21 minutes ago
Consider the Stop-and-Wait ARQ for the data-link layer on a half-duplex link of 10 kbps.
Specifically, the link connects a sender and a receiver; both can transmit at 10 kbps. The frame
size is set 1 kBytes at the sender, and the acknowledgment size is set to 10 Bytes at the receiver.
The one-way propagation delay is 0.1 second.
(a) Compute the throughput of this link, assuming processing delays at the nodes are negligible
and that the link is 100% reliable (i.e., both the data frame and ACK have zero loss
probability). Express your answer in terms of bps.
(b) Compute the throughput of this link, assuming processing delays at the nodes are negligible
and the transmission of the data frame is not reliable and can be lost with probability 0.2,
but the transmission of the ACK is 100% reliable. Assume the time-out is set to the
minimum that is required. Express your answer in terms of bps.
(c) Returning to part (a) where the link is 100% reliable. Suppose that the link is full-duplex
now (i.e., the data frame transmission and the ACK transmission can occur at the same
time). You want to improve the throughput by using the Go-Back-N ARQ. What is the
minimum N to achieve the maximum throughput? Derive the maximum throughput.