Unit 3.3 Data Transmission Notes

1. What is personal data?

Personal data: Information that can identify a person, like their name, address, phone number, email, or ID number.

2. What is encryption?

Encryption: It is the process of changing readable information into secret code so that only people with the right key can read it.

3. What is decryption?

Decryption: It is the process of changing secret code back into readable information using the correct key.

4. How is data transmitted over a computer network?

Data is divided into small units called packets.
Packets of data are transmitted from one device to another.
Each packet could take a different route across the network from the sending device to the receiving device.

5. What is an error in data?

Data can sometimes get errors in it if it becomes corrupted when it is being created, accessed, processed, transmitted (sent) or stored.

6. How do errors in data happen?

There are many reasons that errors in data can happen during transmission. Some of the main ones are:

Electricity surges
Interference in radio waves
Crosstalk

7. What is electricity surge?

A surge is when the voltage of the electricity supply suddenly increases. This can cause an error to occur in the data.

8. What is Radio-wave interference?

Sometimes radio waves from one device can disrupt radio waves from another and cause errors in the data. This is called interference.

9. What is attenuation?

When solid objects like walls cause weaken the wireless signals, this phenomena is called attenuation.

10. What is crosstalk?

Sometimes, the electrical energy in one cable can interfere with the electrical energy in another cable and create unwanted effects. This is called crosstalk.

11. What is identity theft?

If hackers manage to get hold of your personal information, they could steal it to use for themselves, this is called identity theft.