For another meaning of the term "traffic engineering", please see transport traffic engineering.
Traffic engineering uses statistical techniques such as queuing theory to predict and engineer the behaviour of telecommunications networks such as telephone networks or the Internet.
The field was created by the work of A. K. Erlang in whose honour the unit of telecommunication traffic intensity, the Erlang is named.
His Erlang distributions are still in common use in telephone traffic engineering.
The crucial observation in traffic engineering is that in large systems the law of large numbers can be used to make the aggregate properties of a system over a long period of time much more predictable than the behaviour of individual parts of the system.
The queueing theory originally developed for circuit-switched networks is applicable to packet-switched networks.
The most notable difference between these sub-fields is that packet-switched data traffic is self-similar. This is a consequence of the calls being between computers, and not people.
See also