An apparatus for automatic amplifier gain setting of an optical amplifier, said apparatus comprising an optical channel counter, OCC, unit configured to detect a number of channels present in an optical transmission spectrum; a determination unit configured to determine an average power per channel calculated by dividing a measured total power of a signal input and/or signal output of the optical amplifier by the number of channels detected by said optical channel counter, OCC, unit and a gain adjustment unit configured to adjust the amplifier gain of said optical amplifier automatically depending on a calculated power difference between a predetermined desired power per channel and the determined average power per channel provided by said determination unit.

A high speed satellite-based laser communications system and method for communications between a satellite-based transmitter system and a ground-based receiver over a free space optical link. The satellite-based transmitter system includes an encoder to encode data, a polarization modulator to linearly polarize the encoded data, one or at least two transmitters to transmit the laser beam, and a quarter-wave optical wave plate to circularly polarize the signal to be transmitted. The ground-based receiver includes an automatic gain control to apply AGC to the received data before the polarizations are reversed and the data is decoded. The system enables an increased data throughput and reduces or eliminates the effects of signal fading.

An excitation light source apparatus capable of assuring an excellent optical transmission characteristic even at occurrence of a gain tilt is provided. The excitation light source apparatus comprises an excitation light outputting means, a control signal detection means, a control signal detection means, an excitation light control means, and a multiplexing means. The excitation light outputting means outputs excitation light for Raman amplification. The control signal detection means detects a control signal of the excitation light outputting means from beams of WDM signal light transmitted through optical fibers in an upstream direction and a downstream direction. The excitation light control means controls the excitation light outputting means, based on the control signal. The multiplexing means multiplexes the excitation light and each of the beams of the WDM signal light, and outputs the respective multiplexed beams of light to the optical fiber.

An optical amplification device includes: a polarization demultiplexing unit that separates an optical signal into a first polarized wave and a second polarized wave; a first optical amplification unit that amplifies the first polarized wave by using a first amplification medium; a second optical amplification unit that amplifies the second polarized wave by using a second amplification medium; a first band demultiplexing unit that demultiplexes the first polarized wave into a band component of the first polarized wave and a band component of first phase conjugate light; a second band demultiplexing unit that demultiplexes the second polarized wave into a band component of the second polarized wave and a band component of second phase conjugate light; a signal monitoring unit that measures a first optical power value of either the band component of the first polarized wave or the band component of the first phase conjugate light and a second optical power value of either the band component of the second polarized wave or the band component of the second phase conjugate light; an amplification gain control unit that controls an amplification band and gain of the first amplification medium and an amplification band and gain of the second amplification medium on the basis of the first optical power value and the second optical power value; and a polarization combination unit that multiplexes the band component of the first polarized wave and the band component of the second polarized wave not measured by the signal monitoring unit.

Methods, apparatuses, and systems for packet detection in a point-to-point wireless communication network is disclosed. One method includes receiving, by a receiving node, a plurality of packets, adjusting, by an adjustable gain amplifier of the receiving node, a power level of the received plurality of packets, controlling, by a gain control module, a gain of the adjustable gain amplifier, thereby controlling the power level of the received plurality of packets, monitoring the controlled gain of the gain control module over a period of time, identifying a timing of reception of interfering packets based on the monitoring of the controlled gain of the gain control module over the period of time, and adjustably controlling, by the gain control module, the gain of the adjustable gain amplifier based on the identified timing of reception of the interfering packets.

A gain level control circuit in a wireless distribution system (WDS) is provided. The digital level control circuit receives a number of first digital communications signals having a number of first digital amplitudes and generates a number of second digital communications signals having a number of second digital amplitudes. When a selected second digital amplitude approaches a full-scale digital amplitude represented by a predefined number of binary bits, the gain level control circuit determines a selected first digital communications signal having a selected first digital amplitude causing the selected second digital amplitude to exceed the full-scale digital amplitude and adjusts the selected first digital amplitude to reduce the selected second digital amplitude to lower than or equal to the full-scale digital amplitude. As such, it is possible to overcome digital amplitude clipping without increasing the predefined number of binary bits, thus achieving a calculated balance between performance, complexity, and cost.

Methods, apparatuses, and systems for transmitting information between nodes in a point-to-point wireless communication network is disclosed. One method includes constructing, by a sector of a transmitting node, a packet including data that is to be transmitted to a receiving node in the wireless network, wherein the constructed packet includes a short training field, a channel estimation field, a header field, and a data payload, and transmitting by the sector of the transmitting node, a jamming code before the short training field of the constructed packet, thereby reducing a likelihood that the receiving node will decode a different short training field of an interfering packet before the receiving node decodes the short training field of the constructed packet.

Provided are a control method and system for a cascade hybrid amplifier, in which respective hybrid amplifiers in the cascade hybrid amplifier simultaneously start to implement a pump-starting process comprising: when the hybrid amplifier receives a request to start pumping, determining whether conditions are satisfied, if yes, determining stability of power of an input light of a Raman, starting pumping of an EDFA so that the EDFA enters into an APC operation mode; starting pumping of the Raman, and calculating a gain deviation according to the calculated input light powers before and after pump-starting of the Raman when no reflection alarm exists; and adjusting gain of the Raman according to the gain deviation, and switching to an AGC (automatic gain control) operation mode after the adjustment; and switching the EDFA to the AGC operation mode.

An optical transmission device includes: a first optical amplifier, a WSS (wavelength selective switch), a second optical amplifier and a controller. The first optical amplifier amplifies a received WDM (wavelength division multiplexed) optical signal. The WSS controls optical powers of respective channels multiplexed in the WDM optical signal that is amplified by the first optical amplifier. The second optical amplifier amplifies the WDM optical signal output from the WSS. The controller controls a gain of the first optical amplifier based on initial setting information. The controller corrects the gain of the first optical amplifier such that an average optical power of a plurality of channels multiplexed in the WDM optical signal that is amplified by the first optical amplifier approaches a target level after a specified period of time has elapsed from when the gain of the first optical amplifier is controlled based on the initial setting information.

The present invention relates to the field of communications technologies, and in particular, discloses an automatic cable distribution switch apparatus and system, and an automatic cable distribution switch method. In this solution, the automatic cable distribution switch apparatus is connected to at least two access network devices; even through a terminal cannot gain local power, when needing to switch from a first device, currently connected to the terminal, of an access network to a second device of the access network, the terminal can send an access network device switch instruction to the automatic cable distribution switch apparatus. In this case, when receiving the access network device switch instruction, the automatic cable distribution switch apparatus can switch the terminal from any access network device to another access network device, thereby achieving an effect that automatic cable distribution switch can be performed when the terminal cannot gain local power.