Transmission systems employing electromagnetic waves other than radio-waves

HELECTRICITY H04Electric communication H04BTRANSMISSION

H04B10/00Transmission systems employing electromagnetic waves other than radio-waves

H04B10/03Arrangements for fault recovery H04B10/032using working and protection systems H04B10/035using loopbacks H04B10/038using bypasses H04B10/07Arrangements for monitoring or testing transmission systems Arrangements for fault measurement of transmission systems H04B10/0705Prevention or detection of unauthorized access H04B10/071using a reflected signal H04B10/073using an out-of-service signal H04B10/0731Testing or characterisation of optical devices H04B10/075using an in-service signal H04B10/077using a supervisory or additional signal H04B10/0771Fault location on the transmission path H04B10/0773Network aspects H04B10/0775Performance monitoring and measurement of transmission parameters H04B10/0777Monitoring line amplifier or line repeater equipment H04B10/0779Monitoring line transmitter or line receiver equipment H04B10/079using measurements of the data signal H04B10/0791Fault location on the transmission path H04B10/0793Network aspects H04B10/0795Performance monitoring; Measurement of transmission parameters H04B10/07951Monitoring or measuring chromatic dispersion or PMD H04B10/07953Monitoring or measuring OSNR, BER or Q H04B10/07955Monitoring or measuring power H04B10/07957Monitoring or measuring wavelength H04B10/0797Monitoring line amplifier or line repeater equipment H04B10/0799Monitoring line transmitter or line receiver equipment H04B10/11Arrangements specific to free-space transmission H04B10/112Line-of-sight transmission over an extended range H04B10/1121One-way transmission H04B10/1123Bidirectional transmission H04B10/1125using a single common optical path H04B10/1127using two distinct parallel optical paths H04B10/1129Arrangements for outdoor wireless networking of information H04B10/114Indoor or close-range type systems H04B10/1141One-way transmission H04B10/1143Bidirectional transmission H04B10/1149Arrangements for indoor wireless networking of information H04B10/116Visible light communication H04B10/118specially adapted for satellite communication H04B10/12Transmission through light guides H04B10/14Terminal stations H04B10/142Coherent homodyne or heterodyne systems H04B10/152Non-coherent direct-detection systems H04B10/22Transmission between two stations which are mobile relative to each other H04B10/225using optical fibre links H04B10/25Arrangements specific to fibre transmission H04B10/2503Bidirectional transmission H04B10/2504Transmission components H04B10/2507for the reduction or elimination of distortion or dispersion H04B10/25073using spectral equalisation H04B10/25077using soliton propagation H04B10/2513due to chromatic dispersion H04B10/25133including a lumped electrical or optical dispersion compensator ; optical dispersion compensators involving optical fibres per se G02B6/293 H04B10/25137using pulse shaping at the transmitter H04B10/2519using Bragg gratings H04B10/2525using dispersion-compensating fibres H04B10/25253with dispersion management H04B10/2531using spectral inversion H04B10/2537due to scattering processes H04B10/2543due to fibre non-linearities H04B10/255Self-phase modulation [SPM] H04B10/2557Cross-phase modulation [XPM] H04B10/2563Four-wave mixing [FWM] H04B10/2569due to polarisation mode dispersion [PMD] H04B10/2572due to forms of polarisation-dependent distortion other than PMD H04B10/2575Radio-over-fibre H04B10/25751Optical arrangements for CATV or video distribution H04B10/25752Optical arrangements for wireless networks H04B10/25753Distribution optical network H04B10/25754Star network topology H04B10/25755Ring network topology H04B10/25756Bus network topology H04B10/25758between a central unit and a single remote unit by means of an optical fibre H04B10/25759Details of the reception of RF signal or the optical conversion before the optical fibre H04B10/2581Multimode transmission H04B10/2587using a single light source for multiple stations H04B10/27Arrangements for networking H04B10/271Combination of different networks H04B10/272Star-type networks or tree-type networks H04B10/2725Star-type networks without a headend H04B10/275Ring-type networks H04B10/2755Ring-type networks with a headend H04B10/278Bus-type networks H04B10/29Repeaters H04B10/291in which processing or amplification is carried out without conversion of the main signal from optical form H04B10/2912characterised by the medium used for amplification or processing H04B10/2914using lumped semiconductor optical amplifiers [SOA] H04B10/2916using Raman or Brillouin amplifiers H04B10/2918Two-way repeaters H04B10/293Signal power control H04B10/2931using AGC H04B10/2933considering the whole optical path H04B10/2935with a cascade of amplifiers H04B10/2937Systems with a repeater placed only at the beginning or the end of the system, i.e. repeaterless systems H04B10/2939Network aspects H04B10/294in a multiwavelength system H04B10/2941using an equalising unit H04B10/2942using automatic gain control [AGC] H04B10/296Transient power control H04B10/297Bidirectional amplification H04B10/2971A single amplifier for both directions H04B10/2972Each direction being amplified separately H04B10/299Signal waveform processing H04B10/30Transmission systems employing beams of corpuscular radiation H04B10/40Transceivers H04B10/43using a single component as both light source and receiver H04B10/50Transmitters H04B10/501Structural aspects H04B10/502LED transmitters H04B10/503Laser transmitters H04B10/504using direct modulation H04B10/505using external modulation H04B10/5051using a series H04B10/5053using a parallel H04B10/5055using a pre-coder H04B10/5057using a feedback signal generated by analysing the optical output H04B10/50572to control the modulating signal amplitude including amplitude distortion H04B10/50575to control the modulator DC bias H04B10/50577to control the phase of the modulating signal H04B10/5059using a feed-forward signal generated by analysing the optical or electrical input H04B10/50593to control the modulating signal amplitude including amplitude distortion H04B10/50595to control the modulator DC bias H04B10/50597to control the phase of the modulating signal H04B10/506Multi-wavelength transmitters H04B10/508Pulse generation H04B10/516Details of coding or modulation H04B10/5161Combination of different modulation schemes H04B10/5162Return-to-zero modulation schemes H04B10/5165Carrier suppressed; Single sideband; Double sideband or vestigial H04B10/5167Duo-binary; Alternative mark inversion; Phase shaped binary transmission H04B10/524Pulse modulation H04B10/532Polarisation modulation H04B10/54Intensity modulation H04B10/541Digital intensity or amplitude modulation H04B10/548Phase or frequency modulation H04B10/556Digital modulation H04B10/5561Digital phase modulation H04B10/5563Digital frequency modulation H04B10/564Power control H04B10/572Wavelength control H04B10/58Compensation for non-linear transmitter output H04B10/588in external modulation systems H04B10/60Receivers H04B10/61Coherent receivers i.e., optical receivers using an optical local oscillator H04B10/611Intradyne, i.e., coherent receivers with a free running local oscillator having a frequency close but not phase-locked to the carrier signal H04B10/612for optical signals modulated with a format different from binary or higher-order PSK [X-PSK] H04B10/613including phase diversity, e.g., having in-phase and quadrature branches, as in QPSK coherent receivers H04B10/614comprising one or more polarization beam splitters H04B10/615Arrangements affecting the optical part of the receiver H04B10/6151comprising a polarization controller at the receiver's input stage H04B10/616Details of the electronic signal processing in coherent optical receivers H04B10/6161Compensation of chromatic dispersion H04B10/6162Compensation of polarization related effects, e.g., PMD, PDL H04B10/6163Compensation of non-linear effects in the fiber optic link H04B10/6164Estimation or correction of the frequency offset between the received optical signal and the optical local oscillator H04B10/6165Estimation of the phase of the received optical signal, phase error estimation or phase error correction H04B10/6166Polarization demultiplexing, tracking or alignment of orthogonal polarization components H04B10/63Homodyne , i.e., coherent receivers where the local oscillator is locked in frequency and phase to the carrier signal H04B10/64Heterodyne , i.e., coherent receivers where, after the opto-electronic conversion, an electrical signal at an intermediate frequency [fIF] is obtained H04B10/66Non-coherent receivers H04B10/67Optical arrangements in the receiver H04B10/671for controlling the input optical signal H04B10/672for controlling the power of the input optical signal H04B10/673using an optical preamplifier H04B10/674using a variable optical attenuator H04B10/675for controlling the optical bandwidth of the input signal H04B10/676for all-optical demodulation of the input optical signal H04B10/677for differentially modulated signal H04B10/69Electrical arrangements in the receiver H04B10/691Arrangements for optimizing the photodetector in the receiver H04B10/6911Photodiode bias control H04B10/693Arrangements for optimizing the preamplifier in the receiver H04B10/6931Automatic gain control of the preamplifier H04B10/6932Bandwidth control of bit rate adaptation H04B10/6933Offset control of the differential preamplifier H04B10/695Arrangements for optimizing the decision element in the receiver H04B10/697Arrangements for reducing noise and distortion H04B10/6971using equalisation H04B10/6972using passive filtering H04B10/6973using noise matching networks H04B10/70Photonic quantum communication H04B10/80Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70 H04B10/801using optical interconnects H04B10/802for isolation H04B10/803Free space interconnects H04B10/806Arrangements for feeding power H04B10/807Optical power feeding H04B10/808Electrical power feeding of an optical transmission system H04B10/85Protection from unauthorised access H04B10/90Non-optical transmission systems