INTERFACE BETWEEN MODEM AND TELEPHONE LINE

    公开(公告)号:JP2001177447A

    公开(公告)日:2001-06-29

    申请号:JP2000289844

    申请日:2000-09-25

    Abstract: PROBLEM TO BE SOLVED: To provide a configuration/method by which the dynamic range of a transmitted signal can be made flat so as to minimize return loss. SOLUTION: The above task can be solved by providing a digital pre- distorted filter in a data access device DAA in a MODEM chip set. Placing the pre-distorted filter at the outside of the DAA attains digital processing such as digital emulation of the impedance of a central station, thereby avoiding the effect by giving pre-distortion to a transmission signal. In the case of a digital emulation filter, placing the pre-distorted filter to the outside of an (A/D) loop/(D/A) loop can minimize noise.

    METHOD AND DEVICE FOR HOLDING LINE POWERED CODEC IN OFF- HOOK STATE THROUGH LOW POWER STATE BETWEEN LINE POWERED CODEC AND CALL BRIDGE

    公开(公告)号:JP2001203804A

    公开(公告)日:2001-07-27

    申请号:JP2000309804

    申请日:2000-10-10

    Abstract: PROBLEM TO BE SOLVED: To provide an inexpensive and reliable digital access arrangement(DAA), with which power can be partially supplied at least by available line currents provide by various countries. SOLUTION: This DAA adaptively enables operation suitable as the condition guarantee with power supplied from a telephone line, which it satisfies requested conditions related to a number of countries. Concerning a line power codec, register setting such as register setting for specified country, for example, is used for a startup procedure for an international line powered codec, and this is supplied and held with power from the low-voltage side (for example PC or modem side) of the line powered codec. Thus, the programmed state of the line powered codec can be kept even during the low line power state. Therefore, the line powered codec is not always returned into default state by reset caused by power loss within a telephone circuit.

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