Off-hook - Citizendia

In telephony, the term off-hook has the following meanings:

The condition that exists when a telephone or other user instrument is in use, i. In Telecommunication, telephony (təˈlɛfəni or teh-LEH-fuh-nee encompasses the general use of equipment to provide voice communication over distances specifically Basic principle A traditional landline telephone system also known as "plain old telephone service" (POTS, commonly handles both signaling and audio information In Telecommunications, a user is a person organization or other entity that employs the services provided by a Telecommunication system or by an Information e. , during dialing or communicating. Note: off-hook originally referred to the condition that prevailed when telephones had a separate earpiece (i. Headphones (also known as earphones, earbuds, stereophones, headsets) are a pair of small Loudspeakers or less commonly a single e. , receiver), which hung from its switchhook until the user wished to activate it. The weight of the receiver no longer depresses the spring loaded switchhook, thereby connecting the instrument to the telephone line. A telephone line or telephone circuit (or just line or circuit within the Industry) is a single-user circuit on a Telephone
One of two possible signaling states, such as tone or no tone and ground connection versus battery connection. In Telecommunication, signalling (UK spelling or signaling (US spelling has the following meanings The use of signals for controlling communications An electrical connection between discrete points allows the flow of Electrons ( Electric current) Note that if off-hook pertains to one state, on-hook pertains to the other. In Telephony, the term on-hook has the following meanings The condition that exists when a Telephone or other user instrument is not
The active state, i. e. , a closed loop of a subscriber line or PBX user loop. In Telephony, the local loop (also referred to as a subscriber line) is the physical link or circuit that connects from the Demarcation point of the
An operating state of a communications link in which data transmission is enabled either for (a) voice or data communications or (b) network signaling. Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's In Telecommunications transmission is the process of sending propagating and receiving an analogue or digital information signal over a physical point-to-point or A telecommunications network is a network of Telecommunications links and nodes arranged so that messages may be passed from one part of the network to another over In Telecommunication, signalling (UK spelling or signaling (US spelling has the following meanings The use of signals for controlling communications

Source: from Federal Standard 1037C and from MIL-STD-188

On an ordinary two-wire telephone line, off-hook status is communicated to the telephone exchange by a resistance short across the pair. Federal Standard 1037C, entitled Telecommunications Glossary of Telecommunication Terms is a United States Federal Standard issued by the General Services Administration MIL-STD-188 is a series of US military standards relating to Telecommunications Purpose Faced with “past technical deficiencies in telecommunications In the field of Telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls When an off-hook condition persists without dialing, for example because the handset has fallen off or the cable has been flooded, it is treated as a permanent loop or permanent signal. Permanent Signal (PS in US Telephony jargon or Permanent Loop in British usage is a condition in which a POTS line is Off-hook without connection

The act of going off-hook is also referred to as seizing the line or channel.

See also