Abstract: A transparent optical overlay network (1) for providing end-to-end optical spectrum services over multiple transparent optical network domains (2) is described. The transparent optical overlay network (1) includes network domain interface devices, NDIDs, (3) provided at domain boundaries between adjacent transparent optical network domains (2). The network domain interface device, NDID (3), monitors and adjusts incoming optical signals received by the NDID (3) from a first transparent optical network domain (2-1) and monitors and adjusts outgoing optical signals output by the NDID (3) to an adjacent second transparent optical network domain (2-2). An overlay network controller (5) manages and controls the end-to-end optical spectrum services by controlling the NDIDs (3). The overlay network controller collects telemetry data (TDATA) for optical spectrum service characterization and SLA policing of the optical spectrum services.

Abstract: An apparatus adapted to perform spectrometric measurements, said apparatus comprising a tunable laser light source adapted to generate a laser light with an excitation wavelength supplied to an optical sensor which produces a sample specific response light signal; an optical reference filter adapted to measure laser light with the excitation wavelength fed back as a reference signal to provide wavelength calibration of the tunable laser light source; at least one optical measurement filter adapted to measure the sample specific response light signal produced by the optical sensor, wherein the optical reference filter and the at least one optical measurement filter are thermally coupled to maintain a constant wavelength relationship between the filter characteristics of the optical filters.

Abstract: An apparatus adapted to perform spectrometric measurements, said apparatus comprising a tunable laser light source adapted to generate a laser light with an excitation wavelength supplied to an optical sensor which produces a sample specific response light signal; an optical reference filter adapted to measure laser light with the excitation wavelength fed back as a reference signal to provide wavelength calibration of the tunable laser light source; at least one optical measurement filter adapted to measure the sample specific response light signal produced by the optical sensor, wherein the optical reference filter and the at least one optical measurement filter are thermally coupled to maintain a constant wavelength relationship between the filter characteristics of the optical filters.

Abstract: A life cycle network management system for performing life cycle management of distributed network devices, each network device comprising a communication link to a central network management unit and an attached transponder configured to store life cycle data of the network device updated by said network device, wherein if the communication link between the network device and the central network management unit is at least temporarily unavailable the updated life cycle data of the network device stored in the attached transponder is read by an interrogation unit of the life cycle network management system and processed to provide a life cycle management result.

Abstract: A life cycle network management system for performing life cycle management of distributed network devices, each network device comprising a communication link to a central network management unit and an attached transponder configured to store life cycle data of the network device updated by said network device, wherein if the communication link between the network device and the central network management unit is at least temporarily unavailable the updated life cycle data of the network device stored in the attached transponder is read by an interrogation unit of the life cycle network management system and processed to provide a life cycle management result.

Abstract: Disclosed is an optical coupler device, especially for monitoring purposes in an optical point-to-point transmission link, which includes a first, a second and a third optical port and is configured to transmit a first optical signal received at the first optical port to the second optical port and to transmit a second optical signal received at the second optical port to the first and third optical port according to a monitoring split ratio with respect to the optical power of the second optical signal, the first and second optical signal having a wavelength lying in a first optical band. The device is further configured to transmit a third and a fourth optical signal received at the third and the second optical port to the respective other optical port, the third and fourth optical signal having a wavelength lying in a second optical band. The device is controllable with respect to the monitoring split ratio and includes a control means adapted to receive a control signal.

Abstract: An apparatus and method for providing a differential latency, DL, between an upstream, US, transmission and a downstream, DS, transmission via an optical transmission link (OTL), said apparatus comprising a measurement unit (2) configured to measure the round trip delays, RTD, of at least two measurement signals having different measurement wavelengths; and a processing unit (3) configured to derive an upstream, US, delay of at least one optical signal at an upstream wavelength from the at least two measured round trip delays, RTD, and to derive a downstream, DS, delay of at least one optical signal at a downstream wavelength from the at least two measured round trip delays, RTD, wherein the differential latency, DL, is calculated on the basis of the derived delays, RTD.

Abstract: The invention relates to an optical WDM transmission network including at least one optical line terminal, a remote node and a plurality of optical network units. The at least one optical line terminal is connected to the optical remote node via an optical WDM path. Each optical network unit is connected to the optical remote node via an optical distribution path.

Abstract: The invention relates to an optical communication network (1) comprising a plurality of nodes (2) connected to each other by means of optical fibers (3) in a ring structure, wherein optical signals are transported at working wavelengths (?w) in a first direction in said ring structure and wherein optical signals are transported at protection wavelengths (?p) in a second direction that is opposite to the first direction in said ring structure, wherein for each node (2) at least one wavelength assignment table (WAT) is provided, wherein to each working wavelength (?w) a corresponding protection wavelength (?p) is assigned, wherein in case of a detected connection failure in said ring structure each node (2) which loses at least one connection performs for all working wavelengths (?w) affected by said connection failure a lookup in its wavelength assignment table (WAT) to determine the respective protection wavelength (?p) and tunes lasers of transceiver units to the determined protection wavelengths (?p).

Abstract: The invention relates to an optical WDM transmission network including at least one optical line terminal, a remote node and a plurality of optical network units. The at least one optical line terminal is connected to the optical remote node via an optical WDM path. Each optical network unit is connected to the optical remote node via an optical distribution path.

Abstract: A method for tuning a tunable optical transmitter to a target wavelength includes applying at least one tuning signal to the tunable optical transmitter to control the tunable optical transmitter to create an optical calibration signal according to nominal tuning information for the tunable optical transmitter. The optical calibration signal has a wavelength lying within a secure wavelength range, and the nominal tuning information is based on a nominal wavelength dependency for the tunable optical transmitter. The method also includes measuring a deviation between an actual wavelength dependency of the tunable optical transmitter and the nominal wavelength dependency, and determining calibration information based on that deviation. The calibration information is applied to determine a corrected nominal wavelength dependency from which target tuning information is determined. The tunable optical transmitter is controlled to create an optical channel signal according to the target tuning information.

Abstract: A first and second head-end terminal and at least one optical add/drop filter device are connected to form a transmission path. Each head-end terminal is connected through an optical fiber to a western or eastern WDM port of an adjacent optical add/drop filter device, and each optical add/drop filter device is connected, at an eastern or western WDM port, to a western or eastern WDM port of an adjacent optical add/drop filter device. At least one tail-end terminal is connected to each optical add/drop filter device, wherein a first and second channel port of the respective add/drop tail-end terminal is connected to a dedicated first and second channel port of the optical add/drop filter device through a respective optical fiber. The head-end terminals, the optical add/drop filter devices, and the tail-end terminals are adapted to establish bidirectional communication between each tail-end terminal and the first and second head-end terminal.

Abstract: An apparatus and method for providing a differential latency, DL, between an upstream, US, transmission and a downstream, DS, transmission via an optical transmission link (OTL), said apparatus comprising a measurement unit (2) configured to measure the round trip delays, RTD, of at least two measurement signals having different measurement wavelengths; and a processing unit (3) configured to derive an upstream, US, delay of at least one optical signal at an upstream wavelength from the at least two measured round trip delays, RTD, and to derive a downstream, DS, delay of at least one optical signal at a downstream wavelength from the at least two measured round trip delays, RTD, wherein the differential latency, DL, is calculated on the basis of the derived delays, RTD.

Abstract: The invention relates to a method of operating a first optical network element (100), particularly an optical network unit, ONU, wherein said method comprises the following steps: performing a coarse tuning process (2100) of at least one transmission wavelength which is used by said first optical network element (100) for transmitting an optical signal to a second optical network element (200), particularly an optical line terminal, OLT, and performing a fine tuning process (2200) of said at least one transmission wavelength, wherein said fine tuning process (2200) is preferably performed after said coarse tuning process (2100).

