17.2 Problem Compression reliability tradeoff * In this question, we will examine the tradeoff between compression and error resilience through a back - of- the - envelope calculation. Suppose we have 15 frames to transmit and two possible GoP structures: (A) IPB and (B) IPBBB. Suppose an I frame costs 7 kB, a P frame costs 3 kB, and a B frame costs 1 If an entire GoP is not received correctly, we assume that the GoP must be sent again. As our metric of error resilience, consider the expected number of bits that must be retransmitted at least once. The probability of dropping a frame is 1% and assumed to be independent. (These assumptions are made to simplify this homework problem. In a P or B frame in a GoP is lost, the entire GoP does not need to be retransmitted. Loss is not independent and usually much less than 1%. And there should be many more frames.) (a) In case A, the video frame structure is IPB/IPB/IPB/ IPB/IPB. What is the total cost of the video in KB? What is the cost per GoP? (b] What is the probability than an entire GoPis transmitted successfully in case A? What is the expected number of GoPs that ere successful on the first transmission atte pt of the entire video? What is the expected number of GoPs that must be retransmitted at least once? How much does the first retransmission cost in kB? 17.2 Problem Compression reliability tradeoff * In this question, we will examine the tradeoff between compression and error resilience through a back - of- the - envelope calculation. Suppose we have 15 frames to transmit and two possible GoP structures: (A) IPB and (B) IPBBB. Suppose an I frame costs 7 kB, a P frame costs 3 kB, and a B frame costs 1 If an entire GoP is not received correctly, we assume that the GoP must be sent again. As our metric of error resilience, consider the expected number of bits that must be retransmitted at least once. The probability of dropping a frame is 1% and assumed to be independent. (These assumptions are made to simplify this homework problem. In a P or B frame in a GoP is lost, the entire GoP does not need to be retransmitted. Loss is not independent and usually much less than 1%. And there should be many more frames.) (a) In case A, the video frame structure is IPB/IPB/IPB/ IPB/IPB. What is the total cost of the video in KB? What is the cost per GoP? (b] What is the probability than an entire GoPis transmitted successfully in case A? What is the expected number of GoPs that ere successful on the first transmission atte pt of the entire video? What is the expected number of GoPs that must be retransmitted at least once? How much does the first retransmission cost in kB