IPC-Stelle: H04L 12/66 [Version 2017.01]

SymbolTypTitel
HSKELECTRICITY
H04KLELECTRIC COMMUNICATION TECHNIQUE
H04LUKLTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) [4]
H04L 1/00HGRArrangements for detecting or preventing errors in the information received [1, 2006.01]
H04L 1/02UGR1
.by diversity reception [1, 2006.01]
H04L 1/04UGR2
. .using frequency diversity [1, 2006.01]
H04L 1/06UGR2
. .using space diversity [1, 2006.01]
H04L 1/08UGR1
.by repeating transmission, e.g. Verdan system [1, 2006.01]
H04L 1/12UGR1
.by using return channel [1, 2006.01]
H04L 1/14UGR2
. .in which the signals are sent back to the transmitter to be checked [1, 2006.01]
H04L 1/16UGR2
. .in which the return channel carries supervisory signals, e.g. repetition request signals [1, 2006.01]
H04L 1/18UGR3
. . .Automatic repetition systems, e.g. van Duuren system [1, 2006.01]
H04L 1/20UGR1
.using signal-quality detector [3, 2006.01]
H04L 1/22UGR1
.using redundant apparatus to increase reliability [3, 2006.01]
H04L 1/24UGR1
.Testing correct operation [3, 2006.01]
H04L 5/00HGRArrangements affording multiple use of the transmission path [1, 2006.01]
H04L 5/02UGR1
.Channels characterised by the type of signal [1, 2006.01]
H04L 5/04UGR2
. .the signals being represented by different amplitudes or polarities, e.g. quadriplex [1, 2006.01]
H04L 5/06UGR2
. .the signals being represented by different frequencies (combined with time-division multiplexing H04L 5/26) [1, 2006.01]
H04L 5/08UGR3
. . .each combination of signals in different channels being represented by a fixed frequency [1, 2006.01]
H04L 5/10UGR3
. . .with dynamo-electric generation of carriers; with mechanical filters or demodulators [1, 2006.01]
H04L 5/12UGR2
. .the signals being represented by different phase modulations of a single carrier [1, 2006.01]
H04L 5/14UGR1
.Two-way operation using the same type of signal, i.e. duplex [1, 2006.01]
H04L 5/16UGR2
. .Half-duplex systems; Simplex/duplex switching; Transmission of break signals [1, 2006.01]
H04L 5/18UGR2
. .Automatic changing of the traffic direction [1, 2006.01]
H04L 5/20UGR1
.using different combinations of lines, e.g. phantom working [1, 2006.01]
H04L 5/22UGR1
.using time-division multiplexing [1, 2006.01]
H04L 5/24UGR2
. .with start-stop synchronous converters [1, 2006.01]
H04L 5/26UGR2
. .combined with the use of different frequencies [1, 2006.01]
H04L 7/00HGRArrangements for synchronising receiver with transmitter [1, 2006.01]
H04L 7/02UGR1
.Speed or phase control by the received code signals, the signals containing no special synchronisation information [1, 2006.01]
H04L 7/027UGR2
. .extracting the synchronising or clock signal from the received signal spectrum, e.g. by using a resonant or bandpass circuit [5, 2006.01]
H04L 7/033UGR2
. .using the transitions of the received signal to control the phase of the synchronising-signal- generating means, e.g. using a phase-locked loop [5, 2006.01]
H04L 7/04UGR1
.Speed or phase control by synchronisation signals [1, 2006.01]
H04L 7/06UGR2
. .the synchronisation signals differing from the information signals in amplitude, polarity, or frequency [1, 2006.01]
H04L 7/08UGR2
. .the synchronisation signals recurring cyclically [1, 2006.01]
H04L 7/10UGR2
. .Arrangements for initial synchronisation [1, 2006.01]
