Iowa public safety mobile communications system "Technology on the move"

This paper describes in detail the technical and operational aspects of the Iowa Public Safety Mobile Communications System. The mobile communications system is unique in design and applies many technological advances to land mobile applications. This system was designed by State of Iowa Electronic Engineers. This is not a turnkey system; the system is comprised of components representing 27 different manufacturers. Many components were uniquely designed or uniquely applied to mobile technology. The Iowa System makes near maximum use of available 155 MHz spectrum. It utilizes 15 KHz adjacent channel spacing and its repeater channels are as close as 195 KHz at co-located sites. Two repeaters and one simplex channel operate simultaneously within a 1 MHz spectrum.