IEC 80000-13

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IEC 80000-13:2008 is an international standard that defines quantities and units used in information science, and specifies names and symbols for these quantities and units. The standard is published by the International Electrotechnical Commission (IEC) and is part of the group of standards called ISO/IEC 80000, published jointly by the IEC and the International Organization for Standardization (ISO).[1]

It is divided into the following chapters:

  1. Scope
  2. Normative references
  3. Names, definitions and symbols
  4. Prefixes for binary multiples

Names, definitions and symbols[edit]

Quantities defined by the standard include

  • traffic intensity (symbol A): number of simultaneously busy resources in a particular pool of resources
  • traffic offered intensity (symbol A0): traffic intensity ... of the traffic that would have been generated by the users of a pool of resources if their use had not been limited by the size of the pool
  • traffic carried intensity (symbol Y): traffic intensity ... of the traffic served by a particular pool of resources
  • mean queue length (symbol L): time average of queue length
  • loss probability (symbol B): probability for losing a call attempt
  • weighting probability (symbol W): probability for waiting for a resource
  • call intensity (symbol λ): number of call attempts over a specified time interval divided by the duration (ISO 80000-3 ...) of this interval
  • completed call intensity (symbol μ): call intensity ... for the call attempts that result in the transmission of an answer signal

The Standard also includes definitions for units relating to information technology, such as the erlang (symbol E), bit (bit), octet (o), byte (B), baud (Bd), shannon (Sh), hartley (Hart) and the natural unit of information (nat).

Prefixes for binary multiples[edit]

Clause 4 of the Standard defines standard binary prefixes used to denote powers of 1024 from 10241 (kibi) to 10248 (yobi).

See also[edit]