# US 2014/0193148 A1 · Node and Method For Iterative Improvement of Spectral Use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193148 A1 - Document ID: US20140193148A1 - Status: Published application - Kind: A1 - Application number: 13/819,927 - Filed: 2012-06-15 - Published: 2014-07-10 - Earliest claimed: 2012-05-10 - Assignees: Telefonaktiebolaget I.M. Ericsson (publ) - Inventors: Stefan Dahlfort; Gianmarco Bruno; Daniele Ceccarelli; Antonio Tartaglia; Ming Xia - Web page: https://patentgrep.com/patent/US20140193148A1 ## CPC - H04B 10/073: using an out-of-service signal (H04B10/071 takes precedence) - H04B 10/0775: {Performance monitoring and measurement of transmission parameters} - H04B 10/27: Arrangements for networking - H04B: TRANSMISSION ## Abstract Example embodiments presented herein are directed towards an optical testing node, and method therein, for establishing transmission parameters for optical communications in an iterative manner. The establishment of the transmission parameters may comprise adjusting various parameters such as a modulation scheme, a light path length, and/or a spectral width. ## Claims ### Claim 1 A method, in an optical testing node, for establishing transmission parameters for optical communications, the method comprising: transmitting an optical test signal through an optical network; analysing results of the transmitted optical test signal; and adjusting at least one parameter of said optical test signal based on the analysing, wherein said transmitting, analysing and adjusting are performed in an iterative manner. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one parameter is a current modulation scheme, a current light path length, and/or a current spectral width of the optical test signal. ### Claim 3 (depends on 1) The method of claim 1, wherein the transmitting further comprising transmitting the optical test signal according to a routing wavelength assignment or a routing spectrum assignment. ### Claim 4 (depends on 2) The method of claim 2, wherein upon analysing the results, if the transmitted optical test signal is not detected due to a lack of spectral width, the adjusting further comprises: selecting a new modulation scheme, from a sub-set of modulation schemes, such that the new modulation scheme has a higher spectral efficiency than the current modulation scheme; and thereafter, assigning the new modulation scheme as the current modulation scheme. ### Claim 5 (depends on 2) The method of claim 2, wherein upon analysing the results, if the transmitted optical test signal is not detected due to a low optical signal to noise ratio, the adjusting further comprises: increasing the current light path length; selecting a new modulation scheme, from a sub-set of modulation schemes, such that the new modulation scheme comprises a least amount of spectral efficiency from the sub-set of modulation schemes; and thereafter, assigning the new modulation scheme as the current modulation scheme. ### Claim 6 (depends on 2) The method of claim 2, wherein upon analysing the results, if the optical test signal is detected signal, the adjusting further comprises decreasing the current spectral width of the optical test signal. ### Claim 7 (depends on 2) The method of claim 2, wherein the adjusting further comprises: simultaneously adjusting the current modulation scheme and the current light path length; and determining an optimal modulation scheme and optimal light path length, wherein when the optical test signal is detected, the current modulation scheme and the current light path length equal the optimal modulation scheme and optimal light path length, respectively. ### Claim 8 (depends on 7) The method of claim 7, wherein upon determining the optimal modulation scheme and the optimal light path length, the adjusting further comprises: adjusting the current spectral width; and determining an optimal light path length, such that when the optical test signal is not detected, the optimal spectral width is a next highest spectral width, from a sub-set of spectral widths, compared to the current spectral width. ### Claim 9 (depends on 4) The method of claim 4, wherein the sub-set of modulation schemes comprises at least one of a binary phase-shift keying, a dual polarization binary phase-shift keying, a dual polarization quadrature phase-shift keying, and/or a dual polarization 16 quadrature amplitude modulation. ### Claim 10 An optical testing node for establishing transmission parameters for optical communications, the optical testing node comprising: transmitting circuitry configured to transmit an optical test signal through an optical network; processing circuitry configured to analyse results of the transmitted optical test signal; and the processing circuitry further configured to adjust at least one parameter of said optical test signal based on the analysing, wherein said transmitting and processing circuitry are configured to operate in an iterative manner. ### Claim 11 (depends on 10) The optical testing node of claim 10, wherein the at least one parameter is a current modulation scheme, a current light path length, and/or a current spectral width of the optical test signal. ### Claim 12 (depends on 10) The optical testing node of claim 10, wherein the transmitting circuitry is configured to transmit the optical testing signal according a routing wavelength assignment or a routing spectrum assignment. ### Claim 13 (depends on 11) The optical testing node of claim 11, wherein upon analysing the results, if the transmitted optical test signal is not detected due to a lack of spectral width, the processing circuitry is further configured select a new modulation scheme, from a sub-set of modulation schemes, such that the new modulation scheme has a higher spectral efficiency than the current modulation scheme; and thereafter, the processing circuitry is also configured to assign the new modulation scheme as the current modulation scheme. ### Claim 14 (depends on 11) The optical testing node of claim 11, wherein upon analysing the results, if the transmitted optical test signal is not detected due to a low optical signal to noise ratio, the processing circuitry is further configured to increase the current light path length, the processing circuitry is also configured to select a new modulation scheme, from a sub-set of modulation schemes, such that the new modulation scheme comprises a least amount of spectral efficiency from the sub-set of modulation schemes; and thereafter the processing circuitry is further configured to assign the new modulation scheme as the current modulation scheme. ### Claim 15 (depends on 11) The optical testing node of claim 11, wherein upon analysing the results, if the optical test signal is detected signal, the processing circuitry is further configured to decrease the current spectral width of the optical test signal. ### Claim 16 (depends on 11) The optical testing node of claim 11, wherein the processing circuitry is further configured to simultaneously adjust the current modulation scheme and the current light path length, and the processing circuitry is also configured to determine an optimal modulation scheme and optimal light path length, wherein when the optical test signal is detected, the current modulation scheme and the current light path length equal the optimal modulation scheme and optimal light path length, respectively. ### Claim 17 (depends on 16) The optical testing node of claim 16, wherein upon determining the optimal modulation scheme and the optimal light path length, the processing circuitry is further configured to adjust the current spectral width, and the processing circuitry is also configured to determine an optimal light path length, such that when the optical test signal is not detected, the optimal spectral width is a next highest spectral width, from a sub-set of spectral widths, compared to the current spectral width. ### Claim 18 (depends on 11) The optical testing node of claim 11, wherein the sub-set of modulation scheme comprises at least one of a binary phase-shift keying, a dual polarization binary phase-shift keying, a dual polarization quadrature phase-shift keying, and/or a dual polarization 16 quadrature amplitude modulation.