In
telecommunications
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha ...
, a transverse redundancy check (TRC) or vertical redundancy check is a
redundancy check
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communic ...
for synchronized parallel
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented a ...
s applied once per bit time, across the bit streams. This requires additional parallel channels for the check bit or bits.
The term usually applies to a single
parity bit
A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes) ...
, although it could also be used to refer to a larger
Hamming code
In computer science and telecommunication, Hamming codes are a family of linear error-correcting codes. Hamming codes can detect one-bit and two-bit errors, or correct one-bit errors without detection of uncorrected errors. By contrast, the s ...
.
The adjective "transverse" is most often used when it is used in combination with additional error control coding, such as a
longitudinal redundancy check
In telecommunication, a longitudinal redundancy check (LRC), or horizontal redundancy check, is a form of redundancy check that is applied independently to each of a parallel group of bit streams. The data must be divided into transmission bloc ...
. Although parity alone can only detect and not correct errors, it can be part of a system for correcting errors.
An example of a TRC is the parity written to the 9th track of a
9-track tape.
References
* {{FS1037C MS188
Error detection and correction