AQA A2 Computing 6.1 Communications Methods

Question 1

Data transmission

Answer 1

Movement of data from one place to another.

Question 2

Serial data transmission

Answer 2

Single bits are sent one after another along a single wire.

Question 3

Parallel data transmission

Answer 3

Bits are sent down several wires simultaneously.

Question 4

Baud rate

Answer 4

The rate at which signals on a line may change.

Question 5

1 baud

Answer 5

One signal change per second.

Question 6

Bit rate

Answer 6

The number of bits transmitted per second.

Question 7

Bandwidth

Answer 7

For a transmission medium, e.g. copper wire, this is the range of signal frequencies that it may transmit.

Question 8

Asynchronous serial data transmission

Answer 8

The arrival of data cannot be predicted by the receiver, so a start bit is used to signal the arrival of data and to synchronise the transmitter and receiver temporarily.

Question 9

Communication protocol

Answer 9

A set of pre-agreed signals, codes and rules to be used for data and information exchange between computers, or a computer and a peripheral device such as a printer, that ensure the communication is successful.

Question 10

Handshaking protocol

Answer 10

The sending and receiving devices exchange signals to establish that the receiving device is connected and ready to receive. Then the sending device oordinates the sending of the data, informing that receiver that it is sending. Finally the receiver indicates that it has received the data and is ready to receive again.

Question 11

Baseband system

Answer 11

A system that uses a single data channel in which the whole bandwidth of the transmission medium is dedicated to one channel at a time.

Question 12

Broadband system

Answer 12

A multiple data channel system in which the bandwidth of the transmission medium carries several data streams at the same time.