ClassID:

227529

H04M1/74 - CPC Classification

Classification description:

Substation equipment, e.g. for use by subscribers; Interface circuits for coupling substations to external telephone lines with means for reducing interference; with means for reducing effects due to line faults

Sub-classes:
Recent Application in this class:
#1
20180103142
2018-04-12

Image forming apparatus to which noise counter-measure is applied

#2
20140307867
2014-10-16

Analog front-end transmitter and a connection method of an X-digital subscriber line having a pre-distortion mechanism

#3
20130266134
2013-10-10

Communication circuit employing optocoupler

#4
20120155618
2012-06-21

Apparatus, methods, and articles of manufacture to predict vectored digital subscriber line (DSL) performance gains

#5
20120069988
2012-03-22

Telephone system having reduced sensitivity to RF interference and related methods

#6
20120063588
2012-03-15

Method for correcting telephone signal degradation caused by the length of the analog line via the receiver

#7
20110092258
2011-04-21

Telephone system having reduced sensitivity to RF interference and related methods

#8
20110069031
2011-03-24

RF PULSE SYNCHRONIZATION FOR DATA ACQUISITION OPERATIONS

#9
20090270039
2009-10-29

Method and hybrid circuit for attenuating near-end crosstalk in a bidirectional signal transmission

#10
20090268797
2009-10-29

NONLINEAR DEVICE DETECTION

#11
20090080643
2009-03-26

Telephone system having reduced sensitivity to RF interference and related methods

#12
20080165157
2008-07-10

RF pulse synchronization for data acquisition operations

#13
20080117840
2008-05-22

Bridge circuit to suppress echoes in communication devices

#14
20070178868
2007-08-02

Telephone system having reduced sensitivity to RF interference and related methods

#15
20060067520
2006-03-30

Telephone line interface, side-tone attenuation circuit and method

#16
20050228647
2005-10-13

Method and system for controlling potentially harmful signals in a signal arranged to convey speech

#17
20050177365
2005-08-11

Transmitter-receiver

#18
20050041753
2005-02-24

Nonlinear device detection