Multiplexing - BB

MULTIPLEXING - BB
The most basic definition of multiplexing is the communication of data where the packets from several channels of varying types combine into a single channel, and therefore single medium. The primary reason that such a method is used is that a vast range of data can be sent via one route rather than the need for various channels of different configurations.

HOW IT WORKS
A device by the name of a multiplexer (often referred to as a MUX) combines all of the various signals and then send them over a single line to their destination. Once at the nodes that the data is required by a device called a demultiplexer (DEMUX) separates the data back into forms accessible by the nodes. An example image of a multiplex line can be found here (if Wikia actually let me include links).

TIME DIVISION MULTIPLEXING
Within TDM each user/node is assigned a time slot where their data will be sent. Once the time period has run out the next user's data will be checked with any data there being sent.

ADVANTAGES
-Allows for data of various mediums to be sent over a single channel

-Saves money and time due to only one channel needing to be set up and configured

-Can send different types of data over a longer distance with a single data channel

DISADVANTAGES
-The primary disadvantage of TDM has is fairly substantial. If a time slot is empty (does not contain any data to be sent) then there will be a period of time where the channel is not transmitting any data which is incredibly inefficient.

STATISTICAL TIME DIVISION MULTIPLEXING
A slight alternative to TDM, this method works in almost the same way only the when a data packet is needed to be transmitted a request will be sent for it to be sent in the next available time slot rather than the one preassigned with the node.

ADVANTAGES
-Data can be sent far faster than with standard TDM as data does not have to wait for its node's assigned time slot

-More efficient as there will only be empty time slots if no data packets need to be transmitted