Abstract: A method for bi-directionally transmitting digital optical signals over an optical transmission link in which a first optical transmit signal is created according to a first binary digital signal in such a way that the bit information of the first binary digital signal is included in first sections of the symbol interval of the first optical transmit signal. A second optical transmit signal is created by creating an optical wavelength reuse signal using the first optical transmit signal received at the second end of the optical transmission link, the optical wavelength reuse signal being modulated according to a second digital signal in such a way that the bit information of the second digital signal is included in second sections of the symbol interval of the first optical transmit signal received.

Abstract: An optical transmission system method including generating for a tunable laser a pilot tone having an adjustable pilot tone frequency identifying a wavelength division multiplexing channel used by the tunable laser; multiplying the pilot tone with pilot tone data to provide a pilot tone data signal; supplying the pilot tone data signal and a high frequency data signal to the tunable laser generating an optical laser signal output by the tunable laser responsive to the supplied signals; transporting the optical laser signal to a central wavelength to locker; converting the received optical laser signal to provide a pilot tone data signal for wavelength division multiplexing channels demodulated to detect the pilot tone and the pilot tone data for each individual wavelength division multiplexing channel; and identifying the wavelength division multiplexing channel on the basis of the pilot tone frequency of the detected pilot tone and evaluating the pilot tone data.

Abstract: Disclosed is an optical coupler device, especially for monitoring purposes in an optical point-to-point transmission link, which includes a first, a second and a third optical port and is configured to transmit a first optical signal received at the first optical port to the second optical port and to transmit a second optical signal received at the second optical port to the first and third optical port according to a monitoring split ratio with respect to the optical power of the second optical signal, the first and second optical signal having a wavelength lying in a first optical band. The device is further configured to transmit a third and a fourth optical signal received at the third and the second optical port to the respective other optical port, the third and fourth optical signal having a wavelength lying in a second optical band. The device is controllable with respect to the monitoring split ratio and includes a control means adapted to receive a control signal.

Abstract: The invention relates to a method of operating a primary optical node, particularly an optical line terminal (OLT), for an optical communications system, wherein said OLT is configured to receive at least one upstream optical signal (uos) from at least one secondary optical node, particularly an optical networking unit (ONU), within at least a first wavelength range (wr1), and to transmit at least one downstream optical signal (dos) to said at least one ONU within at least a second wavelength range (wr2), wherein said OLT determines a currently unused wavelength subrange (wsr2) within said first wavelength range (wr1), assigns a specific target wavelength (?t) within said currently unused wavelength subrange (wsr2) to said ONU, signals said target wavelength (?t) to said ONU, receives an upstream signal (us) from said ONU, and provides feedback information to said ONU.

Abstract: A method for tuning a tunable optical transmitter to a target wavelength includes applying at least one tuning signal to the tunable optical transmitter to control the tunable optical transmitter to create an optical calibration signal according to nominal tuning information for the tunable optical transmitter. The optical calibration signal has a wavelength lying within a secure wavelength range, and the nominal tuning information is based on a nominal wavelength dependency for the tunable optical transmitter. The method also includes measuring a deviation between an actual wavelength dependency of the tunable optical transmitter and the nominal wavelength dependency, and determining calibration information based on that deviation. The calibration information is applied to determine a corrected nominal wavelength dependency from which target tuning information is determined. The tunable optical transmitter is controlled to create an optical channel signal according to the target tuning information.

Abstract: The invention relates to an optical network element, particularly an optical line terminal, OLT, for transmitting and receiving signals wire an optical network that comprises at least one optical fiber link and at least one further optical network element. The optical network element provides a primary optical pumping mean for emitting optical pump power to set at least one optical fiber link. The emitted optical pump power forms at least one gain medium outside the optical network element to provide optical pump power to the network for amplifying the singles to receive so that outside of the domain of the optical network element no electrical energy supply is needed.