A unit used to describe traffic density in telephony, named for A. K. Erlang (1878-1929), a Danish mathematician. It has several related senses:
A unit of traffic intensity: the average number of simultaneous connections observed during a measurement period.
ANSI/IEEE Standard 312-1977.
Standard Definitions of Terms for Communication Switching.
A unit of message loading, used to describe usage of leased facilities. The number of call-seconds divided by 3,600, or in other words, if 1 circuit was in continuous use for 1 hour 1 erlang of use would have occurred.
IEEE Standard 599-1983.
Standard Glossary of Power Systems Data Transmission and Related Channel Terminology.
A collection of interactive calculators for determining erlangs: www.erlang.com/calculator/
A brief biography of Erlang: http://pass.maths.org.uk/issue2/erlang/index.html
Copyright © 2000, 2002 Sizes, Inc. All rights reserved.
Last revised: 4 May 2006.