Reduction of wavelength selective switch (wss) filter-based impairment using differentiated channel modulation formats

Patent metadata

Field	Value
Publication number	US-2016192042-A1
Application number	US-201414586106-A
Country	US
Kind code	A1
Filing date	Dec 30, 2014
Priority date	Dec 30, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

A method may include transmitting, by an optical device, a first set of channels using a first modulation format. The first set of channels may be attenuated during transmission by a filter associated with a wavelength selective switch. The method may further include transmitting, by the optical device, a second set of channels using a second modulation format. The second set of channels may be attenuated during transmission by the filter associated with the wavelength selective switch. The first set of channels and the second set of channels may be included in a super-channel. The first modulation format may be selected based on a first signal quality factor associated with attenuation by the filter associated with the wavelength selective switch. The second modulation format may be selected based on a second signal quality factor associated with attenuation by the filter associated with the wavelength selective switch.

First claim

What is claimed is:

1 . A method, comprising:
transmitting, by an optical device, a first set of channels using a first modulation format,
the first set of channels being attenuated during transmission by a filter associated with a wavelength selective switch; and
transmitting, by the optical device, a second set of channels using a second modulation format,
the second set of channels being attenuated during transmission by the filter associated with the wavelength selective switch,
the first set of channels and the second set of channels being included in a super-channel,
the first modulation format being selected based on a first signal quality factor associated with attenuation by the filter associated with the wavelength selective switch,
the second modulation format being selected based on a second signal quality factor associated with attenuation by the filter associated with the wavelength selective switch.

2 . The method of claim 1 , where the first modulation format and the second format are different.

3 . The method of claim 1 , where the first modulation format is one of:
a phase-shift keying format; or a quadrature amplitude modulation format.

4 . The method of claim 1 , where the first signal quality factor is a first bit error rate and the second signal quality factor is a second bit error rate, further comprising:
monitoring the first set of channels; determining, based on monitoring the first set of channels, that the first bit error rate associated with the first set of channels does not satisfy a threshold; and causing the first modulation format to be adjusted based on determining that the first bit error rate associated with the first set of channels does not satisfy the threshold.

5 . The method of claim 1 , further comprising:
causing the first modulation format to be changed to another modulation format associated with a comparatively lower data rate than the first modulation format.

6 . The method of claim 1 , where the first signal quality factor is a first bit error rate and the second signal quality factor is a second bit error rate, further comprising:
determining a differential bit error rate based on the first bit error rate and the second bit error rate; selectively causing the first modulation format to be changed to a third modulation format based on the differential bit error rate; and selectively causing the second modulation format to be changed to a fourth modulation format based on the differential bit error rate.

7 . The method of claim 1 , further comprising at least one of:
altering a transmission power of the first set of channels; performing forward error correction interleaving between the first set of channels and the second set of channels; adjusting a baud rate of the first set of channels; or adjusting a subcarrier usage of a channel of the first set of channels.

8 . The method of claim 1 , where transmitting the first set of channels further comprises:
transmitting the first set of channels to a passive power splitter,
the passive power splitter being associated with power-splitting the first set of channels to obtain power-split portions of the first set of channels and routing the power-split portions of the first set of channels to a set of wavelength selective switches,
the set of wavelength selective switches including the wavelength selective switch, and
the set of wavelength selective switches being associated with selectively routing received sets of channels toward one or more receivers.

9 . A system, comprising:
one or more optical devices configured to:
transmit a first channel using a first modulation format,
the first modulation format being selected based on a first bit error rate of a first optical signal associated with the first channel,
the first bit error rate being associated with attenuation of the first optical signal by one or more optical filters associated with one or more wavelength selective switches,
the first channel being included in a super-channel; and

transmit a second channel using a second modulation format,
the second transmission power being selected based on a second bit error rate of a second optical signal associated with the second channel,
the second bit error rate being associated with attenuation of the second optical signal by the one or more optical filters associated with the one or more wavelength selective switches,
the second channel being included in the super-channel.

10 . The system of claim 9 , where the first modulation format and the second modulation format are different.

11 . The system of claim 9 , where the first optical signal and the second optical signal are associated with different sets of wavelengths.

12 . The system of claim 9 , where the one or more optical devices, when transmitting the first channel, are further configured to:
transmit the first channel to a passive power splitter,
the passive power splitter being associated with generating a power-split portion of the first channel for routing to a particular wavelength selective switch of the one or more wavelength selective switches,
the particular wavelength selective switch being associated with selectively routing a portion of the power-split portion of the first channel toward a receiver.

13 . The system of claim 9 , where the one or more optical devices, when transmitting the first channel, are further configured to:
transmit the first channel toward a receiver using the first modulation format,
the first modulation format being selected at least in part based on a differential between the first bit error rate and the second bit error rate.

14 . The system of claim 9 , where the first modulation format is selected based on a data transfer rate associated with utilizing the first modulation format.

15 . The system of claim 9 , where the first modulation format is selected based a network performance score associated with utilizing the first modulation format.

16 . An apparatus, comprising:
one or more processors configured to:
determine a set of bit error rates associated with a corresponding set of channels associated with a set of optical signals,
a particular bit error rate, of the set of bit error rates, being associated with attenuation of an optical signal, of the set of optical signals, by a filter associated with a wavelength selective switch;

determine that the particular bit error rate, of the set of bit error rates, satisfies a threshold; and
cause a modulation format, selected for use when transmitting a particular channel of the set of channels, to be altered to another modulation format for use when transmitting the particular channel based on determining that the particular bit error rate, of the set of bit error rates, satisfies the threshold.

17 . The apparatus of claim 16 , where the one or more processors are further configured to:
monitor the particular channel to determine feedback information associated with the bit error rate; and where the one or more processors, when causing the modulation format to be altered, are further configured to:
cause the modulation format to be altered to the other modulation format based on the feedback information.

18 . The apparatus of claim 16 , where the one or more processors are further configured to:
determine a differential bit error rate associated with the particular channel and another channel; and determine that the particular bit error rate, of the set of bit error rates, satisfies the threshold

Assignees

• Infinera Corp

Inventors

• Mitchell Matthew L

Classifications

• H04B10/07953

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04Q2011/0009

  using wavelength filters · CPC title

• H04Q11/0005 Primary

  Switch and router aspects · CPC title

• H04B10/0793 Primary

  Network aspects, e.g. central monitoring of transmission parameters · CPC title

• H04J14/0212

  using optical switches or wavelength selective switches [WSS] · CPC title