# Call-second

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> Markdown URL: https://mediated.wiki/source/Call-second.md
> Source: https://en.wikipedia.org/wiki/Call-second
> Source revision: 1242417060
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{no footnotes|date=March 2013}}

In [telecommunications](/source/telecommunications), a '''call-second''' is a unit used to measure [communication](/source/communication)s [traffic](/source/traffic) density, equivalent to one call with a duration of one second. 

Traffic is measured independent of users. For example, one [user](/source/User_(telecommunications)) making two 75-second calls is equivalent to two users each making one 75-second call, as each case produces 150 call-seconds of traffic. 

A CCS (centacall-second) is often used to describe 100 call-seconds, so 3600 call-seconds = 36 CCS = 1 call-hour. 

In a communication network, a trunk (link) can carry numerous concurrent calls by means of multiplexing. Hence a particular number of call-seconds can be carried in infinitely many ways as calls are established and cleared over time.  For example, one call-hour could be one call for an hour or two (possibly concurrent) calls for half an hour each. Call-seconds give a measure of the average number of concurrent calls.

[Offered load](/source/Offered_load) is defined as the traffic density per unit time, measured in [erlangs](/source/Erlang_(unit)). An erlang is defined as one call-hour per hour, or 3,600 call-seconds per hour.

Hence, if one CCS is measured over a one-hour period, the offered load is 1/36 erlangs.

==References==
*{{FS1037C MS188}}

Category:Units of measurement
Category:Telecommunications

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Adapted from the Wikipedia article [Call-second](https://en.wikipedia.org/wiki/Call-second) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Call-second?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.