DIGITAL DATA COMMUNICATION EQUIPMENT AND DIGITAL DATA COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To realize the digital data communication equipment and the digital communication method in which communication between a PSTN (public switched telephone network) analog data communication equipment and an ISDN(integrated service digital network) digital data communication is attained. SOLUTION: The equipment is provided with an ISDN line interface section 9, a PCM CODEC section 10 companding digital data by the companding algorithm used for the connection between an ISDN 2 and a PSTN 1, a data MO DEM section 12 modulating/demodulating the serial digital data as an analog signal communicated by the PSTN1 and a MODEM signal A/D converter and D/A converter section 23 that converts an output analog signal of a data modem section 12 into digital data and that output digital data of a PCM codec section 10 into an analog signal. Then the communication between analog and digital data communication equipments is attained.