Let A and B be two stations attempting to transmit on an Ethernet. Each has a steady queue of frames ready to send; A’s frames will be numbered 1, 2 and so on, and B’s similarly. Let T = 51.2 c be the exponential backoff base unit. Suppose A and B simultaneously attempt to send frame 1, collide, and happen to choose backoff times of 0 × T and 1 × T, respectively. As a result, Station A transmits 1 while Station B waits. At the end of this transmission, B will attempt to retransmit 1 while A will attempt to transmit 2. These first attempts will collide, but now A backs off for either 0 × T or 1 × T (with equal probability), while B backs off for time equal to one of 0 × T, 1 × T, 2 × T and 3× T (with equal probability).(a) Give the probability that A wins this second backoff race immediately after his first collision.(b) Suppose A wins this second backoff race. A transmits 2 and when it is finished, A and B collide again as A tries to transmit 3 and B tries once more to transmit 1. Give the probability that Awins this third backoff race immediately after the first collision.(c) What is the probability that A wins all the backoff races. ( is a given constant)(d) Assume that there are 3 stations sharing the Ethernet. Will the chance for A to win all the backoffraces decrease or increase? Why?

Following are the solution to the given question:

Explanation:

Please find the complete and correct question in the attachment file.  

For Point a:

For the second round,

A is selects kA(2)  either 0 or 1, so for each of them, that is .

B selects for each choice with the probability of .

If  wins the second rear race.

For Point b:

Throughout this example, also selects to be either 0 or 1 with such a probability. So, although B chooses from the probabilities each are :

For point c:

Assume that B tries again 16 times (typical value), and it destroys. In addition, throughout the exponential background n is obtained at 10 when choosing k between 0 to 2n−1. The probability of A winning all 13 backoff events is:

Let the k value kA(i) be A for the backoff race I select. Because A retains the breed

For point d:

Two stations A and B are supposed. They assume that B will try 16 times afterward. Even so, for A, 16 races were likely to also be won at a rate of 0.82 For Just higher expectations of three A, B, and C stations. For Station A, possibility to win all backoffs

given the options, i would say your best bet is c. the modem supports up to 56 kbps, which is too low for video streaming. dial up modems use actual phone lines, which only can go up to 56 kbps as that's more than sufficient for traditional phone calls. this is also the reason why when a dial-up modem connects, you hear all those sounds. it's literally using the phone line to establish a connection.

i think the answer would be a