# US 10,873,410 B2 · Reception device and method of detecting supervisory control signal

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- Number: US 10,873,410 B2
- Document ID: US10873410B2
- Status: Granted
- Kind: B2
- Application number: 15/900,128
- Filed: 2018-02-20
- Published: 2018-08-30
- Granted: 2020-12-22
- Earliest claimed: 2017-02-24
- Assignees: Fujitsu Limited
- Applicants: Fujitsu Limited
- Inventors: Yi Ge; Takeshi Hoshida; Hisao Nakashima; Tomofumi Oyama; Yuichi Akiyama
- Web page: https://patentgrep.com/patent/US10873410B2

## CPC

- H04J 14/0227: {Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation}
- H04B 10/0775: {Performance monitoring and measurement of transmission parameters}
- H04B 10/07957: {Monitoring or measuring wavelength}
- H04B 10/548: Phase or frequency modulation
- H04B 10/556: Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
- H04B 10/572: Wavelength control
- H04B 10/612: {for optical signals modulated with a format different from binary or higher-order PSK [X-PSK], e.g. QAM, DPSK, FSK, MSK, ASK}
- H04B 10/66: Non-coherent receivers, e.g. using direct detection
- H04J 14/0275: {using an optical service channel}
- 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

There is provided a reception device including a receiver configured to receive a wavelength-multiplexed optical signal so as to generate a wavelength-multiplexed signal, a filter configured to pass through the wavelength-multiplexed signal having a specific wavelength and an adjacent wavelength to the specific wavelength from the wavelength-multiplexed signal, and a processor configured to detect a specific signal having the specific wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter, and detect a first supervisory control signal having the specific wavelength and a second supervisory control signal having the adjacent wavelength from the wavelength-multiplexed signal having the passed through wavelengths by the filter.

## Claims

### Claim 1

A reception device, comprising:
a receiver configured to receive a wavelength-multiplexed optical signal so as to generate an electrical signal of the wavelength-multiplexed optical signal; and
a digital signal processor configured to include a plurality of electrical filters,
the plurality of electrical filters including a first electrical filter, a second electrical filter and a third electrical,
the first electrical filter configured to filter a first portion of the electrical signal corresponding to a specific wavelength of the wavelength-multiplexed optical signal,
the second electrical filter configured to filter a second portion of the electrical signal that corresponds to only a portion of a first adjacent wavelength of the wavelength-multiplexed optical signal that is adjacent to the specific wavelength from the wavelength-multiplexed optical signal,
the third electrical filter configured to filter a third portion of the electrical signal corresponding to a third portion of the electrical signal that corresponds to only a portion of a second adjacent wavelength of the wavelength-multiplexed optical signal that is opposite the first adjacent wavelength and adjacent to the specific wavelength,
a bandwidth of the first electrical filter is greater than a bandwidth of the second electrical filter and a bandwidth of the third electrical filter,
the digital signal processor
analyzes outputs of the first electrical filter, the second electrical filter and the third electrical filter to obtain identification numbers of a superchannel including the specific wavelength, the first adjacent wavelength, and the second adjacent wavelength,
compares the obtained identification numbers, and
recognizes a position within the superchannel of the specific wavelength based on the comparison of the identification numbers.

### Claim 2 (depends on 1)

The reception device according to claim 1, wherein a frequency shift keying-supervisory (FSK-SV) scheme is used as a modulation scheme of the electrical signal.

### Claim 3 (depends on 1)

The reception device according to claim 1,
wherein the output of the second electric filter is a first supervisory control signal and the output of the third electrical filter is a second supervisory control signal.

### Claim 4 (depends on 3)

The reception device according to claim 3, wherein the digital signal processor is further configured to:
offset the output of the second electrical filter and the output of the third electrical filter;
perform a down-sampling on the output of the second electrical filter and the output of the third electrical filter; and
detect an identification number of the first supervisory control signal and an identification number of the second supervisory control signal after the down-sampling is performed.

### Claim 5 (depends on 4)

The reception device according to claim 4, wherein the processor is further configured to:
detect each of the first supervisory control signal and the second supervisory control signal by monitoring offset frequency or a signal intensity of the output of the second electrical filter and the output of the third electrical filter.

### Claim 6 (depends on 3)

The reception device according to claim 3, wherein a wavelength setting command is superimposed on the first supervisory control signal and the second supervisory control signal, and
wherein the processor is further configured to set the specific wavelength, based on the wavelength setting command transmitted by a command relay scheme.

### Claim 7

A method of detecting a supervisory control signal, the method comprising:
receiving a wavelength-multiplexed optical signal so as to generate an electrical signal of the wavelength-multiplexed signal, by a receiver;
filtering with a digital signal processor including a plurality of electrical filters including a first electrical filter, a second electrical filter and a third electrical filter, the filtering including
first filtering with the first electrical filter a first portion of the electrical signal corresponding to
a specific wavelength of the wavelength-multiplexed optical signal,
second filtering with a second electrical filter a second and only a portion of the electrical signal that corresponds to only a portion of a first of adjacent wavelength of the wavelength-multiplexed optical signal that is adjacent to the specific wavelength from the wavelength-multiplexed optical signal,
third filtering with a third electrical filter a third portion of the electrical signal corresponding to a third portion of the electrical signal that corresponds to only a portion of a second adjacent wavelength of the wavelength-multiplexed optical signal that is opposite the first adjacent wavelength and adjacent to the specific wavelength,
a bandwidth of the first electrical filter is greater than a bandwidth of the second electrical filter and a bandwidth of the third electrical filter;
analyzing outputs of the first electrical filter, the second electrical filter and the third electrical filter to obtain identification numbers of a superchannel including the specific wavelength, the first adjacent wavelength, and the second adjacent wavelength,
comparing the obtained identification numbers; and
recognizing a position within the superchannel of the specific wavelength based on the comparison of the identification numbers.