Question 21 Not yet answered Marked out of 1.00 In the method, after the station finds the line idle, it sends its frame immediately. If the line is not idle, it continuously senses the line until it finds it idle. P Flag question Select one: O a. CSMA O b. p-persistent O c. nonpersistent O d. 1-persistent Question 22 Stop and Wait ARQ uses the following variable(s) Not yet answered Marked out of 1.00 Select one: O a. Sn only O b. Rn at the receiver side, Sn at the sender c. Rn at the sender side, Sn at the receiver side. Flag question O d. Rn and Ack Question 23 Not yet Given the dataword 1010011110 and the divisor 10111, using polynomials CRC, the codeword is answered Marked out of 1.00 Select one: O a. x2 + x3 + x2 + x + 1 P Flag question O b. X+1 O c. x11+x+x+x+x+ + 1 O d. x4+x2 + x + 1 Which of the following primarily uses guided media? Question 24 Not yet answered Marked out of 1.00 P Flag question Select one: O a. radio broadcasting O b. satellite communications O c. local telephone system O d. cellular telephone system Microwaves are Question 25 Not yet answered Marked out of 1.00 P Flag question Select one: O a. omnidirectional O b. line of sight O c. bidirectional O d. unidirectional