Answer the follwoing problems.

problem 1) Compare propagation delay in sending an x-bit message over k-hop circuit switched network and in a lightly loaded packet switched network. Circuit setup time is i seconds, propagation delay is d seconds per hop, packet size is p bits and the data rate is b bps. Under what circumstances does the packet switched network have the lower delay?

problem 2) Measurements of slotted Aloha channel with the infinite number of users demonstrate that 10 percent of the slots are idle. Determine the channel load, G? find out the throughput S? Is the channel underloaded or overloaded?

problem 3) Two CSMA/CD stations are each trying to transmit long (multi-frame) files. After each frame is sent, they contend for the channel using binary exponential backoff algorithm. Determine the probability that contention ends on round k, and what is the mean number of rounds per contention period?

problem 4) Ethernet frames should be at least 64 bytes long to make sure than the transmitter is still going in the event of a collision at the far end of the cable. Fast Ethernet (100 Mb/s) has the same 64 byte minimum frame size, but can get the bits out ten times faster. How is it possible to maintain same frame size?

problem 5) A university computer science department has 3 Ethernet segments, connected by two transparent bridges into the linear network. One day the network administrator quits and is speedily replaced by someone from computer center, which is the IBM token ring shop. The new administrator, noticing that the ends of the network are not connected, quickly orders a new transparent bridge and connects both loose ends to it, making a closed ring. What happens next. Describe your answer.