Abstract: Described are, among other things, a method and a receiver for receiving a management data signal in an optical transmission system where a traffic data signal is transmitted as a NRZ modulated signal. The traffic data signal has a management data signal superimposed thereon as a pulse width modulation of the symbols of the NRZ modulated signal. The NRZ modulated signal is received with the data signal superimposed thereon and the traffic data signal is recovered. The recovered traffic data signal in anti-phase is added to the received signal. The management data signal is detected from the added signals.

Abstract: Described are, among other things, a method and a receiver for receiving a management data signal in an optical transmission system where a traffic data signal is transmitted as a NRZ modulated signal. The traffic data signal has a management data signal superimposed thereon as a pulse width modulation of the symbols of the NRZ modulated signal. The NRZ modulated signal is received with the data signal superimposed thereon and the traffic data signal is recovered. The recovered traffic data signal in anti-phase is added to the received signal. The management data signal is detected from the added signals.

Abstract: In a data transmission system, a first node receives at least two sets of input data signals including at least two signals being based on different synchronization sources. The first node extracts a respective clock signal representing the embedded clock signals from the sources, samples and formats these signals for transmission according to a TDM structure. The TDM formatted signals are transmitted as at least one bit stream over a transmission medium to at least one second node, where the bit stream is demultiplexed into at least two sets of output data signals respective demultiplexed clock signals representing the sampled clock signals. A jitter attenuating mechanism reduces an amount of frequency jitter to below a predefined level to produce a respective clock signal having a synchronization quality superior to that of the demultiplexed clock signals. An interface module recombines each data signal with its associated clock signal.

Abstract: A sampling unit (110) receives an input clock signal (CLKin) having a varying period time, and samples the input clock signal (CLKin) based on a sampling clock signal (CLKsmpl) that has a frequency being substantially higher than an average frequency of the input clock signal (CLKin). The sampling unit (110) produces a respective period length value (PL) for each period of the input clock signal (CLKin). An averaging unit (120) receives a number of period length values (PL) from the sampling unit (110), and based thereon produces an average period length value (PLavg) representing an average period time for the input clock signal (CLKin) over an averaging interval including a number of periods equivalent to said number of period length values (PL). An output unit (151) produces a stabilized output clock signal (CLKout) based on the average period length value (PLavg) and the sampling clock signal (CLKsmpl).

Abstract: In a data transmission system, a first node (100) receives at least two sets of input data signals (d-in1, d-in2) including at least two signals being based on different synchronization sources. The first node (100) extracts a respective clock signal (CLKex1, CLKex2) representing the embedded clock signals from said sources, samples and then formats these signals (CLKsp1, CLKsp2) for transmission according to a TDM structure. The TDM formatted signals are transmitted as at least one bit stream (bs1, bs2) over a transmission medium (L1, L2) to at least one second node (201, 202), where the bit stream (bs1, bs2) is demultiplexed into at least two sets of output data signals (d-out1, d-out2, d-out3, d-out4) respective demultiplexed clock signals (CLKdm1, CLKdm2) representing the sampled clock signals.

Abstract: A sampling unit (110) receives an input clock signal (CLKin) having a varying period time, and samples the input clock signal (CLKin) based on a sampling clock signal (CLKsmpl) that has a frequency being substantially higher than an average frequency of the input clock signal (CLKin). The sampling unit (110) produces a respective period length value (PL) for each period of the input clock signal (CLKin). An averaging unit (120) receives a number of period length values (PL) from the sampling unit (110), and based thereon produces an average period length value (PLavg) representing an average period time for the input clock signal (CLKin) over an averaging interval including a number of periods equivalent to said number of period length values (PL). An output unit (151) produces a stabilized output clock signal (CLKout) based on the average period length value (PLavg) and the sampling clock signal (CLKsmpl).

