(a) Describe the operation of the Go-Back-N Automatic Repeat Request (ARQ) strategy. (b) In the case where bit errors are independent, derive expressions for the average time to transmit a data frame and the transmission efficiency when using Go-Back- N ARQ A data link has a path delay of 3 msec and a transmission rate of 1 MBytes/sec. The data frame has 256 bytes of information, a 2 byte start field, a 32 byte header and an 8 byte check field. The acknowledgement information is 'piggy-backed' or returning data frames. The processing time is 5 sec. If the bit error ratio is 5 x 10-5 determine the average data rate that is achieved, the size of the buffer needed to correct for a single frame error, and the probability that the buffer size will not be sufficient in general operation. (c)