Problem 23
Name a network that allow frames to be packed back-to-buck. Why is this feature worth having?
Problem 25
Give an example to show that the RTS/CTS in the \(802.11\) protocol is a litule different than in the MACA protocal.
Problem 28
Suppose that an 11-Mbps \(802.11 \mathrm{~b}\) LAN is transmitting 64-byte frames back-lo-back over a radio channel with a bit error rate of \(10^{-7}\). How many frames per second will be damaged on average?
Problem 29
Two devices connected to the same \(802.11\) network are both downloading a large file from the Intemet. Explain bow one device could obtain a higher data rate than the other by (ab)using a \(802.11\) mechanism intended to provide quality of service.
Problem 31
Give two reasons why networks might use an crror-correcting code instcad of error detection and netransmission.
Problem 33
A disadvantage of Bluetooth's profiles is that they add significant complexity to the protocol. How can these profiles be an advantage from the perspective of the applicattions?
Problem 39
Beacon frames in the frequency hopping spread spectrum variant of \(802.11\) contain the dwell time. Do you think the analogous beacon frames in Bluetooth also contain the dwell time? Discuss your answer.
Problem 45
Briefly deseribe the difference between store-and-forward and cut-through switches.
Problem 47
Consider two Ethemet networks. In network (a), stations are connected to a hub via full-duplex cables. Ia network (b), stations are connected to a switch using half-duplex eables. For cach of these networks, why is CSMANCD (not) needod?
Problem 48
Store-and-forward switches have an advantage over cut-through switches with respoct to damaged frames. Fxplain what it is.
