Abstract: Transmitting and receiving apparatuses, transmitting and receiving methods, and a transceiver for a phased array antenna are provided. The transmitting apparatus may comprise a laser light source configured to provide an optical beam comprising one or more spectral components. The transmitting apparatus may comprise a modulator configured to modulate the optical beam with a signal to be transmitted. The transmitting apparatus may comprise one or more group delay controlling units configured to add one or more controllable time delays to the one or more spectral components. Further, the transmitting apparatus may comprise a plurality of waveguides each having a chromatic dispersion configured to guide the optical beam, wherein the laser light source is tunable to control time delays added by the plurality of waveguides.

Abstract: A method in a transceiver apparatus for monitoring an optical link over which one or more data signals are to be transmitted comprises time interleaving a test signal with an auxiliary management and control channel, AMCC, signal to form a time-interleaved signal. The time-interleaved signal is transmitted with one or more downstream data signals over the optical link. A backscattered test signal is received to monitor the optical link.

Abstract: A method in a transceiver apparatus for monitoring an optical link over which one or more data signals are to be transmitted comprises time interleaving a test signal with an auxiliary management and control channel, AMCC, signal to form a time-interleaved signal. The time-interleaved signal is transmitted with one or more downstream data signals over the optical link. A backscattered test signal is received to monitor the optical link.

Abstract: A method in a first network node for determining a latency of a transmission link between the first network node and a second network node in a communications network. The first network node transmits an electromagnetic signal to the second network node over the transmission link as a first Frequency-Division Multiplexed (FDM) signal comprised in a first electromagnetic carrier also comprising payload data. The first network node receives the electromagnetic signal from the second network node over the transmission link, wherein the electromagnetic signal has been transmitted from the second network node as a second FDM signal comprised in a second electromagnetic carrier also comprising payload data. The first network node determines the latency of the transmission link based on a phase difference between the transmitted electromagnetic signal and the received electromagnetic signal.

Abstract: Transmitting and receiving apparatuses, transmitting and receiving methods, and a transceiver for a phased array antenna are provided. The transmitting apparatus may comprise a laser light source configured to provide an optical beam comprising one or more spectral components. The transmitting apparatus may comprise a modulator configured to modulate the optical beam with a signal to be transmitted. The transmitting apparatus may comprise one or more group delay controlling units configured to add one or more controllable time delays to the one or more spectral components. Further, the transmitting apparatus may comprise a plurality of waveguides each having a chromatic dispersion configured to guide the optical beam, wherein the laser light source is tunable to control time delays added by the plurality of waveguides.

Abstract: An optical receiver (10) comprising: an input (12) arranged to receive a subcarrier multiplexing, SCM, optical signal (14) comprising an optical carrier and an optical subcarrier, each having a respective optical power; a carrier suppression element, CSE, (16) arranged to receive the SCM optical signal and having a rejection band that is tunable in frequency to partially suppress the optical carrier by a variable amount; an optical amplifier (18) having a variable gain and arranged to receive the SCM optical signal from the CSE and amplify the optical carrier and the optical subcarrier; a photoreceiver (20) arranged to receive the SCM optical signal from the amplifier; and a controller (24) arranged to cause frequency tuning of the rejection band and variation of the gain of the optical amplifier to adjust a ratio of the optical power of the optical carrier at the photoreceiver to the optical power of the optical subcarrier at the photoreceiver based on an indication of performance of the SCM optical signal.

Abstract: Embodiments herein relate to a method in a network unit for monitoring a fiber line between a radio base station and a radio head in a Fiber to the Radio Head communications network. The Fiber to the Radio Head communications network comprises a ring architecture or a tree architecture of fiber, with Subcarrier Multiplexing, SCM, downstream transmissions and Wavelength Division Multiplexing, WDM, upstream transmissions. The monitoring comprises that the network unit detects an indication of a fault along the fiber line based on monitoring power. The network unit initiates, in response to detect the indication, an Optical×Domain Reflectometry, O×DR, measurement over the fiber line. Additionally, the network unit analyses a trace from the O×DR measurement for localizing the fault or for deciding that the indicated fault is not a fault along the fiber line.

