APPARATUS AND METHOD FOR ADAPTING A DIGITAL RADIOTELEPHONE SYSTEM TO INCREASED SUBSCRIBER TRAFFIC

摘要

A digital radiotelephone system using a vocoder for converting between analog voice and a digital format suitable for transmission over the air is proposed. In most situations, the fastest data rate is selected for optimal audio quality. When the system occupancy exceeds a certain threshold, some or all vocoders are instructed to switch to a low data rate in preparation for an increase in the number of communication channels, as sensed at a fixed site of the system. In addition, the portable subscriber unit can automatically change its vocoder data raid according to its battery charge status.