Showing papers on "Mobile telephony published in 1986"

Mobile Communications Design Fundamentals

Abstract: From the Publisher: The most recent addition to William C Y Lee's acclaimed series on mobile and cellular communications, Mobile Communications Design Fundamentals, Second Edition offers designers, researchers, and students an up-to-date, invaluable guide to the theoretical framework of mobile radio communications and how such systems are designed With an abundance of new material, this Second Edition covers leading-edge Personal Communications Service (PCS), microcell, and CDMA systems, providing all the theoretical and design knowledge and know-how needed to design with both present and future technology Useful as a professional handbook or as a senior/graduate level text, the book provides complete coverage of the differences between fixed and wireless radio systems, up to and including the new FCC-promoted PCS systems; an authoritative description of the mobile radio environment that gives engineers the necessary technical background to confidently select the appropriate radio technology; definitive, clearly presented design parameters for both the base and mobile units; troubleshooting approaches that help you anticipate the problems associated with each system and solve them when they arise; comprehensive guidelines for how to develop the system design and frequency plan and how to tackle all capacity issues, and new information on CDMA, a hot broadband radio technologyboosting microcell technology capacity with system planningbuilt in predictionanalyzing digital communication systemsand covering noncellular mobile radio systems, including those for data communication With more than half of the material in this new edition based on the author's own widely recognized research work, Mobile Communications Design Fundamentals is a book no one interested in the new wave in mobile communications can afford to miss

A statistical model of mobile-to-mobile land communication channel

Abstract: A statistical model applicable to a local area has been developed for mobile-to-mobile urban and suburban land communication channels. Using the model, the probability distributions of the received envelope and phase, spatial-time correlation function, and the power spectral density of the complex envelope have been developed.

Cellular mobile radio credit card system

Abstract: Cellular mobile telephone stations which are intended for installation and use in public transportation facilities, e.g., taxicabs, limousines, rental cars, etc. are equipped to support credit card billing of transient customers for use of the station services. The cellular pay stations, from the viewpoint of the serving cellular carrier facilities, are indistinguishable from standard cellular mobile stations. The activities of the credit card stations are supported by an administrative processor which is connected to a standard telephone line of the public switched telephone network. The cellular stations and the administrative processor exchange data messages over a standard telephone connection. The data messages are used to establish operating options and parameters of the credit card mobile stations, compile records in the administrative processor to permit the assignment of billing responsibility to transient customers for use of the stations and connected facilities, and control the stations for administrative and commercial reasons.

Signals in mobile communications: A review

Abstract: The signals in mobile communications are reviewed both in terms of the physical scenario and as the basis of the transfer function of the mobile channel. The transfer function is arranged to demonstrate the inherent limitations (the irreducible bit error rate effect) resulting from using single port antennas, in both narrow- and wide-band systems. A new model for the average source scenario at the urban-based (vehicular) mobile is determined and an analogous model for the base station is formulated. The models are useful for deriving diversity antennas.

Mobile communication equipment

Abstract: PURPOSE: To enable the interception of a mobile terminal equipment by providing an intercepting equipment where messages from callers are stored in a mobile communication network which is connected to a public telephone network and includes mutually connected exchanges for mobile communication. CONSTITUTION: A fixed terminal equipment 1 and a mobile communication exchange 3 are connected through the public telephone network 2 and a mobile communication exchange 3, a mobile communication exchange 4, and a home memory exchange 5 are connected mutually by a common line signal path 10-2; and a speaking circuit 11-2 is set in telephone service. The intercepting equipment 6 is connected to the home memory exchange 5. A radio base station 7 is connected to the mobile communication exchange 4 and connected to a mobile terminal device 8 through a radio channel. Even if there is an incoming call to the mobile terminal device and there is no answer, the message from the caller is sound-recorded and stored to finish this calling, and the mobile terminal subscriber is enabled to request the start and stop of interception and listen to the message. When there is no answer from the subscriber, the intercepting equipment 6 stores the message from the caller and also stores the message from the caller without calling the mobile terminal equipment according to the setting of the subscriber. Further, the operation mode in which the message from the caller is stored and the operation mode in which the stored message is reproduced are switched according to an indication from the mobile terminal equipment or fixed terminal equipment. COPYRIGHT: (C)1987,JPO&Japio

A shared service algorithm for a trunked mobile system

Abstract: A model has been developed and solved which captures the essence of the concept of mobile dispatch service. There are two types of users, dispatch and interconnect (calls routed from the public switched telephone network, of much longer holding times). Also, only some of the available repeaters can be used for interconnect traffic, and blocked interconnect calls are cleared. Dispatch calls, however, can access all repeaters, and then are queued if all repeaters are busy. One design decision involves a trade between blocking of interconnect calls and queueing of dispatch calls. A formula has been derived for both interconnect blocking probability and the mean dispatch queueing time to permit this trade. The results indicate that a good operating point is to have (N - a d )(rounded down) interconnected repeaters, where there are N total repeaters and a d Erlangs of dispatch traffic.

