cellular extension (4) based on the connections between the ISDN numbers of the cellular network determined for the cellular extension (4) and stored into the database means (11), and the IMSI codes of the subscribers. The invention doesn't require the same kind of signalling between the cellular extension and the regular cellular network as used in the regular cellular network (2) for implementing the data transfer between the mobile switching centers (5) and between the mobile switching centers (5) and the registers (7).

01 Nov 1996
TL;DR: A new approach to cellular network planning is presented that integrates teletraffic issues and radio engineering to automatically achieve optimized planning solutions and the core of this technique is the notion of demand nodes.
Abstract: As the demand for mobile communication services increases, network planning needs to be optimized to cope with both increased traffic demand and limited spectrum. In this paper we present a new approach to cellular network planning that integrates teletraffic issues and radio engineering to automatically achieve optimized planning solutions. The core of this technique is the notion of demand nodes. Experiments with the planning tool prototype ICEPT show the feasibility and effectivity of the approach.

Patent
13 Sep 1996
TL;DR: In this paper, the control channels used for the non-terrestrial mobile subscriber stations are selected such that the control signals transmitted in these channels are unrecognizable to the ground-based mobile subscriber station and cell site transmitter-receiver pairs.
Abstract: The multidimensional cellular mobile telecommunication system extends the usage of existing cellular mobile telecommunication radio frequencies allocated for ground-based communications to non-terrestrial mobile subscriber stations by adding an overlay of non-terrestrial cells of predetermined geometry and locus in space to the existing ground-based cellular cell site network. The polarization of the signals produced by the non-terrestrial antenna elements is a polarization that is different than and preferably substantially orthogonal to the polarization of the cellular radio signals produced by the ground-based antennas, such as a horizontal polarization, to thereby minimize the possibility of interference with the vertically polarized ground-based radio signals. Furthermore, the control signals exchanged between the non-terrestrial mobile subscriber stations and the non-terrestrial cell site controller are architected to avoid the possibility of interference with ground-based cell site transmitter-receiver pairs. In particular, the control channels used for the non-terrestrial mobile subscriber stations are selected such that the control signals transmitted in these channels are unrecognizable to the ground-based mobile subscriber stations and cell site transmitter-receiver pairs, so that even if broadcasts from a non-terrestrial mobile subscriber station reach a ground-based mobile subscriber station or cell site receiver, they cannot be interpreted and are rejected out of hand.

Patent
06 Dec 1996
TL;DR: In this paper, the location of a mobile communication unit within a network cellular communication system with power-based locator system can be determined approximately, in which each of the plurality of base stations is able to change the size of its respective cell by varying transmitter and receiver power levels.
Abstract: A network cellular communication system with power based locator system in which the location of a mobile communication unit within the network can be determined approximately. In particular, the power based locator system includes a pre-stored map of locations of a plurality of base stations within the network and the respective network cell coverage areas for those base stations. Each of the plurality of base stations is able to change the size of its respective cell by varying transmitter and receiver power levels. By incrementally changing its respective cell coverage area, the base station can effectively narrow down the region in which a mobile communication unit is located. The region information is correlated with the pre-stored map of locations to determine approximately where in the cellular communication network the mobile communication unit is located. Additionally, the present invention affords for substantially continuous connectivity of most or all mobile communication units to the network backbone, even when one of the plurality of base stations reduces the size and/or shape of its respective cell in order to locate a mobile communication unit.

Patent
Francois Sawyer1
29 Feb 1996
TL;DR: In this paper, a system and method for automatically determining and setting the optimum output power values on base station (B1-B10) and mobile station (M1-M10) radio channels in a cellular system is presented.
Abstract: A system and method for automatically determining and setting the optimum output power values on base station (B1-B10) and mobile station (M1-M10) radio channels in a cellular system. The invention sets power levels for fixed power radio channels, and sets initial and maximum power levels for variable power radio channels. The present invention utilizes data obtained from automatic digital voice channel power regulation in either the base station (B1-B10), or mobile station (M1-M10), or both when determining and setting optimum output levels on radio channels of the system.

Patent
25 Oct 1996
TL;DR: In this article, an integrated telecommunications system provides fixed and mobile satellite-based services via one or more geosynchronous satellites, where two-way user links are provided by the satellites to user terminals located throughout a geographical region.
Abstract: An integrated telecommunications system provides fixed and mobile satellite-based services via one or more geosynchronous satellites. Two-way user links are provided by the satellites to user terminals located throughout a geographical region. Additionally, the satellites provide two-way access links to gateway stations within the region, and also to a satellite network control center. The network control center controls bandwidth and power of the satellites to establish the user links and the access links. A mobile cellular telephone network provides mobile cellular telephone service to a subscriber that also has a user terminal. A gateway station includes a gateway station controller coupled to a mobile switching center, which, in turn, is coupled to a terrestrial network. The gateway station controller provides control signals route calls to either the user terminal or the mobile cellular telephone of the subscriber based on a single dialed number.