Zte Corporation

Jianxin Lu

Jie Su

Jidong Xu

Yunpeng Xie

Han Xu

Jinsong Bei

Zhiming Fu

Yuanling He

Jingxuan Wang

Jianzhang Chen

Meidong Zhu

Weiping Sun

A zeroing method and zeroing device for an optical time-domain reflectometer (OTDR) are disclosed. The zeroing method includes: before starting the optical time-domain reflectometer, when a laser device is in an off state, sending a zeroing signal; and performing zeroing processing according to the zeroing signal. In the embodiments of the present invention, the feedback zeroing can be performed on a receiving circuit by utilizing the idle time prior to a test or during the test, thus the influence of an offset voltage is reduced, and a problem of operational-amplifier zero drift also can be solved in the meantime, which improves a detectability of the OTDR, and overcomes a disadvantage that a manual zeroing method is not intelligent and a measured waveform introduced in an automatic zeroing method is bad.

Zeroing method and zeroing device for optical time-domain reflectometer

The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

Method and system for detecting fiber fault in passive optical network

The present invention provides a method and apparatus for implementing trunk optical fiber protection in EPON. According to the technical scheme of the present invention, activating an optical module at a master PON port, deactivating an optical module at a standby PON port, configuring a service for the master PON port, and synchronizing static data and dynamic data to the standby PON port; synchronizing and adjusting a value of an MPCP counter at the standby PON port according to a value of an MPCP counter at the master PON port; and carrying out fault detection, transmitting an operating state to the standby PON port when the fault occurs, and performing a master-standby switch of the PON ports. In accordance to the present invention, by means of adjusting the MPCP counter at the standby PON port and further setting a dedicated communication channel, the fast communication between the master and standby PON ports is realized, so that the ONU does not to re-register when performing the master-standby switch for implementing the trunk optical fiber protection process in EPON system, as a consequence, the service restoration time for protection switch is remarkably shortened, the system reliability is enhanced, and the performance of the protection switch is improved.

Method and apparatus for implementing trunk optical fiber protection in ethernet passive optical network (EPON)

The present invention discloses a method and system for accurate time transfer in PON. An Optical Line Terminal (OLT) ranges Optical Network Units (ONUs) and obtains ranging information, then, triggered by the periodic Pulse per n Second (PPnS), generates a PPnS timestamp based on the local reference counter and the Time of Day (TOD) above second; OLT transmits the ranging information, the periodic PPnS timestamp and TOD to ONUs; ONUs predicts the time of the next second according to said periodic PPnS timestamp, TOD and ranging information, and outputs the corresponding PPnS. The invention is characterized by the combination of the features of PON point to multi-point and PON ranging into its time transfer method, the high accuracy of time transfer, and the low hardware costs for OLT and ONU, as well as the extremely small bandwidth occupancy.

Method and system for transmitting time in passive optical network

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Shenzhen, China

Jianxin Lu