| ReturnTo Theme-Group-Choice | Onelevelup |
| 5K029 | DC digital transmission | |
| H04L25/00 -25/66 | ||
| H04L25/00-25/66 | AA | AA00 PURPOSE AND EFFECTS |
AA01 | AA02 | AA03 | AA04 | AA06 | AA08 | ||||
| . Prevention of malfunction or reduction in the rate of errors | . . Noise countermeasures | . . Measures against waveform deterioration or interference between symbols | . . . Measures against DC fluctuation or bias distortion | . Protection during abnormal operation | . Prevention of abnormal operation | |||||||
| AA11 | AA13 | AA18 | AA20 | |||||||||
| . Increased operating speeds, or improved transmission speeds | . Reduction in the amount of power consumed | . Simplification of hardware | . Adaptations for integrated circuitry | |||||||||
| BB | BB00 INFORMATION SOURCES |
BB01 | BB03 | BB05 | BB06 | |||||||
| . Analog information (e.g., PCM or facsimile) | . Digital data | . On or off information using keys or switches | . . Information for remote control or remote monitoring and control | |||||||||
| CC | CC00 TRANSMISSION MEDIA |
CC01 | CC02 | CC04 | CC05 | CC07 | ||||||
| . Transmission paths through metal wire | . . Coaxial cables | . Optical transmission paths or optical fibers | . . Light-space transmission paths | . Record-reproducing media | ||||||||
| DD | DD00 TRANSMISSION-SYSTEM STRUCTURE |
DD01 | DD02 | DD03 | DD04 | DD05 | ||||||
| . Specific transmission path positions | . . Interfaces between units | . . . Interfaces between terminals or terminal devices | . . . Interfaces between substrates or integrated circuits | . . Processes before and after digital modulation and demodulation | ||||||||
| DD11 | DD12 | DD13 | DD14 | DD15 | ||||||||
| . Transmission path arrangements | . . Point-to-point arrangements | . . Buses or multiple drops | . . Rings or loops | . . Stars | ||||||||
| DD21 | DD22 | DD23 | DD24 | DD25 | DD28 | DD29 | DD30 | |||||
| . Transmission-path structure | . . Serial transmission paths | . . Parallel transmission paths | . . Balanced transmission paths | . . Transmission lines that are also used as source feeds | . Transmitters or transmitting stations | . Receivers or receiving stations | . Repeaters or relay stations | |||||
| EE | EE00 COMMUNICATION SYSTEMS |
EE01 | EE02 | EE04 | EE05 | EE06 | EE07 | EE08 | EE10 | |||
| . Voltage-mode transmission | . Current-mode transmission | . Bit synchronization | . . Burst transmission | . . Transmission of synchronizing signals | . . . Start-stop synchronizing transmission (i.e., start-stop systems) | . . . Synchronizing signals that are sent from the receiving side | . Asynchronous bit transmission | |||||
| EE11 | EE12 | EE13 | EE17 | EE18 | EE19 | EE20 | ||||||
| . Transmission-path code conversion | . . Variants that are adapted to information sources | . . Additional use of code rule violation | . Communication control | . . Handling of transmission units (e.g., serial-parallel conversion) | . . Setting or changing of communication systems | . . Conversion of communication systems | ||||||
| FF | FF00 TRANSMITTED WAVEFORMS |
FF01 | FF02 | FF03 | FF05 | FF06 | FF08 | FF09 | FF10 | |||
| . Transmission path code waveforms | . . n-ary transmission path code waveforms | . . . Trinary transmission path code waveforms | . Waveforms other than those of the transmission path codes | . . Insertion of narrow-width pulses | . Narrow-band or restricted-band waveforms | . DC component-suppressed waveforms | . Waveforms that have clock components | |||||
| GG | GG00 TRANSMITTING SECTIONS |
GG01 | GG03 | GG05 | GG07 | GG10 | ||||||
| . Synchronization with information sources | . Encoding to transmission path codes | . Pre-equalizing or predistortion | . Line drivers or transmission-output circuits | . Communication control at the transmitting side | ||||||||
| HH | HH00 RECEIVING SECTIONS |
HH01 | HH02 | HH03 | HH05 | HH06 | HH08 | HH09 | HH10 | |||
| . Line receivers or amplification | . . Amplification using negative resistance elements | . . Automatic gain control (AGC) | . Equalization | . . Quantified feedback | . Level discrimination or amplitude differentiation | . . Comparison with mean values or peak values | . . Differentiation of amplitude integration values | |||||
| HH11 | HH13 | HH14 | HH16 | HH17 | ||||||||
| . Points where amplitude changes are detected | . Sampling | . . Multiple sampling points within a single bit | . Discrimination that also uses values before and after the discrimination points | . . Use of the majority of the sampled values | ||||||||
| HH21 | HH22 | HH23 | HH24 | HH26 | HH27 | HH29 | HH30 | |||||
| . Decoding from transmission path codes | . . Use of spacing between amplitude change points | . . . Use of gate pulses | . . Decoding that detects and corrects errors | . Synchronization with transmitting sections, or detection of synchronizing signals | . . Selection of clock series | . Communication control at the receiving side | . . Determination of the presence or absence of transmitted waveforms | |||||
| JJ | JJ00 SECTIONS THAT CONNECT WITH TRANSMISSION PATHS |
JJ01 | JJ03 | JJ04 | JJ06 | JJ08 | JJ10 | |||||
| . Photocouplers | . Transformer coupling | . . Coupling accompanied by modulation and demodulation | . Connectors that use electrical contact | . Matching or suppression of reflected waves | . Connection or switching | |||||||
| KK | KK00 MONITORING AND TESTING |
KK01 | KK03 | KK05 | KK06 | |||||||
| . In-service monitoring and testing | . Out-of-service monitoring and testing | . Control following detection of disturbances | . . Halt of signal transmission | |||||||||
| KK11 | KK12 | KK13 | KK14 | KK15 | ||||||||
| . Types of disturbances | . . Input- signal disconnection | . . . Transmission-path disconnection | . . . Transmission-path short-circuits | . . Power-source disturbances | ||||||||
| KK21 | KK22 | KK23 | KK24 | KK25 | KK26 | KK27 | KK28 | KK30 | ||||
| . Measured values or detected values | . . Time or phase | . . . Jitter | . . Amplitude | . . Eye patterns | . . Frequency characteristics or frequency distribution | . . Number of errors or rate of errors | . . Noise or signal-to-noise ratio | . Location of fault points | ||||
| KK31 | KK32 | KK33 | KK35 | |||||||||
| . Use of monitoring, testing, or control signals | . . Use of pulse-trio signals | . . Use of phase-sensing signals | . Signal reflection | |||||||||
| LL | LL00 BASIC CIRCUITS (I.E., AS EXTRACTED FROM CLAIMS) |
LL01 | LL02 | LL03 | LL05 | LL06 | LL08 | LL10 | ||||
| . Filters | . . Differentiation circuits | . . Integrating circuits | . Limiters or clippers | . Clampers (i.e., clamp circuits) | . Delay circuits or monostable multivibrators | . Oscillation circuits | ||||||
| LL11 | LL12 | LL14 | LL15 | LL16 | LL17 | LL19 | LL20 | |||||
| . Logic gates (e.g., AND or OR) | . . EXOR or EXNOR | . Memory circuits or hold circuits | . . Flip-flops | . . Shift registers | . . Memories that have addresses (e.g., ROM) | . Counters | . Central processing units (CPU) |