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19-554: The ISQ symbols for the bit and byte are bit and B , respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet . The abbreviation bps is often used to mean bit/s, so that when a 1 Mbps connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s ( megabyte per second ), or about 0.1192 MiB/s ( mebibyte per second ). The Institute of Electrical and Electronics Engineers (IEEE) uses

38-512: A dimensionless quantity (a term that is still commonly used); all its dimensional exponents are zero and its dimension symbol is 1 {\displaystyle 1} . Such a quantity can be regarded as a derived quantity in the form of the ratio of two quantities of the same dimension. The named dimensionless units " radian " (rad) and " steradian " (sr) are acceptable for distinguishing dimensionless quantities of different kind, respectively plane angle and solid angle . The level of

57-433: A given system of physical quantities is a subset of those quantities, where no base quantity can be expressed in terms of the others, but where every quantity in the system can be expressed in terms of the base quantities. Within this constraint, the set of base quantities is chosen by convention. There are seven ISQ base quantities . The symbols for them, as for other quantities, are written in italics. The dimension of

76-457: A physical quantity does not include magnitude or units. The conventional symbolic representation of the dimension of a base quantity is a single upper-case letter in roman (upright) sans-serif type. A derived quantity is a quantity in a system of quantities that is defined in terms of only the base quantities of that system. The ISQ defines many derived quantities and corresponding derived units . The conventional symbolic representation of

95-493: A quantity is defined as the logarithm of the ratio of the quantity with a stated reference value of that quantity. Within the ISQ it is differently defined for a root-power quantity (also known by the deprecated term field quantity ) and for a power quantity. It is not defined for ratios of quantities of other kinds. Within the ISQ, all levels are treated as derived quantities of dimension 1. Several units for levels are defined by

114-590: A quantity. The name is derived from the first two letters of the original SI prefixes followed by bi (short for binary ). It also clarifies that the SI prefixes are used only to mean powers of 10 and never powers of 2. These units are often used in a manner inconsistent with the IEC standard. Kilobit per second (symbol kbit/s or kb/s , often abbreviated "kbps") is a unit of data transfer rate equal to: Megabit per second (symbol Mbit/s or Mb/s , often abbreviated "Mbps")

133-658: Is a standard system of quantities used in physics and in modern science in general. It includes basic quantities such as length and mass and the relationships between those quantities. This system underlies the International System of Units (SI) but does not itself determine the units of measurement used for the quantities. The system is formally described in a multi-part ISO standard ISO/IEC 80000 (which also defines many other quantities used in science and technology), first completed in 2009 and subsequently revised and expanded. The base quantities of

152-428: Is a unit of data transfer rate equal to: Gigabit per second (symbol Gbit/s or Gb/s , often abbreviated "Gbps") is a unit of data transfer rate equal to: Terabit per second (symbol Tbit/s or Tb/s , sometimes abbreviated "Tbps") is a unit of data transfer rate equal to: These units are often not used in the suggested ways; see § Variations . kilobyte per second ( kB/s ) (sometimes abbreviated "kBps")

171-454: Is a unit of data transfer rate equal to: megabyte per second ( MB/s ) (can be abbreviated as MBps) is a unit of data transfer rate equal to: gigabyte per second ( GB/s ) (can be abbreviated as GBps) is a unit of data transfer rate equal to: terabyte per second ( TB/s ) (can be abbreviated as TBps) is a unit of data transfer rate equal to: International System of Quantities The International System of Quantities ( ISQ )

190-527: Is one of the three main kinds of historical type , alongside blackletter and italic . Sometimes called normal , it is distinct from these two for its upright style (relative to the calligraphy-inspired italic) and its simplicity (relative to blackletter). During the early Renaissance , roman (in the form of Antiqua ) and italic type were used separately. Today, roman and italic type are mixed, and most typefaces are composed of both an upright roman style and an associated italic or oblique style. Roman type

209-474: The kilobyte in its binary sense . In the context of data rates, however, typically only decimal prefixes are used, and they have their standard SI interpretation. In 1999, the IEC published Amendment 2 to " IEC 60027-2 : Letter symbols to be used in electrical technology – Part 2: Telecommunications and electronics". This standard, approved in 1998, introduced the prefixes kibi-, mebi-, gibi-, tebi-, pebi-, and exbi- to be used in specifying binary multiples of

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228-555: The ISQ. ISO/IEC 80000 defines physical quantities that are measured with the SI units and also includes many other quantities in modern science and technology. The name "International System of Quantities" is used by the General Conference on Weights and Measures (CGPM) to describe the system of quantities that underlie the International System of Units . Roman (typeface) In Latin script typography , roman

247-402: The SI and classified as "non-SI units accepted for use with the SI units". An example of level is sound pressure level , with the unit of decibel . Units of logarithmic frequency ratio include the octave , corresponding to a factor of 2 in frequency (precisely) and the decade , corresponding to a factor 10. The ISQ recognizes another logarithmic quantity, information entropy , for which

266-536: The coherent unit is the natural unit of information (symbol nat). The system is formally described in a multi-part ISO standard ISO/IEC 80000 , first completed in 2009 but subsequently revised and expanded, which replaced standards published in 1992, ISO 31 and ISO 1000 . Working jointly, ISO and IEC have formalized parts of the ISQ by giving information and definitions concerning quantities, systems of quantities, units, quantity and unit symbols, and coherent unit systems, with particular reference to

285-558: The dimension of a derived quantity is the product of powers of the dimensions of the base quantities according to the definition of the derived quantity. The dimension of a quantity is denoted by L a M b T c I d Θ e N f J g {\displaystyle {\mathsf {L}}^{a}{\mathsf {M}}^{b}{\mathsf {T}}^{c}{\mathsf {I}}^{d}{\mathsf {\Theta }}^{e}{\mathsf {N}}^{f}{\mathsf {J}}^{g}} , where

304-417: The dimensional exponents are positive, negative, or zero. The dimension symbol may be omitted if its exponent is zero. For example, in the ISQ, the quantity dimension of velocity is denoted L T − 1 {\displaystyle {\mathsf {LT}}^{-1}} . The following table lists some quantities defined by the ISQ. A quantity of dimension one is historically known as

323-404: The modern characteristics of Roman type, for instance an 'h' with a nearly straight right leg, serifs on the outside of the capital 'M' and 'N', and 'e' with level cross stroke, by the 1530s. Popular roman typefaces include Bembo , Baskerville , Caslon , Jenson , Times New Roman and Garamond . The name roman is customarily applied uncapitalized distinguishing early Italian typefaces of

342-580: The symbol b for bit. In both the SI and ISQ, the prefix k stands for kilo , meaning 1000, while Ki is the symbol for the binary prefix kibi- , meaning 1024. The binary prefixes were introduced in 1998 by the International Electrotechnical Commission (IEC) and in IEEE 1541-2002 which was reaffirmed on 27 March 2008. The letter K is often used as a non-standard abbreviation for 1,024, especially in "KB" to mean KiB,

361-532: Was modelled from a European scribal manuscript style of the 15th century, based on the pairing of inscriptional capitals used in ancient Rome with Carolingian minuscules . Early roman typefaces show a variety of designs, for instance resembling what would now be considered blackletter. Printers and typefounders such as Nicolas Jenson and Aldus Manutius in Venice and later Robert Estienne in France codified

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