Here is another common Data Transmission scenorio - a computer sending data to a printer.
Different systems could use simplex, duplex or half-duplex data transmission. However, another interesting observation here is that the data is traveling along a single wire, each bit following the other. This is known as serial transmisson.
Because the bits arrive in order, it is straightforward to process the data.
Notice that the data can't be fully processed until the last bit is received.
This system uses parallel data transmission. More than one wire is used to transfer the data simultaneously. If there are 8 wires, we can transfer a full byte of information at one time.
It looks like all of the information arrives at the same time. So, this should be a faster data transmission system. However, in reality, the longer the connection, the more likely that one or more of the bits will arrive late or that there will be interference between the wires, which are close together.
So parallel data transmission is suitable for short distances.
Also, because parallel data transmission requires more wires, it is more expensive than serial transmission. For this reason, parallel data transmission is often used over short distances eg connecting a computer to a printer.
| transmission type | application |
|---|---|
| parallel | modern printers use this method |
| serial | connecting your computer to a modem |