Alternative techniques for data compression which could be employed by location and communications systems to reduce bandwith requirements for radio transmission are examined. The authors note that selection of a data compression technique first requires the delineation of information requirements and definition of desired tolerance levels for data scope and flow. Data compression techniques are detailed within two generic concepts: (1) methods to reduce information volume; and (2) time sharing. Techniques to reduce the amount of data which must be transmitted are examined assuming the eventual system will not rely upon voice communications. Two alternatives are considered in which only changes in certain operational variables are transmitted. Such changes could correlate either with preceding inputs or with predictions. In the latter case, the system would estimate vehicle performance, and display only those transmissions which deviate from the projections. Several coding methods for data compression are also discussed, such as the "ten-code" used in voice communications between police units and dispatchers. Mathematical techniques used to predict vehicle performance are employed to reduce data requirements to those which indicate deviations from the predictions. Several interpolation compressors and sampling methods are analyzed with reference to bandwith utilization.

  • Corporate Authors:

    IIT Research Institute

    10 West 35th Street
    Chicago, IL  United States  60616
  • Publication Date: 1969-12

Subject/Index Terms

Filing Info

  • Accession Number: 00044203
  • Record Type: Publication
  • Source Agency: Urban Mass Transportation Administration
  • Files: TRIS, USDOT
  • Created Date: Jun 15 2000 12:00AM