Abstract: An apparatus and method for mitigating wavelength drift in an optical communication network. A network node such as an OLT in a PON receives a transmission on a certain optical channel. The received signal is of course sent to a receive module for processing the data contained therein, and may be sent to an RSSI module for signal strength analysis. A portion of the received transmission, however, is directed to a wavelength control section where it is divided into at least a first path and a second path, the second path having a wavelength discriminator filter. The light propagating along each path is converted to an electrical signal and digitized for comparison by a microcontroller. The microcontroller calculates one or more power ratios and from this determines the receive signal wavelength. This wavelength is compared to the wavelength of a selected channel to determine what if any adjustments should be made.

Abstract: An apparatus and method for mitigating wavelength drift in an optical communication network. A network node such as an OLT in a PON receives a transmission on a certain optical channel. The received signal is of course sent to a receive module for processing the data contained therein, and may be sent to an RSSI module for signal strength analysis. A portion of the received transmission, however, is directed to a wavelength control section where it is divided into at least a first path and a second path, the second path having a wavelength discriminator filter. The light propagating along each path is converted to an electrical signal and digitized for comparison by a microcontroller. The microcontroller calculates one or more power ratios and from this determines the receive signal wavelength. This wavelength is compared to the wavelength of a selected channel to determine what if any adjustments should be made.

Abstract: An apparatus and method for transmitting in an optical communication network. Optical transmissions, and in particular burst mode transmissions, are subject to wavelength drift. Described herein is a manner of executing optical transmissions while mitigating wavelength drift, in some cases without significantly reducing transmit power. Emphasis is placed on timely and efficient feedback so that adjustments may be made. A network node such as an ONT in a PON is provided with a light source and means for modulating an upstream optical transmission. A tap provides a portion of the generated (and perhaps modulated) light beam to a wavelength control loop, which in a preferred embodiment includes a channel selection filter and a wavelength discrimination filter. The wavelength generated by the light source is adjusted, if necessary, according to, at least in part, the output of the wavelength control loop.

Abstract: Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).

Abstract: Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).

Abstract: Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).

Abstract: Disabling data channels at a customer premises provides, in one embodiment, generating at least one jamming signal and inserting the at least one jamming signal at a first frequency to jam at least one carrier frequency channel. The jamming signal may be hopped to at least one additional frequency different from the first frequency to jam at least one additional carrier frequency channel.

Abstract: An amplifier circuit in a PON and a method for using the same. The amplifier circuit may be used, for example in an ONU of the PON. In order to deal with varying customer requirements and the possibility of the ONUs or similar devices being installed at varying distances from the CO, a dynamically adjustable amplifier bias voltage is determined and applied to at least one amplifier in the amplifier circuit. The dynamic bias voltage is preferably a function of the input power to the ONU or the circuit output quality, or both. More than one dynamic bias voltage may be determined and applied in this fashion.

Abstract: Disclosed are an apparatus and method configured to process video data signals operating on a passive optical network (PON). One example method of operation may include receiving a data signal at an optical distribution network node (ODN) and identifying signal interference in the data signal. The method may also include modifying a shape of the data signal in the electrical domain and transmitting the modified data signal to at least one optical termination unit (ONT).

Abstract: A system, method, and computer readable medium for increasing an upstream optical coding gain in a passive optical network (PON). In an exemplary embodiment of the invention, the system may include a memory structured to store Optical Network Terminator (ONT) burst timing values, and provide a previous burst timing value of the burst timing values to a translator. Further, an upstream burst grant timing scheduler may provide a scheduled timing value to the translator, wherein the translator may be structured to translate the previous burst timing value to a new expected timing value per an ONT upstream burst in association with the scheduled timing value. Also, a delimiter match and search block may be structured to use the new expected timing value to check a bit stream for a delimiter pattern match. An alarm counter may be provided in the system that is structured to provide an alarm when the delimiter pattern match is not found.

Abstract: Disabling data channels at a customer premises provides, in one embodiment, generating at least one jamming signal and inserting the at least one jamming signal at a first frequency to jam at least one carrier frequency channel. The jamming signal may be hopped to at least one additional frequency different from the first frequency to jam at least one additional carrier frequency channel.

Abstract: An xDSL modem having an adaptive hybrid termination impedance. The modem has a transformer with two cores, one connected to the modem's receiver and the other connected to the modem's transmitter. The two cores share an adjustable termination impedance. The modem determines which impedance setting to use, based on one or more measurements of channel loss, local echo power and received power from the far end transmitter, and the like.

Abstract: A system, method, and computer readable medium for increasing an upstream optical coding gain in a passive optical network (PON). In an exemplary embodiment of the invention, the system may include a memory structured to store Optical Network Terminator (ONT) burst timing values, and provide a previous burst timing value of the burst timing values to a translator. Further, an upstream burst grant timing scheduler may provide a scheduled timing value to the translator, wherein the translator may be structured to translate the previous burst timing value to a new expected timing value per an ONT upstream burst in association with the scheduled timing value. Also, a delimiter match and search block may be structured to use the new expected timing value to check a bit stream for a delimiter pattern match. An alarm counter may be provided in the system that is structured to provide an alarm when the delimiter pattern match is not found.

Abstract: An xDSL modem having an adaptively adjustable guard band comprising a finite number of spaced-apart frequency bins between the upstream and downstream frequencies. The guard band is adjusted by selecting one from among a plurality of filters belonging to a filter bank of the receiver circuitry. A weighted loss in data capacity is calculated when each of the candidate filters are used, and the filter which gives the lowest loss in data capacity, subject to certain criteria, is used. The adjustment is made pursuant to noise and signal characteristics measured during start or restart of an xDSL communications session.

Abstract: Constant light output is provided by a laser diode over various temperatures or operating points by adjusting the bias current in accordance with a midpoint of a detected peak and a detected valley of an output power level and adjusting the modulation current amplitude in accordance with the difference between the detected peak and the detected valley output power.

Abstract: The apparatus (10) includes a laser driver (16) that receives low speed and high speed digital and analog input signals (12, 14), and biases and modulates the laser diode (22) accordingly. The laser driver (16) receives and responds to input from a feedback circuit (36, 38), which includes an average power control portion (36), and a modulation power control portion (38). The average power control portion (36) of the feedback circuit generally determines the DC component of the laser diode output, and compares it to a reference average. The modulation power control portion (38) of the feedback circuit generally determines the maximum and minimum peaks in the laser diode output, takes their average and compares the average to the DC component of the laser output from the average power control portion (36). The laser diode (22) is then driven by the laser driver (16) in response to the comparisons.

Abstract: Constant light output is provided by a laser diode over various temperatures or operating points by adjusting the bias current in accordance with a midpoint of a detected peak and a detected valley of an output power level and adjusting the modulation current amplitude in accordance with the difference between the detected peak and the detected valley output power.