H
SECTION H — ELECTRICITY
 H04
ELECTRIC COMMUNICATION TECHNIQUE
 H04

Note(s)

This class covers electrical communication systems with propagation paths employing light (optical communication), infra-red, ultrasonic, sonic, or infrasonic waves.

 H04Q
SELECTING (switches, relays, selectors H01H; electronic switches H03K 17/00)
 H04Q

Note(s)

  1. This subclass covers:
    • methods, circuits, or apparatus for establishing selectively a connection between a desired number of stations (normally two), or between a main station and a desired number of substations (normally one) for the purpose of transferring information via this connection after it has been established;
    • selective calling arrangements over connections already established. In either case, the connection may be by means of electric conductors or electromagnetic waves.
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "subscriber" is ageneral term for terminal equipment, e.g. telephone for public use;
    • "substation" means a subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber;
    • "satellite" is a kind of exchange the operation of which depends upon control signals received from a supervisory exchange;
    • "switching centres" includes exchanges and satellites.
 H04Q 1/00
Details of selecting apparatus or arrangements (details of selector switches H01H 63/00)
 H04Q 1/02
·  Constructional details
 H04Q 1/04
·  ·  Frames or mounting racks for selector switches; Accessories therefor, e.g. frame cover
 H04Q 1/06
·  ·  Cable ducts or mountings specially adapted for exchange installations (in general H02G)
 H04Q 1/08
·  ·  Frames or mounting racks for relays; Accessories therefor
 H04Q 1/10
·  ·  Exchange station construction
 H04Q 1/12
·  ·  Arrangements of multiple bars with or without pivotable frames
 H04Q 1/14
·  ·  Distribution frames
 H04Q 1/16
·  ·  Wiring arrangements for selector switches or relays in frames
 H04Q 1/18
·  Electrical details
 H04Q 1/20
·  ·  Testing circuits or apparatus; Circuits or apparatus for detecting, indicating, or signalling faults or troubles
 H04Q 1/22
·  ·  ·  Automatic arrangements
 H04Q 1/24
·  ·  ·  ·  for connection devices
 H04Q 1/26
·  ·  ·  ·  for signalling trouble in unoccupied sub-exchanges
 H04Q 1/28
·  ·  Current-supply circuits or arrangements for selection equipment at exchanges
 H04Q 1/30
·  ·  Signalling arrangements; Manipulation of signalling currents (multiplex systems providing for calling or supervisory signals H04J 1/14, H04J 3/12; telephone substation equipment H04M 1/00)
 H04Q 1/32
·  ·  ·  using trains of dc pulses (H04Q 1/39 takes precedence)  [3]
 H04Q 1/34
·  ·  ·  ·  Impulse regenerators with mechanical or other non-electrical marking arrangements
 H04Q 1/36
·  ·  ·  ·  Pulse-correcting arrangements, e.g. for reducing effects due to interference
 H04Q 1/38
·  ·  ·  using combinations of direct currents of different amplitudes or polarities over line conductors or combination of line conductors
 H04Q 1/39
·  ·  ·  using coded pulse groups  [3]
 H04Q 1/40
·  ·  ·  whereby duration of pulse or interval between two pulses is variable
 H04Q 1/42
·  ·  ·  ·  involving the position of a pulse in a cycle
 H04Q 1/44
·  ·  ·  using ac (H04Q 1/50 takes precedence)  [3]
 H04Q 1/442
·  ·  ·  ·  with out-of-voice band signalling frequencies  [3]
 H04Q 1/444
·  ·  ·  ·  with voice-band signalling frequencies  [3]
 H04Q 1/446
·  ·  ·  ·  ·  using one signalling frequency (H04Q 1/46 take precedence)  [3]
 H04Q 1/448
·  ·  ·  ·  ·  ·  with conversion of a single frequency signal into a digital signal  [3]
 H04Q 1/45
·  ·  ·  ·  ·  using multi-frequency signalling (H04Q 1/46 takes precedence)  [3]
 H04Q 1/453
·  ·  ·  ·  ·  ·  in which m-out-of-n signalling frequencies are transmitted  [3]
 H04Q 1/457
·  ·  ·  ·  ·  ·  with conversion of multi-frequency signals into digital signals  [3]
 H04Q 1/46
·  ·  ·  ·  ·  comprising means for distinguishing between a signalling current of predetermined frequency and a complex current containing that frequency, e.g. speech current  [3]
 H04Q 1/48
·  ·  ·  Induced-current signalling arrangements
 H04Q 1/50
·  ·  ·  Conversion between different kinds of signals
 H04Q 1/54
·  ·  Amplifier switched-on automatically in dependence on automatically selected lines
 H04Q 1/56
·  ·  Balancing circuitry switched-on automatically in dependence on automatically selected lines
 H04Q 3/00
Selecting arrangements (H04Q 5/00-H04Q 11/00 take precedence)
 H04Q 3/02
·  Circuit arrangements for selectors responsive to a permutation code
 H04Q 3/04
·  Circuit arrangements for receivers of routing digits
