# US 2021/0242956 A1 · Apparatus and adding and dropping method

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- Number: US 2021/0242956 A1
- Document ID: US20210242956A1
- Status: Published application
- Kind: A1
- Application number: 17/128,733
- Filed: 2020-12-21
- Published: 2021-08-05
- Earliest claimed: 2020-01-30
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Masahiro YUKI
- Web page: https://patentgrep.com/patent/US20210242956A1

## CPC

- H04J 14/0202: {Arrangements therefor}
- H04B 10/40: Transceivers
- H04J 14/0212: {using optical switches or wavelength selective switches [WSS]}
- H04J 14/02216: {by gain equalization}
- H04B 10/25: Arrangements specific to fibre transmission
- H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S)
- H04B: TRANSMISSION

## Abstract

An apparatus that adds and drops wavelength division multiplexed signal, the apparatus includes a memory and processor. The memory configured to store a first correspondence table indicating relationship with between an optical circuit type information and a first output level target value for a dropping circuit. The processor configured to determine an output level target value for the dropping circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.

## Claims

### Claim 1

An apparatus that adds and drops wavelength division multiplexed signal, the apparatus comprising:
a memory configured to store a first correspondence table indicating relationship with between an optical circuit type information and a first output level target value for a dropping circuit; and
a processor configured to determine an output level target value for the dropping circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.

### Claim 2 (depends on 1)

The apparatus according to claim 1, wherein
the memory stores a second correspondence table indicating relationship with between the optical circuit type information and a second output level target value for an adding circuit, and
the processor determines an output level target value for the adding circuit for each signal wavelength, based on the second correspondence table and the optical circuit type information of each signal wavelength.

### Claim 3 (depends on 1)

The apparatus according to claim 1, wherein the processor acquires optical circuit type information of the signal wavelength when the signal wavelength is added.

### Claim 4 (depends on 3)

The apparatus according to claim 3, further comprising
a transceiver configured to transmit to a first transmission device the acquired optical circuit type information.

### Claim 5 (depends on 1)

The apparatus according to claim 1, further comprising:
a transceiver configured to:
receive from a second transmission device the optical circuit type information, and
transmit to a first transmission device the received optical circuit type information.

### Claim 6 (depends on 1)

The apparatus according to claim 1, wherein
the memory stores a third correspondence table indicating relationship with between the optical circuit type information and a third output level target value for a pre-optical amplifier, and
the processor determines an average output level target value for the pre-optical amplifier based on the third correspondence table, and optical circuit type information of each signal wavelength.

### Claim 7 (depends on 6)

The apparatus according to claim 6, wherein
the memory stores a fourth correspondence table indicating relationship with between an optical circuit type information and a third output level target value for a post-optical amplifier, and
the processor determines an average output level target value for the post-optical amplifier based on the third correspondence table, and optical circuit type information of each signal wavelength.

### Claim 8 (depends on 7)

The apparatus according to claim 7, wherein
the output level target values for the dropping unit, the adding unit, the pre-optical amplifier, and the post-optical amplifier are set to values proportional to intensity change rates of optical circuits when an optical signal wavelength is added.

### Claim 9 (depends on 8)

The apparatus according to claim 8, wherein
gain target values for the pre-optical amplifier and the post-optical amplifier are determined from an input power measurement value, wavelength number information, and the average output level target values.

### Claim 10

An apparatus that adds and drops wavelength division multiplexed signal, the apparatus comprising:
a memory configured to store a first correspondence table indicating relationship with between an optical circuit type information and a first output level target value for an adding circuit; and
a processor configured to determine an output level target value for the adding circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.

### Claim 11

An adding and dropping method for wavelength division multiplexed signal, the method comprising:
storing a first correspondence table indicating relationship with between an optical circuit type information and a first output level target value for a dropping circuit; and
determining an output level target value for the dropping circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.

### Claim 12 (depends on 11)

The adding and dropping method according to claim 11, further comprising:
storing a second correspondence table indicating relationship with between the optical circuit type information and a second output level target value for an adding circuit, and
determining an output level target value for the adding circuit for each signal wavelength, based on the first correspondence table and optical circuit type information of each signal wavelength.