AUTOMATIC COMMUNICATIONS CONTROL SYSTEM (LAND MOBILE RADIO)

In FM Land Mobile Radio communication systems, the frequency spectrum below 300 Hz is essentially unused. A subaudible signaling format for use in this spectrum is examined. The technique utilizes direct FM modulation of the radio frequency carrier by near-Nyquist pulses. The ability to send data and audio together allows distribution of the signaling tasks among all system channels, thus reducing cost and increasing efficiency. From the trunk group of repeaters, one is selected as the "home channel" for each group of mobiles. Since each repeater is responsible for signaling on its home channel, this approach lends itself to distributed processing which requires only a small logic unit within each repeater. These logic units share system status information over a high-speed serial data bus. This architecture permits each repeater to be autonomous. A typical acquisition sequence in a simplified two-channel trunked system consisting of one repeater per channel is illustrated.

• Supplemental Notes:
  • Conference held in Dearborn, Michigan, 15-17 September 1980. Also published in HS-030 396 (IEEE-80CH1601-4; SAE-SP-90), "Convergence 80. IEEE Vehicular Technology Society Annual Conference (30th), International Conference on Transportation Electronics Proceedings," Utica, Michigan, 1980.
• Corporate Authors:

  Institute of Electrical and Electronics Engineers (IEEE)

  Operations Center, 445 Hoes Lane, P.O. Box 1331
  Piscataway, NJ  United States  08855-1331

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Grindahl, M L
• Publication Date: 1980

Media Info

• Pagination: 5 p.

Subject/Index Terms

• TRT Terms: Automatic control; Communication systems; Frequency modulation; Mobile communication systems; Mobile radio; Radio; Radio equipment
• Old TRIS Terms: Trunking
• Subject Areas: Safety and Human Factors;

Filing Info

• Accession Number: 00382062
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: IEEE-80CH1601-4, HS-030 471, SAE-SP-90
• Files: HSL, USDOT
• Created Date: Mar 30 1984 12:00AM