 H04Q 3/06
·  ·  for group or trunk group selectors
 H04Q 3/08
·  ·  for local or long-distance selectors
 H04Q 3/10
·  ·  for PBX selectors, i.e. private branche exchange selectors
 H04Q 3/12
·  ·  for line selectors providing transfer of routing digits
 H04Q 3/14
·  ·  for two-way operation selectors
 H04Q 3/16
·  ·  for marking-switches
 H04Q 3/18
·  Circuit arrangements for first stage of hunting switching
 H04Q 3/20
·  ·  for preselectors
 H04Q 3/22
·  ·  ·  comprising common calling and disconnecting circuit
 H04Q 3/24
·  ·  for line finders
 H04Q 3/26
·  ·  ·  comprising common calling and disconnecting circuit
 H04Q 3/28
·  ·  ·  comprising main groups and subgroups
 H04Q 3/30
·  ·  Selector finders, i.e. allotters
 H04Q 3/32
·  Circuit arrangements for second or subsequent stages of hunting switching  [2]
 H04Q 3/34
·  ·  for the second preselection stage
 H04Q 3/36
·  ·  for the second line-finder stage
 H04Q 3/38
·  ·  for stages after the group-selector stage
 H04Q 3/40
·  ·  for stages after the line selector, e.g. for extension selector
 H04Q 3/42
·  Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker
 H04Q 3/44
·  ·  using revertive control
 H04Q 3/46
·  ·  using signals other than revertive impulses
 H04Q 3/47
·  ·  using translators
 H04Q 3/48
·  ·  using markers
 H04Q 3/49
·  ·  ·  for end-to-end marking
 H04Q 3/495
·  ·  ·  for routing connecting paths
 H04Q 3/52
·  ·  using static devices in switching stages, e.g. electronic switching arrangements  [2]
 H04Q 3/54
·  ·  in which the logic circuitry controlling the exchange is centralised
 H04Q 3/545
·  ·  ·  using a stored programme  [4]
 H04Q 3/55
·  ·  ·  using wired logic circuitry  [4]
 H04Q 3/555
·  ·  ·  ·  being comprised by electro-magnetic devices  [4]
 H04Q 3/56
·  ·  in which the control signals are multiplexed  [2]
 H04Q 3/58
·  Arrangements providing connection between main exchange and sub-exchange or satellite
 H04Q 3/60
·  ·  for connecting to satellites or concentrators which connect one or more exchange lines with a group of local lines
 H04Q 3/62
·  ·  for connecting to private branch exchanges
 H04Q 3/64
·  Distributing or queueing
 H04Q 3/66
·  ·  Traffic distributors
 H04Q 3/68
·  ·  Grouping or interlacing selector groups or stages
 H04Q 3/70
·  Identification of class of calling subscriber
 H04Q 3/72
·  Finding out and indicating number of calling subscriber
 H04Q 3/74
·  ·  Identification of subscriber calling from a party-line
 H04Q 3/76
·  Translation from the called subscriber's number to the outgoing or incoming control information  [4]
 H04Q 3/78
·  Temporary storage of information of calling or called subscriber (intermediate storage means for telegraphic communication H04L 13/08)  [4]
 H04Q 5/00
Selecting arrangements wherein two or more subscriber stations are connected by the same line to the exchange
 H04Q 5/02
·  with direct connection for all subscribers, i.e. party-line system (H04Q 5/24 takes precedence)
 H04Q 5/04
·  ·  Signalling by currents in one or other or both line wires or additional wires
 H04Q 5/06
·  ·  Signalling by amplitude or polarity of dc
 H04Q 5/08
·  ·  Signalling by continuous ac
 H04Q 5/10
·  ·  ·  using single frequencies for different subscribers
 H04Q 5/12
·  ·  ·  using combinations of frequencies
 H04Q 5/14
·  ·  Signalling by pulses
 H04Q 5/16
·  ·  ·  by predetermined number of pulses
 H04Q 5/18
·  with indirect connection, i.e. through subordinate switching centre
 H04Q 5/20
·  ·  the subordinate centre permitting interconnection of subscribers connected thereto
 H04Q 5/22
·  ·  the subordinate centre not permitting interconnection of subscribers connected thereto
 H04Q 5/24
·  for two-party-line systems
 H04Q 7/00
Selecting arrangements to which subscribers are connected via radio links or inductive links
 H04Q 7/02
·  for subscribers using radio or inductive link only
 H04Q 7/04
·  with possibility of connection to and from line exchanges
 H04Q 9/00
Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom
 H04Q 9/02
·  Automatically-operated arrangements
 H04Q 9/04
·  Arrangements for synchronous operation
 H04Q 9/06
·  Calling by using amplitude or polarity of dc
 H04Q 9/08
·  Calling by using continuous ac
 H04Q 9/10
·  ·  using single different frequencies
 H04Q 9/12
·  ·  using combinations of frequencies
 H04Q 9/14
·  Calling by using pulses
 H04Q 9/16
·  ·  by predetermined number of pulses
 H04Q 11/00
Selecting arrangements for multiplex systems (multiplex systems H04J)
 H04Q 11/02
·  for frequency-division multiplexing
 H04Q 11/04
·  for time-division multiplexing