Data is transmitted using the stop-and-wait ARQ protocol over a 10 km channel with a nominal bit rate of 100 Mbps, a propagation speed of 2 × 108 m/s and processing time is 2 µs. HDLC frames with an information payload of 500 bytes and 2 bytes for FCS are used (assume one 1-byte flag field at each end). ACK frames are the same as info frames but payload is zero bytes.

(a) Calculate the link efficiency.

(b) Calculate the effective bit rate of the link, assuming no transmission errors

2. Repeat last problem when the go-back-N protocol is used with a window size of 2 frames.

3. In Problem 2, what is the minimum window size required for a link efficiency of 100 %?