Unit 2: Data Transmission

2.1 Types and methods of data transmission

1 (a) Understand that data is broken down into packets to be transmitted
(b) Describe the structure of a packet
(c) Describe the process of packet switching

2 (a) Describe how data is transmitted from one device to another using different methods of data transmission
(b) Explain the suitability of each method of data transmission, for a given scenario

3 Understand the universal serial bus (USB) interface and explain how it is used to transmit data

2.2 Methods of error detection

1 Understand the need to check for errors after data transmission and how these errors can occur

2 Describe the processes involved in each of the following error detection methods for detecting errors in data after transmission: parity check (odd and even), checksum and echo check

3 Describe how a check digit is used to detect errors in data entry and identify examples of when a check digit is used, including international standard book numbers (ISBN) and bar codes

4 Describe how an automatic repeat query (ARQ) can be used to establish that data is received without error

2.3 Encryption

1 Understand the need for and purpose of encryption when transmitting data

2 Understand how data is encrypted using symmetric and asymmetric encryption