TECHNOLOGY OPTIONS
The multiplexer is a device that accepts multiple electronic transmission signals and combines them into one high-speed transmission. A multiplexer, also known as a mux, is often used to allow remote terminals to communicate with front-end processor ports over a single circuit.

Multiplexing is a method that allows a single communications circuit to take the place of several parallel communications circuits. Multiplexers are points in the network where different traffics merge or segregate ‘from core to access’ and ‘from access to core.’

This allows multiple data streams to be carried from one place to another over one physical link, which saves cost. At the receiving end of the data link, a complementary demultiplexer or demux is required to break the high data-rate stream back down into the original lower rate streams. It is usual to combine a multiplexer and a demultiplexer together into one piece of equipment and simply refer to the whole thing as a multiplexer. Both pieces of equipment are needed at both ends of a transmission link because most communications systems transmit in both direction.

l Inverse Multiplexer: An inverse multiplexer or demultiplexer allows a data stream to be broken into multiple lower data-rate-communications links. This provides an end-to-end connection of three times the data rate available on each of the low-rate data links.

l Digital Subscriber Line Access Multiplexer (DSLAM): A digital subscriber line access multiplexer (DSLAM) is the multiplexer located in the telephone company’s exchange that provides consumers access to DSL services over twisted pair copper cabling.

The device separates the voice and data components from the subscriber lines and aggregates the data for sending over the telephone network. The DSLAM usually aggregates lines at a contention ratio of 50:1 or 20:1.

Alternatively, a DSLAM multiplexes the signal output by a main distribution frame (MDF), which belong to different users, into a stream which can be processed by an asynchronous transfer mode (ATM) network.