Abstract: The invention concerns an arrangement for supervising and/or controlling the bit rate of data pulses that are transmitted from a transmitter (16) to at least one optical conduction path (22). The transmitter (16) has an input side (18) which receives electrical pulses from an electric connection (14) and an output side (20) from which light pulses are transmitted in response to the received electrical pulses. The arrangement comprises a supervising unit (24) with at least one input (26) which is suited to be connected to said electric connection (14). The supervising unit (24) is arranged to estimate or determine the bit rate of the pulses that are received at said input (26). The arrangement is arranged to carry out at least one measure which depends on the estimated or determined bit rate.

Abstract: Device for controlling the current through a PN junction includes a voltage source connected in series to, in order, firstly a controllable current generator having an input connected to the voltage source, an output and a control input, thereafter a measurement resistor connected to the output, and finally a controlled output to which the PN junction is connected. The device further includes a control signal input, a differential amplifier and an integrating device, which includes a balanced integrator. The current through the output of the controllable current generator is proportional to the voltage difference between its input and its control input, and the reference voltage of the integrating device is constituted of the voltage of the voltage source.

Abstract: Device for controlling the current through a PN junction includes a voltage source connected in series to, in order, firstly a controllable current generator having an input connected to the voltage source, an output and a control input, thereafter a measurement resistor connected to the output, and finally a controlled output to which the PN junction is connected. The device further includes a control signal input, a differential amplifier and an integrating device, which includes a balanced integrator. The current through the output of the controllable current generator is proportional to the voltage difference between its input and its control input, and the reference voltage of the integrating device is constituted of the voltage of the voltage source.

Abstract: The present invention relates to a package of a polyolefin polymer, wherein it comprises an addition of a pro-oxidant in the form of at least one salt of a metal of the group consisting of Mn, Fe, Cu, Co, and Ni, whereby the polyolefin is provided with a filler in the form of a mineral, such as calcium carbonate, such as talc, crushed marble, chalk, including nano particles thereof, calcite, silica, and nano particle clays, a filler in the form of natural fiber such as cellulose fiber, wood fiber, powderous wood or china grass, rice spelt, and starch.

Abstract: The invention relates to a method for conveying management information in a WDM system from a number of wavelength converters to a central management unit, wherein a management information signal is superimposed on the WDM signal from the respective wavelength converter. A fraction of the optical signal in the common optical transmission line is tapped off to a detector and the different management information signals are recovered by a receiver unit which is connected to the detector. The invention also relates to a WDM system and a pluggable WDM wavelength converter.

Abstract: The invention concerns a transmitter circuit comprising a light source (20) and arranged to operate said light source (20) to transmit optical communication signals in response to balanced electric input signals from a first (11) and a second (12) circuit point. The transmitter circuit comprises a first (21) and a second (22) circuit branch which extend from said first (11) and second (12) points, respectively. The light source (20) is connected between the circuit branches (21, 22). The components which are positioned on the circuit branches (21, 22) are selected such that the transmitter circuit is formed with a symmetry which is such that, under normal operation conditions, a balanced drive voltage is the case between the connection points (13, 15) of the light source (20) on the circuit branches (21, 22) and such that the modulation current which drives the light source (20) essentially only depends on the voltage difference between said connection points (13, 15).

Abstract: The present invention relates to a package of a polyolefin polymer, wherein it comprises an addition of a pro-oxidant in the form of at least one salt of a metal of the group consisting of Mn, Fe, Cu, Co, and Ni, whereby the polyolefin is provided with a filler in the form of a mineral, such as calcium carbonate, such as talc, crushed marble, chalk, including nano particles thereof, calcite, silica, and nano particle clays, a filler in the form of natural fiber such as cellulose fiber, wood fiber, powderous wood or china grass, rice spelt, and starch.

Abstract: The invention concerns a transmitter-receiver device (A, B) which comprises a receiver unit (RXA) arranged to receive light and optical signals from a transmitter unit (TXA) arranged to transmit light and optical signals. The device also comprises a supervising unit (CUA) which prevents the transmitter unit (TXA) from continuously transmitting light when the supervising unit (CUA) detects that the receiver unit (RXA) does not receive light. The supervising unit (CUA) is arranged to, when it detects that the receiver unit (RXA) does not receive light, change to a test mode where the transmitter unit (TXA) is controlled to intermittently transmit short light pulses the supervising unit has an output (109) where a status signal indicates whether the transmitter-receiver device is in said test mode. The invention also concerns a communication system which comprising at least two such transmitter-receiver devices.

