erlang

Erlang

(1) A unit of measurement of telephone traffic. It is equal to one hour of conversation (3,600 seconds or 36 CCS). Named after the Danish mathematician Agner Krarup Erlang, it also specifies the approximate number of trunks in use; for example, if the traffic in a call center is 8.5 Erlangs in one hour, more than 8 trunks were used in that hour. See CCS.

(2) An open source programming language specialized for concurrent processing (multiprocessing) on Unix-based and Windows computers. Originally developed by Ericsson and named after A. K. Erlang (see definition #1 above) as well as "Ericsson Language," Erlang makes programming threads easier to write than in traditional languages. Developed in the late 1980s, Erlang was modeled after concurrent languages such as Ada and Modula and functional languages such as ML and Miranda. For more information, visit www.erlang.org and www.erlang.se. See thread and multithreading.

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erlang [′er‚läŋ]

(communications)

A unit of communication traffic load, equal to the traffic load whose calls, if placed end to end, will keep one path continuously occupied.

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1.	(person)	Erlang - Agner Krarup Erlang. (The other senses were named after him).
2.	(language)	Erlang - A concurrent functional language for large industrial real-time systems by Armstrong, Williams and Virding of Ellemtel, Sweden. Erlang is untyped. It has pattern matching syntax, recursion equations, explicit concurrency, asynchronous message passing and is relatively free from side-effects. It supports transparent cross-platform distribution. It has primitives for detecting run-time errors, real-time garbage collection, modules, dynamic code replacement (change code in a continuously running real-time system) and a foreign language interface. An unsupported free version is available (subject to a non-commercial licence). Commercial versions with support are available from Erlang Systems AB. An interpreter in SICStus Prolog and compilers in C and Erlang are available for several Unix platforms. Open Telecom Platform (OTP) is a set of libraries and tools. Commercial version - sales, support, training, consultants. Open-source version - downloads, user-contributed software, mailing lists. Training and consulting. E-mail: <erlang@erix.ericsson.se>. [Erlang - "Concurrent Programming in Erlang", J. Armstrong, M. & Williams R. Virding, Prentice Hall, 1993. ISBN 13-285792-8.]
3.	(unit)	Erlang - 36 CCS per hour, or 1 call-second per second. Erlang is a unit without dimension, accepted internationally for measuring the traffic intensity. This unit is defined as the aggregate of continuous occupation of a channel for one hour (3600 seconds). An intensity of one Erlang means the channel is continuously occupied.