H04L 9/00HGRArrangements for secret or secure communication [1, 2006.01]
H04L 9/06UGR1
.the encryption apparatus using shift registers or memories for blockwise coding, e.g. D.E.S. systems [5, 2006.01]
H04L 9/08UGR1
.Key distribution [5, 2006.01]
H04L 9/10UGR1
.with particular housing, physical features or manual controls [5, 2006.01]
H04L 9/12UGR1
.Transmitting and receiving encryption devices synchronised or initially set up in a particular manner [5, 2006.01]
H04L 9/14UGR1
.using a plurality of keys or algorithms [5, 2006.01]
H04L 9/16UGR2
. .the keys or algorithms being changed during operation [5, 2006.01]
H04L 9/18UGR1
.Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems [5, 2006.01]
H04L 9/20UGR2
. .Pseudorandom key sequence combined element-for-element with data sequence [5, 2006.01]
H04L 9/22UGR3
. . .with particular pseudorandom sequence generator [5, 2006.01]
H04L 9/24UGR4
. . . .sequence produced by more than one generator [5, 2006.01]
H04L 9/26UGR4
. . . .producing a nonlinear pseudorandom sequence [5, 2006.01]
H04L 9/28UGR1
.using particular encryption algorithm [5, 2006.01]
H04L 9/30UGR2
. .Public key, i.e. encryption algorithm being computationally infeasible to invert and users' encryption keys not requiring secrecy [5, 2006.01]
H04L 9/32UGR1
.including means for verifying the identity or authority of a user of the system [5, 2006.01]
H04L 9/34UGR1
.Bits, or blocks of bits, of the telegraphic message being interchanged in time [5, 2006.01]
H04L 9/36UGR1
.with means for detecting characters not meant for transmission [5, 2006.01]
H04L 9/38UGR1
.Encryption being effected by mechanical apparatus, e.g. rotating cams, switches, keytape punchers [5, 2006.01]
H04L 12/00HGRData switching networks (interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F 13/00) [5, 2006.01]
H04L 12/02UGR1
.Details [5, 2006.01]
H04L 12/04UGR2
. .Switchboards [5, 2006.01]
H04L 12/06UGR2
. .Answer-back mechanisms or circuits [5, 2006.01]
H04L 12/08UGR2
. .Allotting numbers to messages; Counting characters, words or messages [5, 2006.01]
H04L 12/10UGR2
. .Current supply arrangements [5, 2006.01]
H04L 12/12UGR2
. .Arrangements for remote connection or disconnection of substations or of equipment thereof [5, 2006.01]
H04L 12/14UGR2
. .Charging arrangements [5, 2006.01]
H04L 12/16UGR2
. .Arrangements for providing special services to substations [5, 2006.01]
H04L 12/18UGR3
. . .for broadcast or conference [5, 2006.01]
H04L 12/20UGR3
. . .for converting transmission speed from the inherent speed of a substation to the inherent speed of other substations [5, 2006.01]
H04L 12/22UGR2
. .Arrangements for preventing the taking of data from a data transmission channel without authorisation (means for verifying the identity or the authority of a user of a secure or secret communication system H04L 9/32) [5, 2006.01]
H04L 12/24UGR2
. .Arrangements for maintenance or administration [5, 2006.01]
H04L 12/26UGR2
. .Monitoring arrangements; Testing arrangements [5, 2006.01]
H04L 12/28UGR1
.characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] (wireless communication networks H04W) [5, 6, 2006.01]
H04L 12/40UGR2
. .Bus networks [5, 6, 2006.01]
H04L 12/403UGR3
. . .with centralised control, e.g. polling [6, 2006.01]
H04L 12/407UGR3
. . .with decentralised control [6, 2006.01]
H04L 12/413UGR4
