Method and apparatus for transporting client signal in optical transport network
AssigneeHuawei Technologies Co., Ltd.
InventorsLimin DONG, Qiuyou Wu
Life of this patent
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Abstract
A method for transporting a client signal in an optical transport network (OTN) includes steps as follows. A byte number Cn of a client signal transported in a current OTN frame period is generated according to a client signal clock and a system clock. If the Cn of the current OTN frame falls in a certain range, a predetermined area in an optical channel payload unit-k (OPUk) overhead field is identified as normal, and the Cn is filled in the OPUk overhead field of the current OTN frame. Therefore, the reliability for transporting the client byte number can be improved and an OPUk overhead byte space needed for transporting the client signal byte number can be saved.
Claims20
A method for transmitting a client signal in an optical transport network (OTN), comprising:
- acquiring the client signal;
- extracting a client signal clock from the client signal;
- generating a client signal byte number Cn transported in an OTN frame period according to the client signal clock and a system clock;
- determining whether the client signal byte number Cn exceeds a range of client signal byte number transported in an OTN frame period;
- identifying if a first area in an optical channel payload unit-k (OPUk) overhead field of the OTN frame is normal;
- and
- filling, if the first area in the OPUk overhead field of the OTN frame is normal and if the Cn of the OTN frame falls in the range, a second area of the current OTN frame with the Cn filled in a previous OTN frame.
A method for receiving a client signal in an optical transport network (OTN), comprising:
- parsing an optical channel payload unit-k (OPUk) of an OTN frame to acquire a first area and a second area predetermined in an OPUk overhead field;
- acquiring an identifier in the first area and a client signal byte number Cn filled in the second area;
- comparing, if the identifier indicates that the Cn does not exceed the range of client signal byte number transported in one OTN frame period of the acquired client signal, whether the Cn filled in the second area exceeds a range of client signal byte number transported in one OTN frame period of the acquired client signal;
- and
- storing, if the identifier does not indicate that the Cn does not exceed the range of client signal byte number transported in one OTN frame period of the acquired client signal, the Cn filled in the second area, and restoring data of an OPUk payload area of a next OTN frame according to the stored client signal byte number Cn to acquire a client signal data stream.
An apparatus for transmitting a client signal in an optical transport network (OTN), comprising:
- a receiving unit adapted to acquire the client signal, and extract a client signal clock from the client signal;
- a client signal byte number Cn generating unit adapted to generate a client signal byte number Cn transported in an OTN frame period according to the client signal clock and a system clock;
- a determining unit adapted to determine whether the client signal byte number Cn exceeds a range of client signal byte number transported in an OTN frame period or not;
- and
- a setting unit adapted to perform at least one of setting an area of an optical channel payload unit-k (OPUk) of the OTN frame and filling the area of the OPUk of the OTN frame;
- a mapping unit adapted to map client signal bytes to an OPUk payload area;
- and
- a transmitting unit adapted to transmit an optical channel transport unit (OTU),
- wherein if the determining unit determines that the Cn of the OTN frame falls in the range, the setting unit is adapted to identify a predetermined area in an OPUk overhead field of the OTN frame as normal and fills the Cn in the OPUk overhead field, the mapping unit is adapted to map Cn client signal bytes to the OPUk payload area of a next OTN frame, and the transmitting unit is adapted to transmit an OTU comprising the OPUk to the OTN network.
An apparatus for receiving a client signal in an optical transport network (OTN), comprising:
- a receiving unit adapted to acquire an optical channel payload unit-k (OPUk) from the OTN;
- a first parsing unit adapted to parse the OPUk to acquire an identifier in a first area of an OPUk overhead field of an OTN frame;
- a second parsing unit adapted to parse the OPUk to acquire a client signal byte number Cn filled in a second area of the OPUk overhead field of the OTN frame;
- a first determining unit adapted to compare whether the Cn acquired through parsing by the second parsing unit exceeds a range of client signal byte number of the acquired client signal transported in one OTN frame period or not, if the identifier indicates that the Cn does not exceed the range of client signal byte number of the acquired client signal transported in one OTN frame period, and if not, trigger a storing unit to store the Cn acquired through parsing by the second parsing unit;
- a storing unit adapted to maintain the Cn, and store the Cn acquired through parsing by the second parsing unit, upon being triggered by the first determining unit;
- and
- a client signal recovering unit adapted to restore data of an OPUk payload area of a next OTN frame according to the client signal byte number maintained by the storing unit, so as to acquire a client signal data stream.
Dependencies are inferred from the claim text.