Abstract: The invention concerns a transmitter-receiver device (A, B) which comprises a receiver unit (RXA) for receiving optical signals and transmitter unit (TXA) for transmitting optical signals. Furthermore, the transmitter-receiver device (A, B) comprises a supervising unit (CUA) which supervises the functions of the receiver unit (RXA) and the transmitter unit (TXA). Furthermore, the transmitter-receiver device (A, B) comprises a transmitter circuit which transmits optical communication signals in response to a balanced electric input signal. The invention also concerns a communication system comprising two transmitter-receiver devices (A, B). Through the structure of the invention is by relatively simple means a well functioning device achieved, which, inter alia, makes it possible to supervise the status of the two transmitter-receiver devices (A, B) in an advantageous manner.

Abstract: The invention relates to a method for conveying management information in a WDM system from a number of wavelength converters to a central management unit, wherein a management information signal is superimposed on the WDM signal from the respective wavelength converter. A fraction of the optical signal in the common optical transmission line is tapped off to a detector and the different management information signals are recovered by a receiver unit which is connected to the detector. The invention also relates to a WDM system and a pluggable WDM wavelength converter.

Abstract: The invention concerns an amplifier circuit for receiving an optical signal. The circuit comprises a light sensitive member (301) which delivers an electric signal in response to an optical signal. Furthermore, the amplifier circuit comprises an amplifier unit (302) with a first input (304) which receives an electric signal from the light sensitive member (301). The amplifier unit (302) is of the kind which does not have any special input intended for controlling the amplification. A filter unit (310) prevents a possible direct current from the light sensitive member (301) from reaching the first input (304). A control unit (314) is connected to the first input (304) for controlling the amplification of the circuit. The invention also concerns an optical communication system comprising an amplifier circuit of the above-described kind. The invention also concerns a method of controlling the amplification in an optical input stage.

Abstract: The invention concerns an amplifier circuit which comprises an amplifier unit (210) arranged to receive an input signal, to influence the amplification of this input signal and to transmit an output signal. The amplifier circuit also comprises a first control unit (210) and a second control unit (220). Those control units receive said output signal. Furthermore, the amplifier circuit comprises a selector unit (240) which is arranged to receive first and second control signals from the control units (310, 220). The selector unit (240) is arranged to control the amplification of the amplifier unit (201) in accordance with that one of said first and second control signals which gives the lowest amplification.

Abstract: The invention concerns a transmitter-receiver device (A, B) which comprises a receiver unit (RXA) arranged to receive light and optical signals from a transmitter unit (TXA) arranged to transmit light and optical signals. The device also comprises a supervising unit (CUA) which prevents the transmitter unit (TXA) from continuously transmitting light when the supervising unit (CUA) detects that the receiver unit (RXA) does not receive light. The supervising unit (CUA) is arranged to, when it detects that the receiver unit (RXA) does not receive light, change to a test mode where the transmitter unit (TXA) is controlled to intermittently transmit short light pulses the supervising unit has an output (109) where a status signal indicates whether the transmitter-receiver device is in said test mode. The invention also concerns a communication system which comprising at least two such transmitter-receiver devices.

Abstract: The invention concerns an amplifier circuit for receiving an optical signal. The circuit comprises a light sensitive member (301) which delivers an electric signal in response to an optical signal. Furthermore, the amplifier circuit comprises an amplifier unit (302) with a first input (304) which receives an electric signal from the light sensitive member (301). The amplifier unit (302) is of the kind which does not have any special input intended for controlling the amplification. A filter unit (310) prevents a possible direct current from the light sensitive member (301) from reaching the first input (304). A control unit (314) is connected to the first input (304) for controlling the amplification of the circuit. The invention also concerns an optical communication system comprising an amplifier circuit of the above-described kind. The invention also concerns a method of controlling the amplification in an optical input stage.