. . . .with random access, e.g. carrier-sense multiple-access with collision detection (CSMA-CD) [6, 2006.01]
H04L 12/417UGR4
. . . .with deterministic access, e.g. token passing [6, 2006.01]
H04L 12/42UGR2
. .Loop networks [5, 6, 2006.01]
H04L 12/423UGR3
. . .with centralised control, e.g. polling [6, 2006.01]
H04L 12/427UGR3
. . .with decentralised control [6, 2006.01]
H04L 12/43UGR4
. . . .with synchronous transmission, e.g. time division multiplex (TDM), slotted rings [6, 2006.01]
H04L 12/433UGR4
. . . .with asynchronous transmission, e.g. token ring, register insertion [6, 2006.01]
H04L 12/437UGR3
. . .Ring fault isolation or reconfiguration [6, 2006.01]
H04L 12/44UGR2
. .Star or tree networks [5, 6, 2006.01]
H04L 12/46UGR2
. .Interconnection of networks [5, 6, 2006.01]
H04L 12/50UGR1
.Circuit switching systems, i.e. systems in which the path is physically permanent during the communication [5, 6, 2006.01]
H04L 12/52UGR2
. .using time division techniques (in digital transmission systems H04L 5/22) [5, 6, 2006.01]
H04L 12/54UGR1
.Store-and-forward switching systems (packet switching systems H04L 12/70) [5, 6, 2006.01, 2013.01]
H04L 12/58UGR2
. .Message switching systems [5, 6, 2006.01]
H04L 12/60UGR3
. . .Manual relay systems, e.g. push-button switching [5, 6, 2006.01]
H04L 12/62UGR4
. . . .with perforated tape storage [5, 6, 2006.01]
H04L 12/64UGR1
.Hybrid switching systems [5, 6, 2006.01]
H04L 12/66UGR1
.Arrangements for connecting between networks having differing types of switching systems, e.g. gateways [5, 6, 2006.01]
H04L 12/70UGR1
.Packet switching systems [2013.01]
H04L 12/701UGR2
. .Routing or path finding [2013.01]
H04L 12/703UGR3
. . .Route fault prevention or recovery, e.g. rerouting, route redundancy, virtual router redundancy protocol [VRRP] or hot standby router protocol [HSRP] [2013.01]
H04L 12/705UGR4
. . . .Loop or livelock prevention, e.g. time to live [TTL] or spanning tree [2013.01]
H04L 12/707UGR4
. . . .using path redundancy [2013.01]
H04L 12/709UGR5
. . . . .using M+N parallel active paths [2013.01]
H04L 12/711UGR5
. . . . .using M:N active or standby paths [2013.01]
H04L 12/713UGR4
. . . .using node redundancy, e.g. VRRP [2013.01]
H04L 12/715UGR3
. . .Hierarchical routing, e.g. clustered networks or inter-domain routing [2013.01]
H04L 12/717UGR3
. . .Centralised routing [2013.01]
H04L 12/721UGR3
. . .Routing procedures, e.g. shortest path routing, source routing, link state routing or distance vector routing [2013.01]
H04L 12/723UGR4
. . . .Label or tag based routing, e.g. multi-protocol label switching [MPLS] or generalised multi-protocol label switching [GMPLS] [2013.01]
H04L 12/725UGR4
. . . .Selecting a path with suitable quality of service [QoS] [2013.01]
H04L 12/727UGR5
. . . . .Selecting a path with minimum delay [2013.01]
H04L 12/729UGR5
. . . . .Selecting a path with suitable bandwidth or throughput [2013.01]
H04L 12/733UGR4
. . . .Selecting a path with minimum length or minimum hop count [2013.01]
H04L 12/735UGR4
. . . .Disjoint routing, e.g. path disjoint or node disjoint [2013.01]
H04L 12/741UGR3
. . .Header address processing for routing, e.g. table lookup [2013.01]
H04L 12/743UGR4
. . . .using hashing techniques [2013.01]
H04L 12/745UGR4
. . . .using longest matching prefix [2013.01]
H04L 12/747UGR4
. . . .Address caching [2013.01]
H04L 12/749UGR4
