Showing papers on "Mobile telephony published in 1978"
TL;DR: The spectral efficiency of the spread-spectrum scheme may exceed those of the narrow-band schemes by a factor of almost five, and more ambitious bit-rate-reducing speech digitization methods could improve still further on these figures.
Abstract: A spread-spectrum technique for cellular high-capacity mobile communications is described and some results from an analytic study are summarized. The technique uses a very large set of frequency-hopped signals which are designed for minimal mutual interference. No synchronization of the mobile units is required, and each user is permanently assigned his own signal, which serves as an identifying signal and as a carrier for the biphase-modulated digital message. The spectral efficiency of the spread-spectrum system is analyzed and compared with the efficiencies of developmental FM/channel reuse schemes currently under construction in the U.S. and Japan. It is concluded that even with relatively simple speech digitization schemes, the efficiency of the spread-spectrum scheme may exceed those of the narrow-band schemes by a factor of almost five. More ambitious bit-rate-reducing speech digitization methods could improve still further on these figures. Additional benefits of the spread-spectrum scheme include immunity from fading and interference, more consistent speech quality, simpler system control algorithms, and more flexible blocking properties under overload conditions.
330 citations
01 Jan 1978
48 citations
TL;DR: In this paper, an offset carrier frequency allocation method is proposed for a high capacity land-mobile telephone system which employs a small zone technique, and the simulation test results are presented which determine the design parameters.
Abstract: In a high-capacity land-mobile telephone system which employs a small zone technique, it is advantageous to provide control channels separate from voice channels. We first review two control channel allocation methods: the individual control zone system and the multiple control zone system. From the viewpoints of efficient frequency utilization and reliable call processing, the multiple control zone system is shown to be preferable. It is experimently verified that an offset carrier frequency strategy is well suited to the realization of this system. Simulation test results are presented which determine the design parameters. Offset carrier frequency allocation methods concerning three types of fundamental zone configuration are derived. The carrier frequency synchronization and the phase adjustment of the modulation signals are investigated for the actual system construction.
30 citations
TL;DR: The 800-MHz band land mobile telephone system which is going into service in Tokyo and other major cities is described, characterized by an ordered array of cells which allows each radio channel to be reused by spacing at an appropriate coordination distance.
Abstract: The 800-MHz band land mobile telephone system which is going into service in Tokyo and other major cities is described. This system is characterized by 1) an ordered array of cells which allows each radio channel to be reused by spacing at an appropriate coordination distance in a wide service area (cellular system), 2) development of a new higher frequency band, and 3) a fully automatic exchange system integrated with the ordinary telephone network. Field tests have been carried out in the Tokyo metropolitan area since 1975 and have now been brought to a successful completion.
18 citations
Patent•
15 Feb 1978
TL;DR: In this article, a multitransmitter digital signaling system for mobile communications consisting of a plurality of base stations, different waves are superposed on the digital information signals in adjacent base stations and carrier waves of the same frequency are angularly modulated by the superposed signals at the same modulation index and simultaneously transmitted from the base stations to one service area.
Abstract: In a multitransmitter digital signaling system for mobile communications consisting of a plurality of base stations, different waves are superposed on the digital information signals in adjacent base stations and carrier waves of the same frequency are angularly modulated by the superposed signals at the same modulation index and simultaneously transmitted from the base stations to one service area.
14 citations
TL;DR: A model for the analysis of connectivity as a function of time in a store-and-forward packet system employing radio links is presented and used to solve for parameters of interest.
Abstract: A Packet Radio Network is a store-and-forward packet system employing radio links. A Mobile Packet Radio Network generalizes this system by allowing every radio unit to be independently in motion. In this paper a model for the analysis of connectivity as a function of time in such a network is presented and used to solve for parameters of interest. The model and the related analysis are guides for developing procedures for monitoring connectivity.
8 citations
Patent•
29 Jun 1978
TL;DR: In this article, the authors propose to make it possible to make an operation test of communication facilities of the mobile station from the base station, by automatically responding to the signal from the BS from a mobile station.
Abstract: PURPOSE:To make it possible to make an operation test of communication facilities of the mobile station from the base station, by automatically responding to the signal from the base station from the mobile station.
4 citations
Patent•
28 Mar 1978
TL;DR: In this article, the authors propose to make the fault detection quickly by making unnecessary the test personnel of control station and shortening the test time, through the provision of test functions in mobile stations and the control station.
Abstract: PURPOSE:To make the fault detection quickly by making unnecessary the test personnel of control station and shortening the test time, thru the provision of test functions in mobile stations and the control station.
3 citations
Patent•
25 Nov 1978
TL;DR: In this paper, the authors proposed a scheme to realize a shortened processing time and improved services with the need for an intra-office signal transfer with each exchange eliminated, by registering mobile subscribers all over again through the signal control of an indormation storage office.
Abstract: PURPOSE:To realize a shortened processing time and improved services with the need for an intra-office signal transfer with each exchange eliminated, by registering mobile subscribers all over again through the signal control of an indormation storage office.