The prospect of a multi-beam mobile satellite communications system

Abstract: A multi-beam mobile satellite communications system is proposed. This system has been investigated for maritime and land mobile satellite communications services. The dominant characteristics of the system are as follows: 1 S-band (2.6/2.5GHz) is adopted, which is the most favorable frequency band under 10GHz judging from propagation characteristics. 2 An optimized weight budget design method of satellite is proposed, maximizing channel capacity of system. 3 A new transponder configuration method is adopted, which is tolerant of traffic variation.

Automobile telephone system

Abstract: PURPOSE: To variably set a telephone set used with priority by providing a controller bringing a 1st telephone set in a talking state in response to a 2nd switching means and bringing a 2nd telephone set in non-talking state when the 2nd telephone set is in the talking state. CONSTITUTION: The 1st telephone set F by mobile communication, the 1st telephone sets A∼C being fixed sets operated by the driver of the automobile and fixed by means of loudspeaker talking, the 1st switch means 50 setting which telephone set of 2nd telephone sets A∼C is used with priority, and the 2nd switching means 51 commanding the telephone set during talking to other telephone set, are provided. In case of an incoming call or a dialing, a telephone set with the priority by the 1st switching means 50 is brought into calling state by the action of a controller D. When the 2nd telephone sets A∼C are in the talking state in operating the 2nd switching means 51, the 1st telephone set F is brought into the calling enable state.Since the transfer from the 2nd telephone sets A∼C to the 1st telephone set F is conducted easily, the driver during driving applies the transfer operation. COPYRIGHT: (C)1988,JPO&Japio

Supervisory control of mobile telecommunications

Abstract: A telecommunications system including a mobile unit is protected from operator-induced disruption by disabling the operator-adjustable controls of the mobile unit and fixing the operating parameters of the mobile unit. A supervisory apparatus incorporating supervisory circuit elements replacing the adjustable circuit elements associated with the operator-adjustable controls may be plug-connected between the main chassis and the control head of the mobile unit.

Mobile set in broad band mobile communication system

Abstract: PURPOSE:To obtain an inexpensive system with similar functions without having expensive tracking exchange functions such as automatic location registration by giving plural service area identification codes and a mobile set identification number to one mobile set. CONSTITUTION:When a mobile set identification number corresponding to a service area (SVA) 3 is sent from a general telephone set (SUB) 1, a general telephone network (LNW) 2 receives and analyzes it, identifies the call to the SVA 3 to set the route 1 to a mobile communication exchange station (MTSO1) 6. The MTSO1 applies incoming control control through a part or all of the radio base station (MSB). The mobile set (MSS) 5 combines the service area identification code SID(R) and compares it with the service area identification code SID(S) stored through reception in advance. When SID(R)=SID(S), it is compared with the service area identification code in the mobile set class memory.

Production management system of article

Abstract: PURPOSE:To reproduce the original information into memory upon means missing by providing ROM pre-storing a number information inherent to a work in addition to memory means in mobile transmission device. CONSTITUTION:Upon read-out of information from RAM11 and ROM12 in mobile communication system 10 on the basis of a command from fixed communication system 30 in work station, under collapse of informations in RAM11 due to disturbance, a control computer 40 will command rewriting of production information corresponding with stored information because of unmatch between the production information and the information stored with corresponding to the number information. Consequently, production information is written similarly into RAM11 in mobile communication device 10 to reproduce the original production information in said device 10. Since the original production information can be reproduced in the mobile communication device on the basis of the inherent number information, highly reliable system can be realized.

Increasing Frequency Spectrum Utilization in Mobile Systems

Abstract: In mobile radio communication systems, one of the most significant problems is to use the radio frequency spectrum as efficiently as possible, because the radio frequency spectrum is finite. This paper classifies a variety of techniques for increasing frequency spectrum utilization. Next, it is clarified that our proposed ``new channel assignment algorithm'' is more efficient than other algorithms through simulation analysis.

