AQA Level 3 Technical Level IT: CYBER SECURITY IT: NETWORKING IT: USER SUPPORT Unit 2 Communication technologies Mark Scheme

Level 3 Technical Level IT: CYBER SECURITY IT: NETWORKING IT: USER SUPPORT Unit 2 Communication technologies Tuesday 21 May 2019 Afternoon Time allowed: 2 hours Materials For this paper you must have: • a ruler • a scientific calculator (non-programmable) • stencils or other drawing equipment (eg flowchart stencils). Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer each question in the space provided. Do not write outside the box around each page or on blank pages. • Do all rough work in this book. Cross through any work you do not want to be marked. • If you need more space use the additional pages at the back of this booklet. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 80. • There are 50 marks in Section A and 30 marks in Section B. Both sections should be attempted. Advice • In all calculations, show clearly how you work out your answer. • Use diagrams, where appropriate, to clarify your answers. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. Section A Answer all questions in this section. box 0 1 Gigabit Ethernet increased potential speeds to Tick () one box. [1 mark] 128 Mbit/s 256 Mbit/s 512 Mbit/s 1000 Mbit/s 0 2 Which of the following is a component of a smartphone? Tick () one box. [1 mark] Carbon transmitter Central Processing Unit (CPU) Cooling fan Switch hook *02* 0 3 A personal unlocking key (PUK) is needed when Tick () one box. [1 mark] a mobile phone has been stolen. a PIN code has been entered incorrectly several times. a smartphone is locked by a service provider. using a CDMA phone with no SIM card. 0 4 Tethering is Tick () one box. [1 mark] a public Wi-Fi hotspot for unlimited users. a way of downloading unlimited data. not possible on Android phones. sharing a mobile device’s Internet connection. Turn over for the next question Turn over ► No need for a domain name box Prevents malware infections Resource sharing . State two different media used in wired transmissions. [2 marks] box 1 2 . Explain how electromagnetic interference (EMI) can be reduced when using wired transmission media. [2 marks] . What does DTE stand for? [1 mark] . Give one example of DTE you would find in an Internet-connected home. [1 mark] Turn over for the next question Turn over ► The OSI model and TCP/IP model are layered conceptual models. . Complete Table 1, entering the names of the four missing TCP/IP layers and the names of the four missing OSI layers not shown. box [4 marks] Table 1 Layer OSI model TCP/IP model Layer 7 Application layer 4 6 Presentation layer 5 4 3 3 2 2 Data link layer 1 1 . State the purpose of the third layer of the TCP/IP model. [1 mark] . State one of the protocols operating at the third layer of the TCP/IP model. [1 mark] Explain the purpose of repetition code. [2 marks] box . What is over-the-air (OTA) programming? [2 marks] . Give two examples of what OTA is used for. [2 marks] 1 2 Turn over for the next question *07* Turn over ► Compare local area networks (LANs) with wide area networks (WANs). [4 marks] box *0* . Define bandwidth throttling. [2 marks] box . Explain why an Internet Service Provider (ISP) might use bandwidth throttling. [2 marks] Turn over for the next question Turn over ► box . Give two reasons why a contractor might install unshielded twisted pair (UTP) cable rather than shielded twisted pair (STP) cable. box [2 marks] 1 2 . Whether using UTP cable or STP cable, networks make use of repeaters. Explain the purpose of a repeater. [2 marks] Turn over for the next question Turn over ► . Define the function of the routing information protocol (RIP). [2 marks] box . Explain the operation of the RIP. [3 marks] . Explain why theoretical Ethernet speed ratings are not achievable in real-world situations. box [2 marks] . Only 2% of homes in the UK are able to receive fibre directly from the exchange. This is known as Fibre to the Home (FTTH). These homes benefit from download speeds of up to 1 Gbps. Most UK fibre connections are from the exchange to the cabinet in your street and then connect to a standard phone line into your house. This type of connection is called Fibre to the Cabinet (FTTC). These typically offer advertised speeds of between 38 Mbps and 76 Mbps. Explain the potential causes of the significant reduction in speed of an FTTC connection compared with an FTTH connection. [4 marks] Turn over for Section B Turn over ► Section B Answer all questions in this section. box Describe the features of • LCD displays • LED displays. [6 marks] Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Turn over ► “TCP is reliable and guarantees delivery of data. UDP is unreliable.” Discuss this statement. In your answer you must include: • an explanation of how data is transferred to and from a mobile device in a cellular network • how these two protocols (TCP, UDP) operate that might suggest one is more reliable in guaranteeing delivery of data than the other. box [9 marks] box Turn over for the next question *17* Turn over ► Computer networking devices (networking hardware) are needed for communication between devices on a computer network. Discuss five computer networking devices needed in a computer network. box For each device, your answer must include: • why the device is useful/required • the features of the device • what the device does. [15 marks] *1* box END OF QUESTIONS *19* Turn over ► If needed, use the following pages to continue your answers. Write the question number beside your answer. box *20* IB/M/Jun19/H/507/6426 box There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED box Copyright information For confidentiality purposes, from the November 2015 examination series, acknowledgements of third-party copyright material are published in a separate booklet rather than including them on the examination paper or support materials. This booklet is published after each examination series and is available for free download from after the live examination series. Permission to reproduce all copyright material has been applied for. In some cases, efforts to contact copyright-holders may have been unsuccessful and AQA will be happy to rectify any omissions of acknowledgements. 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