2. Data transmission
A section of Computer Science, 0478
Listing 10 of 82 questions
Six statements are given about methods of data transmission. Tick (✓) to show if each statement applies to serial simplex, parallel simplex, parallel half-duplex or serial duplex data transmission. Some statements may apply to more than one data transmission method. Statement Serial simplex (✓) Parallel simplex (✓) Parallel half-duplex (✓) Serial duplex (✓) bits are transmitted along a single wire data is transmitted in both directions it is only suitable for distances less than 5 metres bits from the same byte are transmitted one after the other data may not arrive in the correct sequence data is transmitted in both directions, but only one direction at a time A Universal Serial Bus (USB) connection can be used to transmit data from a mobile device to a computer. Give three benefits of using a USB connection for this purpose. Benefit 1 Benefit 2 Benefit 3
0478_w21_qp_12
THEORY
2021
Paper 1, Variant 2
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Complete the statements about data packets and packet switching. Use the terms from the list. Some of the terms in the list will not be used. You should only use a term once. destination address first footer header last main data packets payload routers servers trailer Data is broken down into packets. A data packet has a packet that contains the packet number and the . Each packet could take a different path from the sender to the receiver; this is controlled by . Packets may arrive out of order. Once the packet has arrived, the packets are reordered.
0478_w23_qp_11
THEORY
2023
Paper 1, Variant 1
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The table contains descriptions about data transmission methods. Complete the table by identifying which data transmission methods are described. Data transmission method Description Data is transmitted down a single wire, one bit at a time, in one direction only. Data is transmitted down multiple wires, multiple bits at a time, in both directions, but only one direction at a time. Data is transmitted down a single wire, one bit at a time, in both directions at the same time. Data is transmitted down multiple wires, multiple bits at a time, in one direction only.
0478_w23_qp_12
THEORY
2023
Paper 1, Variant 2
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A company decides to create a network for its devices. All the company devices are within a single room. The employees will need to use their devices to send data to each other and share files. The company decides to send data across the network using packet switching. An employee sends an email to another employee. The email is broken down into packets. Describe the structure of a packet of data for the email. The company decides to use parallel full-duplex data transmission to send the data across the network. Explain the reasons why the company have chosen this method of data transmission. Give two drawbacks of the company using this method of data transmission. Give one other method of data transmission the company could have chosen.
0478_w24_qp_11
THEORY
2024
Paper 1, Variant 1
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An employee has a report that they need to email to their employer. The employee compresses the report file before emailing it. State the effect the compression has on the report file. Give two benefits of compressing the report file before emailing it. The employee decides to use lossless compression to compress the file. Explain why lossy compression is not suitable. When the employee enters the email address, the computer uses Unicode to convert the email address to binary. State what Unicode is an example of. Give two advantages of the computer using Unicode instead of American standard code for information interchange (ASC. Give one disadvantage of the computer using Unicode instead of ASCII. The report is broken down into packets to be emailed. Circle three items of data that can be found in the packet header. trailer originator’s address payload interrupt input operating system destination address antivirus packet number Each packet is sent along a different path from the employee’s device to the employer’s device. Tick (✓) one box to show the name of this method of sending packets. A packet networking B packet circuiting C packet switching D packet transferring A hardware device is used to control the path that each packet takes. Give the name of this hardware device. The email data is checked for errors after it has been transmitted, using an echo check and a checksum. Explain how the echo check is used to check for errors in the email data. In the checksum error detection method, two values are compared after transmission. If the values do not match, an error is detected. Explain why the values not matching would show an error has occurred. The email data is encrypted using asymmetric encryption before it is sent. Give one reason why the email data is encrypted. Give one similarity between symmetric encryption and asymmetric encryption. Give two differences between symmetric encryption and asymmetric encryption.
0478_w24_qp_13
THEORY
2024
Paper 1, Variant 3
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Questions Discovered
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