| 摘要 |
<p>The invention comprises a modem system for connecting computer systems and peripherals to telephone networks, such as the public switched telephone network (PSTN). The modem system contains a data access arrangement unit (100), referred to as a DAA unit, and a modem unit (110). The DAA unit is directly connected to a telephone line (105). Likewise, the modem unit is directly connected to a computer system or a peripheral (120) such as a printer or a fax machine. The digital interface between the DAA unit and the modem unit is infrared, radio frequency, LASER, or ultrasound. The DAA unit can be supplied by either direct current supplied by the telephone network, or can be supplied by an isolated power supply. <IMAGE></p> |
