D4 framing standard
Encyclopedia
In telecommunication
, a D-4 is a framing standard
for traditional time-division multiplexing
, which standard describes user
channels multiplexed onto a trunk
that has been segmented (framed) into 24 bytes of 8 bits each.
Note: The multiplexing function is performed in the D-4 framing structure by interleaving
bits of consecutive bytes as they are presented from individual circuits into each D-4 frame.
Within Telecommunications operations, a D4 Bank also refers to a type of multiplexer
which mux's 24 DS0 signals into a single DS1
.
Source: from Federal Standard 1037C
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, a D-4 is a framing standard
Standardization
Standardization is the process of developing and implementing technical standards.The goals of standardization can be to help with independence of single suppliers , compatibility, interoperability, safety, repeatability, or quality....
for traditional time-division multiplexing
Time-division multiplexing
Time-division multiplexing is a type of digital multiplexing in which two or more bit streams or signals are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent...
, which standard describes user
User (telecommunications)
In telecommunications, a user is a person, organization, or other entity that employs the services provided by a telecommunication system, or by an information processing system, for transfer of information....
channels multiplexed onto a trunk
Trunking
In modern communications, trunking is a concept by which a communications system can provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually. This is analogous to the structure of a tree with one trunk and many branches. Examples of...
that has been segmented (framed) into 24 bytes of 8 bits each.
Note: The multiplexing function is performed in the D-4 framing structure by interleaving
Interleaving
In computer science and telecommunication, interleaving is a way to arrange data in a non-contiguous way to increase performance.It is typically used:* In error-correction coding, particularly within data transmission, disk storage, and computer memory....
bits of consecutive bytes as they are presented from individual circuits into each D-4 frame.
Within Telecommunications operations, a D4 Bank also refers to a type of multiplexer
Multiplexer
In electronics, a multiplexer is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2n inputs has n select lines, which are used to select which input line to send to the output...
which mux's 24 DS0 signals into a single DS1
Digital Signal 1
Digital signal 1 is a T-carrier signaling scheme devised by Bell Labs. DS1 is a widely used standard in telecommunications in North America and Japan to transmit voice and data between devices. E1 is used in place of T1 outside North America, Japan, and South Korea...
.
Source: from Federal Standard 1037C
Federal Standard 1037C
Federal Standard 1037C, titled Telecommunications: Glossary of Telecommunication Terms is a United States Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended....