QUESTION 4 Q 4(a) Describe the categorisation of traffic classes proposed by Recommendation G.1010. ITOTAL MARKS: 25] [7 Marks] Q 4(b) 9 Marks] Consider the use of Weighted Moving average to estimate delay for a VolP application Let -t1 (reception time - timestamp) be the most recent sample delay, let r2-t2 be i) Given i packets received, describe how delay may be estimated using a ii) the next most recent sample delay, and so on Weighted Moving Average. (3 marks) For the first four packets write out the delay estimate in terms of the timestamps and reception times. (3 marks) ) Based on ii) give a general formula for the delay estimate in terms of timestamps and reception times. (3 marks) a 4(c) 9 Marks] Describe three forward error correcting schemes that can be used to preserve audio quality in internet telephony. Comment on overhead and loss recovery for each of these schemes. [End of Question 4] QUESTION 4 Q 4(a) Describe the categorisation of traffic classes proposed by Recommendation G.1010. ITOTAL MARKS: 25] [7 Marks] Q 4(b) 9 Marks] Consider the use of Weighted Moving average to estimate delay for a VolP application Let -t1 (reception time - timestamp) be the most recent sample delay, let r2-t2 be i) Given i packets received, describe how delay may be estimated using a ii) the next most recent sample delay, and so on Weighted Moving Average. (3 marks) For the first four packets write out the delay estimate in terms of the timestamps and reception times. (3 marks) ) Based on ii) give a general formula for the delay estimate in terms of timestamps and reception times. (3 marks) a 4(c) 9 Marks] Describe three forward error correcting schemes that can be used to preserve audio quality in internet telephony. Comment on overhead and loss recovery for each of these schemes. [End of Question 4]