| 1/00 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) |
| 1/02 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by diversity reception (in general H04B 7/02) |
| 1/04 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by diversity reception (in general H04B 7/02) using frequency diversity |
| 1/06 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by diversity reception (in general H04B 7/02) using space diversity |
| 1/08 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by repeating transmission, e.g. Verdan system |
| 1/12 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by using return channel |
| 1/14 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by using return channel in which the signals are sent back to the transmitter to be checked |
| 1/16 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals |
| 1/18 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals Automatic repetition systems, e.g. van Duuren system |
| 1/20 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) using signal-quality detector |
| 1/22 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) using redundant apparatus to increase reliability |
| 1/24 | Arrangements for detecting or preventing errors in the information received (correcting synchronisation H04L 7/00; arrangements in the transmission path H04B) Testing correct operation |
| 5/00 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) |
| 5/02 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal |
| 5/04 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal the signals being represented by different amplitudes or polarities, e.g. quadriplex |
| 5/06 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal the signals being represented by different frequencies (combined with time-division multiplexing H04L 5/26) |
| 5/08 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal the signals being represented by different frequencies (combined with time-division multiplexing H04L 5/26) each combination of signals in different channels being represented by a fixed frequency |
| 5/10 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal the signals being represented by different frequencies (combined with time-division multiplexing H04L 5/26) with dynamo-electric generation of carriers; with mechanical filters or demodulators |
| 5/12 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Channels characterised by the type of signal the signals being represented by different phase modulations of a single carrier |
| 5/14 | Arrangements affording multiple use of the transmission path (multiplex communication in general H04J) Two-way operation using the same type of signal, i.e. duplex (conditioning for two-way transmission in general H04B 3/2) |