28th IEEE Vehicular Technology Conference最新文献

{"title":"Radio communication in subways and mines through repeater amplifiers and leaky transmission lines","authors":"R. A. Isberg","doi":"10.1109/VTC.1978.1622543","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622543","url":null,"abstract":"This paper is a report of the Author's visits to London Transport, the National Coal Board's Mining Research Establishment and the Cadley Hill Coal Mine where a \"daisy chain\" radio repeater and leaky feeder system is used for underground communication. A considerable amount of research and development of \"daisy chain\" radio repeater systems using leaky transmission lines has been accomplished in the United Kingdom by Dr. D. J. R. Martin of the National Coal Board's Mining and Research Establishment and Mr. Q. V. Davis of the University of Surrey. The basic \"daisy chain\" repeater system is similar in concept to coaxial cable telephone repeater and submarine communications cable systems which use amplifiers spaced at intervals to compensate for the attenuation of the cable. London Transport also has developed a prototype \"daisy chain\" radio repeater system which was commissioned into regular operation on a three mile section of the Bakerloo Underground railway in August, 1977. This system uses twenty-two 400 milliwatt repeater amplifiers spaced approximately 500 meters apart along leaky coaxial transmission lines which are supported from the walls of the subway tunnels and under the platforms of passenger stations. The other half of the Bakerloo Underground is equipped with three conventional twenty-five watt base stations feeding tee sections of leaky coaxial transmission line. While both systems perform satisfactorily, the section that is equipped with \"daisy chain\" amplifiers does not have transition zones between the tee sections of leaky cable, requires fewer telephone control lines and uses a simpler control system. By combining the techniques of the on-channel signal booster and the \"daisy chain\" repeater system using selective filters and wide band linear amplifiers it should be possible to extend signals received from base stations above ground into subways. This would satisfy the requirements for providing, at a much reduced cost, multi-channel radio communications for not only the transit system but also police, fire, para-medical and paging services.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134628570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land mobile radio system performance model for VHF and higher frequencies over irregular terrain","authors":"E. Haakinson, R. D. Jennings","doi":"10.1109/VTC.1978.1622592","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622592","url":null,"abstract":"A model is described which may be used to predict land mobile radio system performance over irregular terrain. The model uses a semi-empirical formulation to calculate propagation losses from a selected base-station location to surrounding mobile locations within a variable-size \"box\" not exceeding two degrees latitude by two degrees longitude. Terrain data is obtained from a computer-accessible data base. The output is a plot showing contours of constant propagation loss, power density, or available received power.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"253 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124171642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic vehicle location system selection","authors":"G. Wilson","doi":"10.1109/VTC.1978.1622504","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622504","url":null,"abstract":"With the advent of commercial automatic location systems that have the potential of improving the management of mobile unit operations, law enforcement agencies are expressing a growing interest in the use of technology to improve their responsiveness to community needs, to enhance patrolman safety, and to provide data for the evaluation of operational strategies. When employed in police operations, an automatic vehicle location system becomes one element of the overall police system. The characteristics of such overall operations, the planned uses for the location system and even the city layout and topography influence system parameters and must be afforded consideration in the selection process. This paper describes the relationships between operational requirements and system performance parameters and identifies the technical and administrative factors that should be considered in the selection and deployment of cost-effective automatic vehicle location systems.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"162 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129200599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Speed, acceleration and pulse prediction calculations on test vehicles with wheel pulse generators","authors":"C.H. Kraft","doi":"10.1109/VTC.1978.1622542","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622542","url":null,"abstract":"The use of microprocessors for calculation of dynamic quantities such as speed and acceleration on land based test vehicles which use wheel pulse generating probes is discussed. Methods of pulse prediction and windowing are presented along with formulas for determining the existance of the next pulse. Considerations in actual implementation of a microprocessor for these tasks are brought out.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115451053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"County emergency medical communications in a high density urban area with dynamic frequency assignments","authors":"W. Beaman, H. K. Spence, R. Flanagan, G. E. Austin","doi":"10.1109/VTC.1978.1622535","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622535","url":null,"abstract":"The County of San Mateo, California, through its Health and Welfare Department, with cooperation from the Communications Division of the Department of General Services, has purchased and installed a County-wide Communications System, as planned by the Emergency Medical Care Committee, for the expressed purpose of allowing those personnel responding to an emergency medical need to cooperate fully and quickly to that need. Since San Mateo County is one of nine counties in the San Francisco Bay Emergency Medical Service (EMS) Area, it was extremely critical that