. . . .Address processing over inter-domain or inter-network, e.g. mapping different addresses between IPv6 and IPv4 networks for routing [2013.01]
H04L 12/751UGR3
. . .Topology update or discovery [2013.01]
H04L 12/753UGR4
. . . .Routing tree discovery, e.g. converting from mesh topology to tree topology [2013.01]
H04L 12/755UGR4
. . . .Topology update consistency, e.g. link state advertisement [LSA], time stamping or sequence numbers in the updates [2013.01]
H04L 12/757UGR4
. . . .Synchronised activation of routing updates, e.g. delaying or holding routing table updates [2013.01]
H04L 12/759UGR4
. . . .Dynamic adaptation of update interval, e.g. event-driven updates [2013.01]
H04L 12/761UGR3
. . .Broadcast or multicast routing [2013.01]
H04L 12/763UGR3
. . .Shortcut routing, e.g. next hop resolution protocol [NHRP] [2013.01]
H04L 12/771UGR3
. . .Router architecture [2013.01]
H04L 12/773UGR4
. . . .for supporting layer 3 switching, e.g. IP switching, cell switch relay [CSR] or tag switching [2013.01]
H04L 12/775UGR4
. . . .multiple routing entities, e.g. multiple software or hardware instances [2013.01]
H04L 12/781UGR3
. . .Multiprotocol routing, e.g. for protocol adaptation between IPv4 and IPv6 or dual stack [2013.01]
H04L 12/801UGR2
. .Flow control or congestion control [2013.01]
H04L 12/803UGR3
. . .Load balancing, e.g. traffic distribution over multiple links [2013.01]
H04L 12/805UGR3
. . .Determination of the optimum packet size, e.g. maximum transmission unit [MTU] [2013.01]
H04L 12/807UGR3
. . .Calculation or update of the congestion window [2013.01]
H04L 12/811UGR3
. . .Bitrate adaptation in active flows [2013.01]
H04L 12/813UGR4
. . . .Policy-based control, e.g. policing [2013.01]
H04L 12/815UGR4
. . . .Shaping [2013.01]
H04L 12/819UGR4
. . . .Leaky bucket [2013.01]
H04L 12/823UGR4
. . . .Packet dropping [2013.01]
H04L 12/825UGR4
. . . .Adaptive control, at the source or intermediate nodes, upon congestion feedback, e.g. X-on X-off [2013.01]
H04L 12/827UGR5
. . . . .sent by intermediate network nodes [2013.01]
H04L 12/829UGR5
. . . . .sent by the destination endpoint [2013.01]
H04L 12/833UGR4
. . . .Marking packets or altering packet priority upon congestion or for congestion prevention [2013.01]
H04L 12/835UGR4
. . . .using buffer capacity information at the endpoints or transit nodes [2013.01]
H04L 12/841UGR3
. . .Flow control actions using time consideration, e.g. round trip time [RTT] [2013.01]
H04L 12/851UGR3
. . .Traffic type related actions, e.g. QoS or priority [2013.01]
H04L 12/853UGR4
. . . .for real time traffic [2013.01]
H04L 12/855UGR4
. . . .for signalling traffic, e.g. operations, administration and maintenance [OAM] or acknowledge [ACK] packets [2013.01]
H04L 12/857UGR4
. . . .Mapping QoS constraints between layers or between different networks [2013.01]
H04L 12/859UGR4
. . . .Flow control actions based on the nature of the application, e.g. controlling web browsing or e-mail traffic [2013.01]
H04L 12/861UGR3
. . .Packet buffering or queuing arrangements; Queue scheduling [2013.01]
H04L 12/863UGR4
. . . .Queue scheduling, e.g. Round Robin [2013.01]
H04L 12/865UGR5
. . . . .Priority-based scheduling [2013.01]
H04L 12/867UGR5
. . . . .Fair share scheduling [2013.01]
H04L 12/869UGR5
. . . . .Multilevel scheduling; Hierarchical scheduling [2013.01]
H04L 12/873UGR5