Abstract: A method in an arrangement for monitoring a transmission line to a radio device in a communication network, wherein the transmission line comprises an optical part carrying signals in an optical domain and an electrical part carrying analog information signals in an electrical domain. The arrangement selects a carrier in the electrical part for monitoring the transmission line by assigning a test signal to a subcarrier out of a number of subcarriers of an optical carrier, wherein the subcarrier in the optical domain corresponds to the selected carrier in the electrical domain. Furthermore, the arrangement monitors the transmission line by analyzing a signal, associated with the test signal, received over the assigned subcarrier or another subcarrier.

Abstract: An optical receiver (10) comprising: an input (12) arranged to receive a subcarrier multiplexing, SCM, optical signal (14) comprising an optical carrier and an optical subcarrier, each having a respective optical power; a carrier suppression element, CSE, (16) arranged to receive the SCM optical signal and having a rejection band that is tuneable in frequency to partially suppress the optical carrier by a variable amount; an optical amplifier (18) having a variable gain and arranged to receive the SCM optical signal from the CSE and amplify the optical carrier and the optical subcarrier; a photoreceiver (20) arranged to receive the SCM optical signal from the amplifier; and a controller (24) arranged to cause frequency tuning of the rejection band and variation of the gain of the optical amplifier to adjust a ratio of the optical power of the optical carrier at the photoreceiver to the optical power of the optical subcarrier at the photoreceiver based on an indication of performance of the SCM optical signal.

Abstract: A first transceiver and a method performed by the first transceiver for monitoring a fiber cable. The first transceiver is connectable to a second transceiver by the fiber cable. The transceivers employ SCM analog modulation where baseband is dedicated for monitoring and the subcarriers are dedicated for data transmission. The method comprises receiving, from a device, at least one electromagnetic data signal to be transmitted towards the second transceiver on the fiber cable, and shifting the at least one data signal in the frequency domain. The method further comprises generating an electromagnetic test signal in a base band, combining the at least one data signal and the generated test signal, and modulating the combined data signal and test signal to respective optical carrier. The method further comprises transmitting the modulated data signal and generated test signal on the fiber cable towards the second transceiver.

Abstract: An optical device comprising, an optical input and output device comprising a first input port, a second input port, a first output port and a second output port, and an optical filtering device comprising an input port coupled to the first output port and an output port coupled to the second input port, and an optical amplifying device comprising an input port coupled to the second output port. The optical input and output device is adapted to couple the output port comprised in the optical filtering device to the input port comprised in the optical amplifying device. The optical filtering device comprises a multiple of cascaded phase shifted Bragg gratings, each being adapted to filter an associated respective optical carrier within to produce a respective output signal to the optical amplifying device.

Abstract: An ONT and a method therein for maintenance and administration of the ONT are provided. The ONT is comprised in an Optical Distribution Network, ODN. The method comprises connecting 210 an OLT in the ODN to a maintenance unit comprised in the ONT when a first signal is received from the OLT instructing the ONT to enter a maintenance mode. The method comprises updating 220 existing maintenance and administration information in the maintenance unit, the maintenance and administration information relating to the operation of the ONT when receiving new maintenance and administration information from the OLT. The method comprises connecting 230 the OLT to a host which host is connected to the ONT when receiving, from the OLT, a second signal instructing the ONT to enter an operation mode, or after a predetermined period of time; and operating 240 the ONT in accordance with the updated maintenance and administration information in the maintenance unit.

Abstract: A Wavelength Adaptation Module and a method therein for adapting an Optical Time Domain Reflectometry, OTDR, signal for supervision of Optical Network Terminals, ONTs, in a Passive Optical Network, PON, are provided. The wavelength of the OTDR signal is adapted to have a selected wavelength to enable a splitter in a remote node to forward the OTDR signal to a dedicated group of ONTs in the PON, thereby supervising the fiber links between the remote node and the dedicated group of ONTs. Likewise, a remote node and a method therein for receiving an OTDR signal having a pre-selected wavelength from the Wavelength Adaptation Module and for outputting the OTDR signal to a dedicated group of ONTs with regards to the pre-selected wavelength of the received OTDR signal are provided.

