CPC - H04L - 2021.08 H04L TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION ({coding or ciphering apparatus for cryptographic or other purposes involving the need for secrecy G09C;} arrangements common to telegraphic and telephonic communication H04M) Definition statement This place covers: Transmission of signals having been supplied in digital form, e.g. data transmission, telegraphic communication, or methods or arrangements for monitoring. As the scope of H04L covers a diversity of subject matter, the user is referred to the definitions for the main groups of H04L. The following list is intended to assist the user. Systems: • characterised by the code used, e.g. Morse or Baudot; details, see definition for groups H04L 15/00, H04L 17/00, H04L 13/00; • step by step systems, see definition for group H04L 19/00; • mosaic printer telegraph systems, see definition for group H04L 21/00; • systems not covered by H04L 15/00-H04L 21/00, see definition for group H04L 23/00; • baseband systems, see definition for group H04L 25/00; • modulated carrier systems, see definition for group H04L 27/00; • data switching networks, see definition for group H04L 12/00. Arrangements of general application: • security: errors; secrecy, see definition for groups H04L 1/00, H04L 9/00; • multiple communications, see definition for groups H04L 5/00, H04L 7/00; • other arrangements, apparatus or systems, see definition for group H04L 29/00. network architectures or network communication protocols for network security H04L 63/00 References Limiting references This place does not cover: Coding or ciphering apparats for cryptographic or other purposes G09C involving the need for secrecy Arrangements applicable to telegraphic or telephonic communication H04M Informative references Attention is drawn to the following places, which may be of interest for search: Typewriters B41J Order telegraphs, fire or police telegraphs G08B Visual telegraphy G08B Teleautographic systems G08C Coding, decoding or code conversion, in general H03M Spread spectrum techniques in general H04B 1/69 1 H04L (continued) CPC - H04L - 2021.08 Informative references Selecting H04Q H04L 1/00 Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L 7/00)} Definition statement This place covers: Codes for error detection or error correction, i.e. theoretical code construction and coding circuit architecture designs are classified in H04M 13/00; the application of such codes in transmission systems is covered by H04L 1/00 subgroups. References Limiting references This place does not cover: Correcting synchronisation H04L 7/00 Informative references Attention is drawn to the following places, which may be of interest for search: Computer systems G06F Error correction or detection in electrical digital data processing G06F 11/00 - G06F 11/20 Coin-feed or like apparatus with coded identity card or credit card G07F 7/08 Error correction in speech coding G10L 19/005 Codes for error detection or error correction per se, i.e. theoretical code H03M 13/00 construction and coding circuit architecture designs Transmission H04B Diversity Systems for radio transmission systems H04B 7/02 Error detection and correction for transmission of compressed video (e.g. H04N 19/89, MPEG) H04N 21/2383 Special rules of classification Classification into the main group H04L 1/00 itself should be avoided and instead its relevant subgroups should be used by identifying the particular error technique used. If no other group can be assigned for error control applicable to transmission systems, then it may be assigned to this main group. In addition an Indexing Code can be given under H04L 2001/0092 for network topology, which is of interest to H04L 1/00. Synonyms and Keywords In patent documents, the following abbreviations are often used: AM Acknowledged Mode AMC Adaptive Modulation and Coding 2 H04L 1/00 (continued) CPC - H04L - 2021.08 Synonyms and Keywords AMR Adaptive Multirate ARQ Automatic Repeat reQuest BCCH Broadcast Control Channel BCH Broadcast Channel BER Bit Error Rate BLER Block Error Rate BPSK Binary Phase Shift Keying BW Bandwidth C-RNTI Cell Radio Network Temporary Identity CDMA Code Division Multiple Access CE Cyclic Extension CP Cyclic Prefix CQI Channel Quality Indicator CRC Cyclic Redundancy Check CSI Channel State Information DCCH Dedicated Control Channel DCI Downlink Control Information DFT Discrete Fourier Transform DL Downlink DL-SCH Downlink Shared Channel DRA Dynamic Resource Allocation DRX Discontinuous Reception DTCH Dedicated Traffic Channel DTX Discontinuous Transmission E-UTRA Evolved UMTS Terrestrial Radio Access E-UTRAN Evolved UMTS Terrestrial Radio Access Network EPC Evolved Packet Core FDD Frequency Division Duplex FDM Frequency