# 2.2 Data transmission fundamentals

## How quickly can information flow?

#### Having covered the 'non-engineering' factors affecting data transmission in Section 2.1, we now focus on establishing the ground rules governing effective engineering design of a digital communications link. To do this, it is helpful to consider the question: 'What limits how quickly information can be sent over any given channel?'
#### Given a requirement to send digital information from a source (for example, a computer) to a destination (for example, a printer), let us consider how quickly we can transfer 1000000 bits of information over a communications link:

#### More than 1 second? | #### More than 1 millisecond? | #### Instantaneously?

#### By moving on to look at some possible transmission methods we will identify the critical limiting factors and hence determine the answer.