. . . . .Bandwidth-aware scheduling [2013.01]
H04L 12/875UGR5
. . . . .Delay-aware scheduling [2013.01]
H04L 12/877UGR5
. . . . .Distribution of residual bandwidth, e.g. distribution of unused bandwidth to best effort traffic [BET] [2013.01]
H04L 12/879UGR4
. . . .Single buffer operations, e.g. buffer pointers or buffer descriptors [2013.01]
H04L 12/883UGR4
. . . .Packet storage using a linked list of buffers [2013.01]
H04L 12/885UGR4
. . . .Jitter compensation buffering [2013.01]
H04L 12/891UGR3
. . .Flow control of aggregated links or flows [2013.01]
H04L 12/893UGR3
. . .Connection splitting, e.g. IP splitting [2013.01]
H04L 12/901UGR2
. .Ingress point selection by the source endpoint, e.g. Internet service provider [ISP] or point of presence [POP] selection [2013.01]
H04L 12/903UGR3
. . .Selection among a plurality of different networks [2013.01]
H04L 12/905UGR4
. . . .Dynamic network selection or re-selection, e.g. after degradation of quality [2013.01]
H04L 12/911UGR2
. .Network admission control and resource allocation, e.g. bandwidth allocation or in-call renegotiation [2013.01]
H04L 12/913UGR3
. . .Reservation actions involving intermediate nodes, e.g. resource reservation protocol [RSVP] [2013.01]
H04L 12/915UGR3
. . .Reservation actions involving several network domains, e.g. multilateral agreements or mapping of resources [2013.01]
H04L 12/917UGR3
. . .Dynamic resource allocation, e.g. in-call renegotiation requested by the user or upon changing network conditions requested by the network [2013.01]
H04L 12/919UGR4
. . . .initiated by the source endpoint [2013.01]
H04L 12/923UGR4
. . . .initiated by the network [2013.01]
H04L 12/925UGR3
. . .Reservation of resources at the destination endpoint [2013.01]
H04L 12/927UGR3
. . .Allocation of resources based on type of traffic, QoS or priority [2013.01]
H04L 12/931UGR2
. .Switch fabric architecture [2013.01]
H04L 12/933UGR3
. . .Switch core, e.g. crossbar, shared memory or shared medium [2013.01]
H04L 12/935UGR3
. . .Switch interfaces, e.g. port details [2013.01]
H04L 12/937UGR3
. . .Switch control, e.g. arbitration [2013.01]
H04L 12/939UGR3
. . .Provisions for redundant switching, e.g. using parallel switching planes [2013.01]
H04L 12/943UGR4
. . . .Transferring a complete packet or cell from each plane [2013.01]
H04L 12/945UGR4
. . . .Transferring a part of the packet or cell from each plane, e.g. bit slice [2013.01]
H04L 12/947UGR3
. . .Address processing within a device, e.g. using internal ID or tags for routing within a switch [2013.01]
H04L 12/951UGR2
. .Assembling and disassembling of packets, e.g. segmentation and reassembly [SAR] in asynchronous transfer mode [ATM] [2013.01]
H04L 12/953UGR3
. . .Packet sequencing arrangements for supporting message reassembly, e.g. packet sequence number [2013.01]
H04L 12/955UGR3
. . .Padding or de-padding, e.g. inserting or removing dummy data in or from unused packet segments [2013.01]
H04L 13/00HGRDetails of the apparatus or circuits covered by groups H04L 15/00 or H04L 17/00 [1, 2006.01]
H04L 13/02UGR1
.Details not particular to receiver or transmitter [1, 2006.01]
H04L 13/04UGR2
. .Driving mechanisms; Clutches [1, 2006.01]
H04L 13/06UGR2
. .Tape or page guiding or feeding devices [1, 2006.01]
H04L 13/08UGR2
. .Intermediate storage means [1, 2006.01]
H04L 13/10UGR2
