Subscriber unit for compressing and transmitting high speed data

摘要

Two related voiceband compression techniques are employed in order to enable an RF subscriber unit to accommodate data signals of high speed voiceband modems and FAX machines. A High Speed Codec enables the subscriber unit to pass voiceband modem and FAX transmissions at up to 9.6 kb/s. An Ultra-High Speed Codec supports voiceband modem and FAX transmissions up to 14.4 kb/s. The High Speed Codec operates using three 16-phase RF slots or four 8-phase RF slots, and the Ultra-High Speed Codec operates using four 16-phase RF slots. Because these codecs transmit information over several RF slots which can be contiguous, the slots within RF communication channels are dynamically allocated. The Dynamic Time slot/Bandwidth Allocation feature detects and monitors the data transmission and forms a data channel from the necessary number of slots.