Article manufacturing and controlling system

Abstract: PURPOSE:To eliminate stationary transmission of a fixed communication apparatus by detecting a work advancing into a range in which a mobile communication apparatus can receive communication, while generating the start command of wireless communication with the mobile communication apparatus to the fixed one CONSTITUTION:A mobile communication apparatus 10 has a function for storing and transmitting the production information of a car body 2 A fixed communication apparatus 20 performs wireless communication with the mobile one 10 through an antenna 21 Also, when the car body 2 advances on a transfer path 1 within a range DE in which the mobile apparatus 10 can receive the information of the fixed one 20, a detector 31 detects said information and a process controlling computer 40 for sending the signal commands the fixed apparatus 20 to start the wireless communication with the mobile one 10 Further, if the range DE is in front of an operation station the command of operation is given to the car body 2 on the basis of the production information of mobile apparatus 10 received by the fixed one 20 Also, if the range DE is immediately in rear of the operation station, command or the like is given to the fixed apparatus 20 to transmit the signal for write the production information related to the operational results in the operation station into the mobile apparatus 10

Lens antenna concepts for land mobile satellite communications

Abstract: The Mobile Satellite Program is being developed to provide needed communication links to rural areas. A critical component in the system is the antenna for the vehicle. This paper addresses the issue of reducing the cost of phased array vehicle antennas through the use of a lens feeding arrangement instead of through the use of phase shifters at each element. Theoretical performance of these lens fed arrays will be presented.

4800 B/S Speech Compression Techniques for Mobile Satellite Systems

Abstract: This paper will discuss three 4800 bps digital speech compression techniques currently being investigated for application in the mobile satellite service These three techniques, vector adaptive predictive coding, vector excitation coding, and the self excited vocoder, are the most promising among a number of techniques being developed to possibly provide near-toll-quality speech compression while still keeping the bitrate low enough for a power and bandwidth limited satellite service

A simulation study of in-building personal communications systems

Abstract: Radio communications within buildings has recently been of considerable interest. Radio communications within buildings are finding many new applications in the form of portable radio data distribution systems [PRDDS] for large office complexes and for portable telephone services [PRCS] in hospitals, industrial plants and warehouses. PRABX [Private Radio Automatic Branch Exchange] system has been proposed and its performance studied in terms of probability of call blocking, excess delay and average number of attempts required to access the system has been studied through simulation. The effect of fading on the access delay has also been studied.

Coherent versus noncoherent signaling for satellite-aided mobile communications

Abstract: The use of coherent versus noncoherent communications is an unresolved issue for the mobile satellite community. Should one select the more robust but less efficient noncoherent strategy for communications over satellite-aided mobile channels, or does the introduction of a space platform in the mobile link improve signal stability (both amplitude and phase) such that conventional coherent schemes become attractive? This publication tries to answer some of the questions by discussing the results from experiments using a coherent QPSK receiver. The issues discussed include items such as the measured performance in Rician fading, the link error floor in a fading environment, etc. The results are compared and contrasted with that of a noncoherent limiter/discriminator FM receiver.

Location of mobile subscriber station on land mobile radio with MSSC

Abstract: As for radio channel control of a cellular mobile communication system, location measurement is an important technique for determining the base station to be Connected with the mobile station. This paper describes the radio zone selection characteristic when a part of the control channel is time-shared by base stations and the reception level of each base station is measured at mobile stations. MSSC (Multitransmitter Simul/Sequential Casting) of control channels is proposed, which improves the location measurement and is suitable for a high-capacity system. The MSSC channel consists of simul-cast parts and sequential-cast parts. Its speech connection control sequence when applied to the cellular mobile communication system is shown. Next, the relation between the reception level variation characteristic in land mobile communication and the average reception level measurement accuracy when burst signals are received several times is studied. Both analytical results and laboratory experimental simulation results are shown. Finally, the zone selecting rate of a mobile station is calculated and the effect of the proposed control channel configuration is clarified.

Network design consideration of a satellite-based mobile communications system

Abstract: Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

Characteristics of Radiowaves at VHF/UHF for Mobile Communication in Suburban Areas

Abstract: Considering that there has been a need to give propagation curves for planning broadcast and mobile radio services in the VHF and UHF bands, propagation measurements were carried out at 52.5, 157, ...

Transmission loss guidelines for cellular mobile carrier interconnection

Abstract: The Cellular Services Compatibility Seminar (CSCS), has developed transmission loss guidelines for the three types of interconnection links between the Cellular Mobile Carrier (CMC) network and the Local Exchange Carrier (LEC) network. This paper documents the rationale behind these guidelines. The overall goal was to provide the capability for a call between a mobile user and a land user to have performance equivalent to that of a similar call between two land users. Other factors which were taken into consideration were consistency with existing transmission plans, compatibility with the capabilities of existing facilities and equipment, and flexibility for changes with the introduction of new technology. The actual loss values were based on expected speech power levels, minimizing the variability of losses through the Public Switched Network (PSN), and estimated customer perception of end-to-end voice service.