. .Distributors [1, 2006.01]
H04L 13/12UGR3
. . .Non-mechanical distributors, e.g. relay distributors [1, 2006.01]
H04L 13/14UGR4
. . . .Electronic distributors [1, 2006.01]
H04L 13/16UGR1
.of transmitters, e.g. code-bars, code-discs [1, 2006.01]
H04L 13/18UGR1
.of receivers [1, 2006.01]
H04L 15/00HGRApparatus or local circuits for transmitting or receiving dot-and-dash codes, e.g. Morse code (teaching apparatus therefor G09B; telegraph tapping keys H01H 21/86) [1, 2006.01]
H04L 15/03UGR1
.Keys structurally combined with sound generators [2, 2006.01]
H04L 15/04UGR1
.Apparatus or circuits at the transmitting end [1, 2006.01]
H04L 15/06UGR2
. .with a restricted number of keys, e.g. separate key for each type of code element [1, 2006.01]
H04L 15/08UGR3
. . .with a single key which transmits dots in one position and dashes in a second position [1, 2006.01]
H04L 15/10UGR3
. . .combined with perforating apparatus [1, 2006.01]
H04L 15/12UGR2
. .with keyboard co-operating with code-bars [1, 2006.01]
H04L 15/14UGR3
. . .combined with perforating apparatus [1, 2006.01]
H04L 15/16UGR2
. .with keyboard co-operating with code discs [1, 2006.01]
H04L 15/18UGR2
. .Automatic transmitters, e.g. controlled by perforated tape [1, 2006.01]
H04L 15/20UGR3
. . .with optical sensing means [1, 2006.01]
H04L 15/22UGR2
. .Apparatus or circuits for sending one or a restricted number of signals, e.g. distress signals [1, 2006.01]
H04L 15/24UGR1
.Apparatus or circuits at the receiving end [1, 2006.01]
H04L 15/26UGR2
. .operating only on reception of predetermined code signals, e.g. distress signals, party-line call signals [1, 2006.01]
H04L 15/28UGR2
. .Code reproducing apparatus [1, 2006.01]
H04L 15/30UGR3
. . .Writing recorders [1, 2006.01]
H04L 15/32UGR3
. . .Perforating recorders [1, 2006.01]
H04L 15/34UGR2
. .Apparatus for recording received coded signals after translation, e.g. as type-characters [1, 2006.01]
H04L 17/00HGRApparatus or local circuits for transmitting or receiving codes wherein each character is represented by the same number of equal-length code elements, e.g. Baudot code [1, 2006.01]
H04L 17/02UGR1
.Apparatus or circuits at the transmitting end [1, 2006.01]
H04L 17/04UGR2
. .with keyboard co-operating with code-bars [1, 2006.01]
H04L 17/06UGR3
. . .Contact operating means [1, 2006.01]
H04L 17/08UGR3
. . .combined with perforating apparatus [1, 2006.01]
H04L 17/10UGR2
. .with keyboard co-operating with code-discs [1, 2006.01]
H04L 17/12UGR2
. .Automatic transmitters, e.g. controlled by perforated tape [1, 2006.01]
H04L 17/14UGR3
. . .with optical sensing means [1, 2006.01]
H04L 17/16UGR1
.Apparatus or circuits at the receiving end [1, 2006.01]
H04L 17/18UGR2
. .Code selection mechanisms [1, 2006.01]
H04L 17/20UGR2
. .using perforating recorders [1, 2006.01]
H04L 17/22UGR2
. .using mechanical translation and type-bar printing [1, 2006.01]
H04L 17/24UGR2
. .using mechanical translation and type-head printing, e.g. type-wheel, type-cylinder [1, 2006.01]
H04L 17/26UGR2
. .using aggregate motion translation [1, 2006.01]
H04L 17/28UGR2
. .using pneumatic or hydraulic translation [1, 2006.01]
H04L 17/30UGR2
. .using electric or electronic translation [1, 2006.01]
H04L 19/00HGRApparatus or local circuits for step-by-step systems [1, 2006.01]
H04L 21/00HGRApparatus or local circuits for mosaic printer telegraph systems [1, 2006.01]
