Introduction of digital narrow-band channel technology into the existing cellular spectrum in the United States

This paper shows that narrow-band digital channels of N×5 kHz bandwidth can be gracefully introduced into a fully utilized cellular spectrum. The impact of introducing this technology on system blocking levels for new digital channel users and old analog FM channel users is quantified as a function of system growth and technology migration time frame. The degree of channel reuse for the new digital channels, as well as the old FM channels, is shown to decrease significantly from the beginning of the migration period to the end of the migration period. With the large spectral efficiencies afforded by narrow-band digital channels, the number of radio site locations needed to serve a system can be significantly reduced during the migration period, while any increase in radio sites beyond the migration period is at a significantly lower rate than before. Radio site reduction during the migration period is shown to be a function of subscriber growth, migration time frame, and channel bandwidth. Radio site growth after the migration period is shown to be a function of channel bandwidth and subscriber growth.