Line signaling

Line signaling

Line signaling is a class of telecommunications signaling protocols. Line signaling is responsible for off-hook, ringing signal, answer, ground start, on-hook unidirectional supervision messaging in each direction from calling party to called party and vice versa. After an off-hook, line signaling initiates register signaling to accomplish the exchange of telephone numbers of called party and in more modern line-signaling protocols, the calling party as well. While register signaling occurs, line signaling remains quiescent unless the calling party goes on-hook or an abnormal cessation of the call occurs, such as due to equipment malfunction or shutdown or due to network outage upstream in that call-attempt's series of spanned trunks.

Line signaling can be conveyed in a single DS0 channel of a trunk. In modern PCM telecommunications, line signaling is represented by the ABCD bits in DS0 #16 of an E1 or a selected DS0 within a T1.

Line signaling can also be conveyed within the channels being supervised, as in the original T1 scheme which used one out of every eight bits for supervision, or with robbed bits of a superframe format, or as in-band signaling, e.g. as in L1 signaling where 2280 Hz tone pulses are used.

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Signaling (telecommunications) — In telecommunication, signaling (signalling in British spelling) has the following meanings: the use of signals for controlling communications the information exchange concerning the establishment and control of a telecommunication circuit and… …   Wikipedia

  • Signaling System No. 5 — CCITT5 [ REC Q.140 Q.180/en ITU T Recommendation Q.140 Q.180] Specifications of Signalling System No. 5] was a multi frequency (MF) telephone signalling system in use from the 1970s for International Direct Distance… …   Wikipedia

  • Line 10, Beijing Subway — Beijing Line type = Rapid transit system = Beijing Subway status = Operational locale = Beijing, China start = Bagou end = Jinsong stations = 22 routes = ridership = opened = July 19, 2008 closed = owner = operator = Beijing Mass Transit Railway… …   Wikipedia

  • Line code — An example of coding a binary signal using rectangular pulse amplitude modulation with polar non return to zero code …   Wikipedia

  • Line Printing Terminal — IEEE 1284 Druckerkabel (Typ AB) Der veraltende IEEE 1284 Standard definiert eine parallele Schnittstelle zur bidirektionalen Übertragung von Daten zwischen PCs und unterschiedlichen Peripheriegeräten (Drucker, Fax, Scanner, Laufwerke etc.). Der… …   Deutsch Wikipedia

  • In-band signaling — In telecommunications, in band signaling is the sending of metadata and control information in the same band, on the same channel, as used for data.TelephoneFor example, when dialing a modern telephone, the telephone number is encoded and… …   Wikipedia

  • Single-frequency signaling — (SF) is line signaling (in telephony) in which dial pulses or supervisory signals are conveyed by a single voice frequency tone in each direction. SF and similar systems were used in 20th century carrier systems.An SF signaling unit converts DC… …   Wikipedia

  • off-hook signaling —    1. With regard to line signaling, the condition indicating that a station is being used (line loop closed).    2. With regard to trunk signaling, off hook signaling in the forward direction exists after seizure of the trunk by the switching… …   IT glossary of terms, acronyms and abbreviations

  • on-hook signaling —    1. With regard to line signaling, the condition indicating that a station is idle (line loop open).    2. With regard to trunk signaling, on hook signaling in the forward direction exists when the trunk is not being used. On hook signaling in… …   IT glossary of terms, acronyms and abbreviations

  • E and M signaling — E M is a type of supervisory line signaling that uses separate leads, called the E lead and M lead, traditionally used in the North American telecommunications industry. There are different E M standards, with 8, 6, 4 and even 2 wires.Number of… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.