公开(公告)号：US10135531B1

公开(公告)日：2018-11-20

申请号：US15655441

申请日：2017-07-20

申请人： ADTRAN, Inc.

发明人： Daniel M. Joffe ,  John G. Brooks

IPC分类号： H04B10/50 ,  H04B10/2507 ,  H04B10/071 ,  H04B10/60

摘要： An optical transmission system transmits an optical signal over an optical path. Reflections of the optical signal are received at an optical detector which generates an analog reflection signal. The analog reflection signal includes both a desired portion and an undesired portion. Correlators of an OTDR system generate correlation values based on the analog reflection signal. A subset of the correlation values are associated with locations of the optical path that cause the reflections that result in the undesired portion of the reflected signal. A filter uses these correlation values to generate a cancellation signal that is subtracted from the analog reflection signal, reducing the undesired portion of the signal that must be processed.

公开(公告)号：US10887012B1

公开(公告)日：2021-01-05

申请号：US16262647

申请日：2019-01-30

申请人： ADTRAN, Inc.

发明人： Kevin W. Schneider ,  Leif J. Sandstrom ,  John G. Brooks ,  George Bekken

IPC分类号： H04B10/079 ,  H04J14/02 ,  H01S3/105 ,  H04B10/071 ,  G01S17/10

摘要： A laser tuning system includes an optical transmitter having a tunable laser that transmits optical signals at various wavelengths to an optical fiber through an optical component, which attenuates a range of wavelengths of the optical signal. An optical detector detects optical returns that have been reflected from the fiber at points beyond the optical component. A tuning control module analyzes the optical returns in order to provide a tuning value for tuning the laser to a desired wavelength. As an example, the laser may be tuned in order to maximize or otherwise increase the amount of optical power passing through the optical component.

公开(公告)号：US09806807B1

公开(公告)日：2017-10-31

申请号：US15207787

申请日：2016-07-12

申请人： Adtran, Inc.

发明人： Leif Sandstrom ,  Daniel M. Joffe ,  John G. Brooks ,  George Bekken

IPC分类号： H04B10/00 ,  H04B10/079 ,  H04B10/27 ,  H04B10/25

CPC分类号： H04B10/07955 ,  H04B10/0793 ,  H04B10/25 ,  H04B10/27 ,  H04B10/272

摘要： Methods, systems, and apparatus for automatically identifying rogue Optical Network Unit (ONU) are disclosed. In one aspect, an Optical Line Terminal (OLT) determines dark power on a fiber optic link over a period of time. For a given ONU, the OLT determines an optical power of high signals and an optical power of low signals received over the fiber optic link during a timeslot assigned to the given ONU, determines a modified optical power of the high signals and a modified optical power of the low signals based on differences between the optical power of the respective signals and the dark power, determines an extinction ratio based on a ratio of the modified optical power of the high signals relative to the modified optical power of the low signals, and identifies the given ONU as a rogue ONU when the extinction ratio is outside of a specified range.