Networks: types, wired/wireless & protocols – GCSE Computer Science exam questions with mark scheme

1Grade 1–33 marks

(a) Describe one difference between a LAN and a WAN. [2]

(b) Give one example of a personal area network (PAN). [1]

(a) LAN side: a LAN covers a small / local geographical area, e.g. one building or one site; or a LAN is usually owned and managed by a single person / organisation(1)
(a) Matching WAN side: a WAN covers a wide / large geographical area, e.g. between cities or countries (allow the Internet as the example); or a WAN is usually under collective / distributed ownership, e.g. uses infrastructure owned by telecoms companies. For 2 marks both sides must be about the same feature (area with area, ownership with ownership); a correct description of only one side (LAN only or WAN only) = 1 mark. A single comparative statement with no detail (e.g. 'a LAN covers a smaller area than a WAN') = 1 mark only(1)
(b) Any example of personal devices connected wirelessly over a short range by Bluetooth, e.g. a mobile phone connected to wireless earbuds / a smartwatch / a car hands-free system; the student does not need to name Bluetooth. 'Bluetooth' alone with no devices = 0 (it names the technology, not an example of a network); allow 'two of my devices connected by Bluetooth'. Reject examples using Wi-Fi or cables (e.g. a home Wi-Fi network is a LAN)(1)
Answer: (a) A LAN covers a small area such as one building; a WAN covers a large geographical area (e.g. across countries). (b) e.g. a phone connected to wireless earbuds by Bluetooth.
Examiner tip: A difference needs both sides: say what the LAN covers AND what the WAN covers.

2Grade 4–54 marks

The diagram shows the network in a small office. All of the devices are in one building and are connected to the switch using copper cables.

(a) State whether the network inside the office is a LAN or a WAN. [1]

(b) The router is going to be connected to the company's head office, 80 km away, using a fibre-optic cable. Give two reasons why fibre-optic cable is more suitable than copper cable for this link. [2]

(a) LAN; allow local area network(1)
(b) Any two from: signals can travel much further / long distances without losing quality (less attenuation, fewer or no repeaters needed); higher bandwidth / can carry more data / faster data transfer; not affected by electromagnetic interference (uses light not electricity); harder to tap / intercept so more secure(1)
(b) Second reason from the list; do not award two marks for 'faster' and 'higher bandwidth' given as the same idea(1)
(c) Any one from: copper is cheaper (to buy / install); easier to install / bend / terminate; distances inside one building are short so copper's speed and range are good enough; network cards / switches already have copper ports(1)
Answer: (a) LAN (b) e.g. fibre carries signals over long distances without degrading; higher bandwidth; not affected by electrical interference (c) copper is cheaper and easier to install, and is good enough over short distances.
Examiner tip: 'Fibre is better' earns nothing – say what is better about it: it carries data further, faster and without interference.

3Grade 4–54 marks

A school is deciding whether to use wired or wireless connections in a new classroom.

(a) Give two advantages of using wireless connections. [2]

(b) Give two advantages of using wired connections. [2]

(a) Any two from: users / devices can move around and stay connected anywhere within range (mobility); no cables needed so cheaper / quicker / easier to install; easier to add new devices (e.g. students' laptops / tablets); no trailing cables / trip hazards; devices without network ports (e.g. tablets) can connect(1)
(a) Second advantage (a different idea from the first)(1)
(b) Any two from: faster data transfer / higher bandwidth; more reliable / stable connection; less affected by interference or by walls and distance; more secure because a physical connection to the network is needed / signals cannot be picked up from outside the room(1)
(b) Second advantage (a different idea from the first); do not award 'faster' and 'higher bandwidth' as two separate points(1)
Answer: (a) Wireless: devices can be used anywhere in range; no cables so easier and cheaper to install. (b) Wired: faster / higher bandwidth; more reliable and less interference; more secure as a physical connection is needed.
Examiner tip: Do not give the same idea twice ('faster' and 'quicker') – the second mark needs a different point.

4Grade 6–76 marks

(a) State the protocol that is used for each purpose. [4]

(i) Sending an email from an email program to a mail server
(ii) Accessing emails stored on a mail server so that they stay synchronised across all of a user's devices
(iii) Making sure that all the packets of a message arrive and are put back together in the correct order
(iv) Securely sending card details to an online shop's website

(b) State the layer of the TCP/IP model at which IP operates. [1]

(a)(i) SMTP; allow Simple Mail Transfer Protocol(1)
(a)(ii) IMAP; allow Internet Message Access Protocol; reject POP / POP3(1)
(a)(iii) TCP; allow Transmission Control Protocol; allow TCP/IP(1)
(a)(iv) HTTPS; allow Hypertext Transfer Protocol Secure; reject HTTP(1)
(b) Internet (layer); do not accept network layer (the alternative layer names are not used in the 2025 specification)(1)
(c) Application (layer)(1)
Answer: (a) (i) SMTP (ii) IMAP (iii) TCP (iv) HTTPS (b) internet layer (c) application layer
Examiner tip: SMTP SENDS mail and IMAP ACCESSES mail stored on the server – swapping them costs both marks; and use AQA's layer names: application, transport, internet, link.

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