Division Multiplexing FDMA Frequency Division Multiple Access FEC Forward Error Correction H-ARQ Hybrid ARQ HSDPA High Speed Downlink Packet Access HSUPA High Speed Uplink Packet Access IP Internet Protocol IPSec Internet Protocol Security LTE Long Term Evolution MAC Medium Access Control MAC Message Authentication NACK Negative ACK 3 H04L 1/00 (continued) CPC - H04L - 2021.08 Synonyms and Keywords NAS Non-Access Stratum OFDM Orthogonal Frequency Division Multiplexing PAPR Peak-to-Average Power Ratio PDCCH Physical Dedicated Control Channel PDCP Packet Data Convergence Protocol PHICH Physical Hybrid ARQ Indicator Channel PUCCH Physical Uplink Control Channel PUSCH Physical Uplink Shared Channel QAM Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Keying RRC Radio Resource Control SDMA Space (or Spatial) Division Multiple Access SIMO Single Input Multiple Output SIP Session Initiation Protocol SIR Signal-to-Interference Ratio STC Space Time Coding UEP Unequal error protections UM Unacknowledged Mode VoIP Voice over Internet Protocol WCDMA Wideband Code Division Multiple Access H04L 1/0001 {Systems modifying transmission characteristics according to link quality, e.g. power backoff (adaptive data allocation for multicarrier modulation H04L 5/0044; controlling transmission power for radio systems H04W 52/04)} Definition statement This place covers: General link adaptation techniques, including power control for non-radio links, and handshaking procedures involving link adaptation. References Limiting references This place does not cover: Allocation of payload for multicarrier modulation system H04L 5/0044 Control of transmission power in radio systems H04W 52/04 Informative references Attention is drawn to the following places, which may be of interest for search: Splitting-up the transmission path, e.g. time, frequency etc. H04L 5/0001 4 H04L 1/0001 (continued) CPC - H04L - 2021.08 Informative references Allocating sub-channels of the transmission path H04L 5/003 Negotiation of transmission parameters unrelated to channel quality H04L 5/1438 Adaptation of equalizers (attention: Indexing Code) H04L 25/03019, H04L 2025/03535 Transmit line pre-equalization, e.g. precoding, MIMO calibration H04L 25/03343 Multichannel equalizers (attention: Indexing Code) H04L 2025/03426 Adaptation of timing of transmitters in a network H04J 3/06 Mode change for facsimile transmission H04N 1/3333 Network traffic and resource management H04W 28/00 Communication route selection based on channel quality H04W 40/12 Wireless resource allocation H04W 72/04 Special rules of classification Adaptive techniques are covered by specific subgroups under H04L 1/0001 unless they are other aspects, e.g. frequency hopping, adaptive slew rate, adaptive interleaving, DSL power back-off. ARQ adaptive retransmission aspects should be classified mainly under the H04L 1/16, H04L 1/18 subgroups. H04L 1/0002 {by adapting the transmission rate} Definition statement This place covers: The end raw rate at which bits are transmitted through the channel, e.g. after encoding. References Informative references Attention is drawn to the following places, which may be of interest for search: Allocation of payload H04L 5/0044 Management of data rate of a bus H04L 12/4013 Network nodes adapting their rate to physical link properties H04L 12/40136 Rate modification H04L 47/25 Explicit feedback to the source H04L 47/26 Negotiation of communication rate in wireless communication H04W 28/22 Power control taking into account the transmission rate H04W 52/267 5 CPC - H04L - 2021.08 H04L 1/0003 {by switching between different modulation schemes} Definition statement This place covers: Also adaptive CDMA and direct sequence spread spectrum is covered by this subgroup. References Limiting references This place does not cover: Management of data rate of a bus H04L 12/4013 Network nodes adapting their rate to physical link properties H04L 12/40136 CDMA system aspects H04B 1/00 Negotiation of communication rate in wireless communication systems; H04W 28/22 network traffic / resource management Special rules of classification Adaptation of modulation is classified in H04L 1/0003 even if line bitrate remains constant, e.g. switch- over from 8-QAM to 8-PSK. Adaptation of modulation and coding schemes (MCS/AMR) are classifed also under H04L 1/0009. Particular ARQ physical mapping aspects should be classified mainly under the H04L 1/1893 or H04L 1/1861. H04L 1/0004 {applied to control information} Special rules of classification If the adaptation concerns both control and payload then only H04L 1/0003 is used. H04L 1/0005 {applied to payload information} Special rules of classification If the adaptation concerns both control and payload then only