3 citations
TL;DR: In this paper, mobile telephone control unit design guidelines for the Advanced Mobile Phone Service have been developed based on driving behavior, user preference, automobile environment, and calling procedure considerations, and they illustrate their application by reviewing five control units design approaches.
Abstract: Mobile telephone control unit design guidelines for the Advanced Mobile Phone Service have been developed based on driving behavior, user preference, automobile environment, and calling procedure considerations. This paper explains these guidelines and illustrates their application by reviewing five control unit design approaches.
Patent•
10 Jan 1978
TL;DR: In this paper, the time in which the noise is existing between a base station and a mobile station is shortened, thereby reducing the discomfort to the subscriber at the mobile station side.
Abstract: PURPOSE:The time in which the noise is existing between a base station and a mobile station is shortened, thereby reducing the discomfort to the subscriber at a mobile station side.
22 Mar 1978
TL;DR: A satellite land mobile system using mobile radios in the UHF band, and Ku-band "Communications Routing Terminals: (earth stations) for a nationwide connection from any mobile locations to any fixed or mobile location, and from any fixed location to any mobile location is proposed.
Abstract: A satellite land mobile system using mobile radios in the UHF band, and Ku-band "Communications Routing Terminals: (earth stations) for a nationwide connection from any mobile location to any fixed or mobile location, and from any fixed location to any mobile location is proposed. The proposed nationwide satellite land mobile service provides: telephone network quality (1 out of 100 blockage) service, complete privacy for all the users, operation similar to the telephone network, alternatives for data services up to 32 Kbps data rates, and a cost effective and practical mobile radio compatible with system sizes ranging from 104to about 4 × 106users. Seven satellite alternatives (ranging from 30' diameter dual beam antenna to 210' diameter 77 beam antenna) along with mobile radios having a senitivity figure of merit (G/T) of -15dB/°K are considered. Optimized mobile radio user costs (including mobile radios, earth terminals, satellite terrestrial tails, service and maintenance, and operating costs) are presented as a function of the number of users with the satellite and mobile radio alternatives as system parameters. The configuration of the mobile radios' "Communications Routing Terminals" along with the appropriate networking and signaling arrangements are included.
Patent•
11 Nov 1978
TL;DR: In this paper, the authors proposed to improve the efficiency in use of channels and obtain the economical system which has resistance to a radio disturbance, by selective y using a calling channel and talking channel at any time, depending on the state in using radio channels.
Abstract: PURPOSE:To improve the efficiency in use of channels and to obtain the economical system which has resistance to a radio disturbance, by selective y using a calling channel and talking channel at any time judging from the state in use of radio channels.
22 Mar 1978
TL;DR: In this article, the authors present five control unit design approaches for high capacity mobile telecommunication systems based on driving behavior, user preference, automobile environment and calling procedure considerations, and illustrate their application.
Abstract: Mobile telephone control unit design guidelines for the High Capacity Mobile Telecommunications System have been developed based on driving behavior, user preference, automobile environment and calling procedure considerations. This paper explains these guidelines and illustrates their application by reviewing five control unit design approaches.
22 Mar 1978
TL;DR: The modeling should generate the operational and regulatory requirements that candidate systems under consideration must possess in order for them to be responsive to user needs and national objectives and the two activities constitute a balanced systems engineering effort in support of the continued development of land mobile radio.
Abstract: An extension of the techniques of game theory is proposed for modeling the interaction that takes place in land mobile radio docket proceedings concerned with system evolution. The expectation is that, to the extent that the model can be structured as a valid representation of the actual interaction, the modeling should generate the operational and regulatory requirements that candidate systems under consideration must possess in order for them to be responsive to user needs and national objectives. The modeling process can be looked upon as a time compression of what otherwise would involve years of sequential docket proceedings. With the results of the modeling available, it should be possible to structure actual dockets to handle complex and comprehensive issues in considerable detail and with reasonable dispatch. Essential to the integrity of the modeling techniques is the requirement that the system alternatives which are evaluated must represent realistic representations of what can be achieved with practical projections of technological advances. For this reason there is a requirement that a searching inquiry into the implications to land mobile radio of advancing technology be carried on in parallel with the modeling activity. The two activities, then, constitute a balanced systems engineering effort in support of the continued development of land mobile radio.
30 Nov 1978
TL;DR: The intent is to provide the mobile users with a grade of service consistant with the requirements for remote, rural (perhaps emergency) voice communications, but which approaches toll quality speech.
Abstract: The viability of mobile communications is examined within the context of a frequency division multiple access, single channel per carrier satellite system emphasizing digital techniques to serve a large population of users. The intent is to provide the mobile users with a grade of service consistant with the requirements for remote, rural (perhaps emergency) voice communications, but which approaches toll quality speech. A traffic model is derived on which to base the determination of the required maximum number of satellite channels to provide the anticipated level of service. Various voice digitalization and digital modulation schemes are reviewed along with a general link analysis of the mobile system. Demand assignment multiple access considerations and analysis tradeoffs are presented. Finally, a completed configuration is described.