proper planning of a dynamic communication system responsive to the users be done while still accomplishing regionwide cooperation for the dynamic use of all UHF Med channels. The geographic and demographic conditions of the County are similar to other Bay Area counties, in that major population centers and large cities are clustered together on flat to semi-hilly lands, usually along San Francisco Bay, while a range of mountain ridges splits the County into several difficult areas for radio communications. Much of the south and western parts of the County are rural, rugged areas along a sparsely populated coast. The north and eastern portions are well populated living and industrial areas, which have high growth rates. Therefore, the EMS Comunication System was designed to help fulfill the Emergency Medical Care Committee's objective of providing a prompt, efficient, and high level of care to those encountering a medical emergency anywhere in the County.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114458494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Chicago developmental cellular system","authors":"D. Huff, J. Kennedy","doi":"10.1109/VTC.1978.1622511","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622511","url":null,"abstract":"","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114473728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraints upon the development of the nationwide land mobile radio system","authors":"R. Eckert, P. M. Kelly","doi":"10.1109/VTC.1978.1622575","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622575","url":null,"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.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127636894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suppression of radio frequency interference at the distributor rotor gap","authors":"W. Kuo","doi":"10.1109/VTC.1978.1622595","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622595","url":null,"abstract":"Generally, for a given spark gap length, lower breakdown voltage of the gap corresponds to a lower RFI level. Mechanisms which lead to the reduction of breakdown voltage at the spark gap by two techniques are discussed. The first technique involves the addition of a pointed electrode near the cathode, while the second technique involves the presence of bulk dielectric material on the cathode surface near the gap. Practical distributor rotor designs based on these techniques for effective RFI control are described.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123651047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loran C tracking of land vehicles using microcomputers","authors":"A. El-Sawy, J. Feuerstein, R. Mayer","doi":"10.1109/VTC.1978.1622526","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622526","url":null,"abstract":"The concept, design, and evaluation of two similar Loran C land vehicle tracking systems developed by MITRE are presented. One system was developed to provide field demonstrations of applications of Loran C location techniques such as highway inventory accounting, highway accident site recording, control and dispatch of emergency and law enforcement vehicles, and control of mass transit vehicles. The second system was configured to automatically display the reported status and location of two emergency medical service (EMS) vehicles to aid in more efficient dispatch and control functions. The Loran coordinates of the vehicle are transmitted to the base station where a microcomputer resolves the Loran coordinates into geographic/display coordinates and displays the vehicle location. Accurate Loran C land vehicle tracking requires calibration of the Loran signals to respective geographic or map coordinate locations. The two systems being discussed use a linear approximation of the hyperbolic Loran grid. The Loran coordinate to display screen position algorithm is, therefore, linear. Automatic tracking Loran receivers are installed in the vehicles. The receivers have been modified to output an audio band signal containing the two Loran time coordinates, the internal status of the receiver, a vehicle identification code, and 1 of 8 vehicle status codes entered on a manual keyboard located in the vehicle. A transmitter key control is also available. Commercial land mobile radios are used for transmission and reception of the audio signal. The land mobile receiver output at the base station is demodulated by a commercially available demodulator and input to the microcomputer on a serial port. After initialization of the system, map display, tracking, screen refresh, and status reporting are all automatic.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125543579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A prediction for the next sunspot cycle","authors":"H. H. Sargent","doi":"10.1109/VTC.1978.1622589","DOIUrl":"https://doi.org/10.1109/VTC.1978.1622589","url":null,"abstract":"A number of predictions for the next sunspot cycle (Cycle 21) are examined and tabulated. It is shown that published predictions, to date, have been predominately in favor of a low sunspot cycle (120 or less). The prediction method of Ohl is discussed. His method is applied, using one hundred and ten years of sunspot and geomagnetic data to give a forecast for Cycle 21. The multiple regression equation developed is shown to be highly significant. The prediction made here specifies a smoothed sunspot maximum of 154, occurring in early 1980. The 95% confidence interval for the prediction is plus or minus 50, and the probability of exceeding 120 is 92.6%. Such a high maximum would be significantly higher and earlier than most previously published predictions. If this forecast is accurate, Cycle 21 will be equivalent to, or greater than, the second largest sunspot cycle observed in the past century. This will have a profound effect on high-frequency communications. Some consequences of such a large cycle are discussed and parallels are drawn to Cycle 18 (maximum of 152). Finally, the latest observed sunspot values are presented to demonstrate the validity of the prediction early in the cycle.","PeriodicalId":264799,"journal":{"name":"28th IEEE Vehicular Technology Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1978-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122256633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}