H04L 21/02UGR1
.at the transmitting end [1, 2006.01]
H04L 21/04UGR1
.at the receiving end [1, 2006.01]
H04L 23/00HGRApparatus or local circuits for telegraphic systems other than those covered by groups H04L 15/00-H04L 21/00 [1, 2006.01]
H04L 23/02UGR1
.adapted for orthogonal signalling [2, 2006.01]
H04L 25/00HGRBaseband systems [1, 2006.01]
H04L 25/02UGR1
.Details [1, 2006.01]
H04L 25/03UGR2
. .Shaping networks in transmitter or receiver, e.g. adaptive shaping networks [2, 2006.01]
H04L 25/04UGR3
. . .Passive shaping networks [1, 2, 2006.01]
H04L 25/05UGR2
. .Electric or magnetic storage of signals before transmitting or retransmitting for changing the transmission rate [7, 2006.01]
H04L 25/06UGR2
. .Dc level restoring means; Bias distortion correction [1, 2006.01]
H04L 25/08UGR2
. .Modifications for reducing interference; Modifications for reducing effects due to line faults [1, 2006.01]
H04L 25/10UGR2
. .Compensating for variations in line balance [1, 2006.01]
H04L 25/12UGR2
. .Compensating for variations in line impedance [1, 2006.01]
H04L 25/14UGR2
. .Channel dividing arrangements [1, 2006.01]
H04L 25/17UGR2
. .Interpolating arrangements [4, 2006.01]
H04L 25/18UGR2
. .Arrangements for inductively generating telegraphic signals [1, 2006.01]
H04L 25/20UGR2
. .Repeater circuits; Relay circuits [1, 2006.01]
H04L 25/22UGR3
. . .Repeaters for converting two wires to four wires; Repeaters for converting single current to double current [1, 2006.01]
H04L 25/24UGR3
. . .Relay circuits using discharge tubes or semiconductor devices [1, 2006.01]
H04L 25/26UGR3
. . .Circuits with optical sensing means [1, 2006.01]
H04L 25/28UGR3
. . .Repeaters using modulation and subsequent demodulation [1, 2006.01]
H04L 25/30UGR1
.Non-synchronous systems [1, 2006.01]
H04L 25/32UGR2
. .characterised by the code employed [1, 2006.01]
H04L 25/34UGR3
. . .using three or more different amplitudes, e.g. cable code [1, 2006.01]
H04L 25/38UGR1
.Synchronous or start-stop systems, e.g. for Baudot code [1, 2006.01]
H04L 25/40UGR2
. .Transmitting circuits; Receiving circuits [1, 2006.01]
H04L 25/42UGR3
. . .using mechanical distributors [1, 2006.01]
H04L 25/44UGR3
. . .using relay distributors [1, 2006.01]
H04L 25/45UGR3
. . .using electronic distributors [2, 2006.01]
H04L 25/46UGR3
. . .using tuning forks or vibrating reeds [1, 2006.01]
H04L 25/48UGR3
. . .characterised by the code employed (H04L 25/49 takes precedence) [1, 2, 2006.01]
H04L 25/49UGR3
. . .using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels [2, 2006.01]
H04L 25/493UGR4
. . . .by transition coding, i.e. the time-position or direction of a transition being encoded before transmission [3, 2006.01]
H04L 25/497UGR4
. . . .by correlative coding, e.g. partial response coding or echo modulation coding [3, 2006.01]
H04L 25/52UGR2
. .Repeater circuits; Relay circuits [1, 2006.01]
H04L 25/54UGR3
. . .using mechanical distributors [1, 2006.01]
H04L 25/56UGR3
. . .Non-electrical regenerative repeaters [1, 2006.01]
H04L 25/58UGR3
. . .using relay distributors [1, 2006.01]
H04L 25/60UGR3
. . .Regenerative repeaters with electromagnetic switches [1, 2006.01]
H04L 25/62UGR3
. . .using tuning forks or vibrating reeds [1, 2006.01]
H04L 25/64UGR3
. . .Start-stop regenerative repeaters using discharge tubes or semiconductor devices [1, 2006.01]
