AQA A LEVEL Communication Technologies IT: H/507/6426 Report on the Examination

AQA A LEVEL Communication Technologies IT: H/507/6426 Report on the Examination Q8.1 this proved to be a very well answered question, with most students achieving full marks. The mark scheme allowed some credit for correct completion of the OSI model OR the TCP/IP model, with part credit reserved for students who succeeded in putting together a correct pairing, even if on an incorrect row. Q8.2 most students did gain a mark here. Some students made inappropriate reference to 'headers and footers' (when presumably intending reference to headers used as part of packaging message data) for which a mark was not allowed. Q8.3 again, most students did gain a mark here, most commonly for UDP. IMAP and HTTP were among the many incorrect responses. Q9 It was clear students understood and had covered repetition code, with many references to the use of repetition code as a means of error-detection and error-checking. Q10.1 most students achieved 1 mark here. However some students gained no marks for making reference to 'programming' and then failing to provide any explanation or expansion, some essentially doing no more than repeating / rephrasing the question. Q10.2 again, most students achieved 1 mark here, and there was a pleasing range of examples provided. Q11 most students achieved just 2 marks. Some students lost marks by saying little more than WANs cover a wide area or that LANs cover a local area (each insufficient alone for a mark), The students that did achieve the full 4 marks typically made reference to the relationship between LANs and peripherals, and WANs and multiple LANs, and - popularly - the Internet being the largest WAN. Q12.1 most students achieved 1 mark here, with most making reference to deliberate action by the ISP. Q12.2 again, most students achieved 1 mark here, students making appropriate reference to ISPs prioritising users (justifying both advantaging and disadvantaging heavy users) in an effort to reduce bandwidth congestion and regulate network traffic. Q13.1 This question was very well answered. Q13.2 this was intended to be a very specific and slightly more challenging question and it was pleasing to find most students achieved 2 or 3 marks. References to data roaming and mobile data were common, as was reference to GSM. Q14.1 despite this being intended as a more challenging, more thoughtful question, most students did achieve both marks here. The range of responses included reference to UTP being the faster copper-based medium, and pleasing recognition that STP is simply unnecessary where EMI is minimal. Q14.2 most students achieved 1 mark here, with references to boosting or amplifying or extending a signal common, as well as recognition of the importance of maintaining signal integrity. Q15.1 this more challenging question did result in most students achieving just 1 mark. There were numerous incorrect references to MAC addressing and IP addressing and few references indeed to a routing table. Some students gained a mark for referencing point to point routing of data; other students lost a mark for referencing 'routing of information' and essentially doing no more than repeating / rewording the question. Q15.2 while it was recognised from the outset that this would be a very challenging question it was pleasing to see that a number of students did achieve the full 3 marks, with pleasing summaries that included, for example, "routers sending out discovery requests and routing information directly . . sharing routes learned periodically . . and calculated through distance-based hop counts". Q16.1 most students achieved 1 mark here, with references to resistance and attenuation, congestion and bottlenecks common. Q16.2 here again it was recognised that this would be a very challenging question. Some students did achieve full marks, with reference to, for example, "optical fibre capable of greater (faster) speeds, lower latency, and much less noise, mostly unaffected by traditional issues with EMI". 2 SECTION B: Question by Question analysis Q17 while some students did achieve the full 6 marks for this determinedly challenging question, and while 10% of all students achieved more than half marks, a little more than 10% of all students did not attempt this question. Those students who were successful here knew that LED displays are typically thinner, brighter, offer better resolution, and improved pixels per inch; credit was given for simply knowing LCD involved crystal display while LEDs are light-emitting diodes. Successful students knew that LEDs generated their own light while LCD crystals were either on or off, open or closed, allowing light through or blocking light. Q18 this was perhaps the most challenging question of the paper, demanding in-depth knowledge of the protocols of the TCP/IP model