Abstract: An optical device comprising, an optical input and output device comprising a first input port, a second input port, a first output port and a second output port, and an optical filtering device comprising an input port coupled to the first output port and an output port coupled to the second input port, and an optical amplifying device comprising an input port coupled to the second output port. The optical input and output device is adapted to couple the output port comprised in the optical filtering device to the input port comprised in the optical amplifying device. The optical filtering device comprises a multiple of cascaded phase shifted Bragg gratings, each being adapted to filter an associated respective optical carrier within to produce a respective output signal to the optical amplifying device.

Abstract: A first transceiver and a method performed by the first transceiver for monitoring a fibre cable. The first transceiver is connectable to a second transceiver by the fibre cable. The transceivers employ SCM analogue modulation where baseband is dedicated for monitoring and the subcarriers are dedicated for data transmission. The method comprises receiving, from a device, at least one electromagnetic data signal to be transmitted towards the second transceiver on the fibre cable, and shifting the at least one data signal in the frequency domain. The method further comprises generating an electromagnetic test signal in a base band, combining the at least one data signal and the generated test signal, and modulating the combined data signal and test signal to respective optical carrier. The method further comprises transmitting the modulated data signal and generated test signal on the fibre cable towards the second transceiver.

Abstract: A Passive Optical Network, PON, comprising an Optical Line Termination, OLT, connected to one or more Optical Network Terminals, ONT, over an Optical Distribution Network, ODN, is monitored by a monitoring device. The monitoring device comprises an Optical Frequency Domain Reflectometer, OFDR, and is arranged to monitor the optical power received by the OLT and the ONTs of the PON, and to perform transceiver analysis of the OLT and the ONTs, combined with an OFDR analysis of the ODN, based on the monitored optical power violating a threshold.

Abstract: A method in a first network node for determining a latency of a transmission link between the first network node and a second network node in a communications network. The first network node transmits an electromagnetic signal to the second network node over the transmission link as a first Frequency-Division Multiplexed FDMLsignal comprised in a first electromagnetic carrier also comprising payload data. The first network node receives the electromagnetic signal from the second network node over the transmission link, wherein the electromagnetic signal has been transmitted from the second network node as a second FDM signal comprised in a second electromagnetic carrier also comprising payload data. The first network node determines the latency of the transmission link based on a phase difference between the transmitted electromagnetic signal and the received electromagnetic signal.

Abstract: It is disclosed a remote node connectable to multiple feeder fibers from one or more central offices, COs, of a wavelength division multiplexing-based passive optical network, WDM-based PON. The remote node comprises one or more splitters each configured to receive a monitoring signal on a connected feeder fiber and to split the monitoring signal into split monitoring signals, wherein the monitoring signal uses one wavelength at a time out of a group of different wavelengths, and an arrayed waveguide grating, AWG, with output ports connectable to drop fibers. The AWG is configured to route the split monitoring signals to output ports of said AWG based on a currently used wavelength of said group of different wavelengths, for supervising drop fibers connected to the output ports. Also, a method for a remote node in the WDM-based PON, of routing a monitoring signal, is disclosed.

Abstract: A remote node in a passive optical network (PON), the remote node comprises a filter arrangement and a sequential splitter arrangement, where the filter arrangement is arranged to receive a feeder signal including data communication content and optical time domain reflectometry (OTDR) pulses, and where the filter arrangement is adapted to transmit the data communication content to the sequential splitter arrangement. Furthermore, the invention involves a method for determining the location of a fault section in a drop section.

Abstract: A method in an arrangement for monitoring a transmission line to a radio device in a communication network, wherein the transmission line comprises an optical part carrying signals in an optical domain and an electrical part carrying analogue information signals in an electrical domain. The arrangement selects a carrier in the electrical part for monitoring the transmission line by assigning a test signal to a subcarrier out of a number of subcarriers of an optical carrier, wherein the subcarrier in the optical domain corresponds to the selected carrier in the electrical domain. Furthermore, the arrangement monitors the transmission line by analysing a signal, associated with the test signal, received over the assigned subcarrier or another subcarrier.