H04L 25/66UGR3
. . .Synchronous repeaters using discharge tubes or semiconductor devices [1, 2006.01]
H04L 27/00HGRModulated-carrier systems [1, 2006.01]
H04L 27/01UGR1
.Equalisers [5, 2006.01]
H04L 27/02UGR1
.Amplitude-modulated carrier systems, e.g. using on/off keying; Single sideband or vestigial sideband modulation (H04L 27/32 takes precedence) [1, 2, 5, 2006.01]
H04L 27/04UGR2
. .Modulator circuits; Transmitter circuits [1, 2006.01]
H04L 27/06UGR2
. .Demodulator circuits; Receiver circuits [1, 2006.01]
H04L 27/08UGR2
. .Amplitude regulation arrangements [1, 2006.01]
H04L 27/10UGR1
.Frequency-modulated carrier systems, i.e. using frequency-shift keying (H04L 27/32 takes precedence) [1, 5, 2006.01]
H04L 27/12UGR2
. .Modulator circuits; Transmitter circuits [1, 2006.01]
H04L 27/14UGR2
. .Demodulator circuits; Receiver circuits [1, 2006.01]
H04L 27/144UGR3
. . .with demodulation using spectral properties of the received signal, e.g. by using frequency selective- or frequency sensitive elements [6, 2006.01]
H04L 27/148UGR4
. . . .using filters, including PLL-type filters [6, 2006.01]
H04L 27/152UGR4
. . . .using controlled oscillators, e.g. PLL arrangements [6, 2006.01]
H04L 27/156UGR3
. . .with demodulation using temporal properties of the received signal, e.g. detecting pulse width [6, 2006.01]
H04L 27/16UGR2
. .Frequency regulation arrangements [1, 2006.01]
H04L 27/18UGR1
.Phase-modulated carrier systems, i.e. using phase-shift keying (H04L 27/32 takes precedence) [1, 5, 2006.01]
H04L 27/20UGR2
. .Modulator circuits; Transmitter circuits [1, 2006.01]
H04L 27/22UGR2
. .Demodulator circuits; Receiver circuits [1, 2006.01]
H04L 27/227UGR3
. . .using coherent demodulation [6, 2006.01]
H04L 27/233UGR3
. . .using non-coherent demodulation [6, 2006.01]
H04L 27/24UGR2
. .Half-wave signalling systems [1, 2006.01]
H04L 27/26UGR1
.Systems using multi-frequency codes (H04L 27/32 takes precedence) [1, 5, 2006.01]
H04L 27/28UGR2
. .with simultaneous transmission of different frequencies each representing one code element [1, 2006.01]
H04L 27/30UGR2
. .wherein each code element is represented by a combination of frequencies [1, 2006.01]
H04L 27/32UGR1
.Carrier systems characterised by combinations of two or more of the types covered by groups H04L 27/02, H04L 27/10, H04L 27/18, or H04L 27/26 [5, 2006.01]
H04L 27/34UGR2
. .Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems [5, 2006.01]
H04L 27/36UGR3
. . .Modulator circuits; Transmitter circuits [5, 2006.01]
H04L 27/38UGR3
. . .Demodulator circuits; Receiver circuits [5, 2006.01]
H04L 29/00HGRArrangements, apparatus, circuits or systems, not covered by a single one of groups H04L 1/00-H04L 27/00 [5, 2006.01]
H04L 29/02UGR1
.Communication control; Communication processing (H04L 29/12, H04L 29/14 take precedence) [5, 2006.01]
H04L 29/04UGR2
. .for plural communication lines [5, 2006.01]
H04L 29/06UGR2
. .characterised by a protocol [5, 2006.01]
H04L 29/08UGR3
. . .Transmission control procedure, e.g. data link level control procedure [5, 2006.01]
H04L 29/10UGR2
. .characterised by an interface, e.g. the interface between the data link level and the physical level [5, 2006.01]
H04L 29/12UGR1
.characterised by the data terminal [5, 2006.01]
H04L 29/14UGR1
.Counter-measures to a fault [5, 2006.01]