Describe TCP/IP layering protocols by considering the following problem: Suppose that the TCP entity receives a 2,000,000 bytes file from the application layer. The TCP entity needs to fragment the file according to the payload size of MAC layer. For each fragment, TCP adds 20 bytes header and passes it to IP. IP in turn adds 20 bytes header and passes it to MAC layer of LAN. Each LAN frame allows a maximum payload (data part) of 1500 bytes and a header of 18 bytes. (Note that packet fragmentation can occur at any layer. In this exercise, it occurs at TCP layer, not the MAC layer. Each fragment carries TCP header, IP header and MAC header.) (i) Sketch a diagram to show the protocol layering and fragmentation process. (4 marks) (ii) How many fragments are generated by the TCP entity? What is the size of each fragment? (4 marks) (iii) How many bytes including headers, are delivered to the destination host? (3 marks) (iv) What is the total percentage overhead of headers? (i.e. total header bytes/total bytes delivered) (3 marks) (b) The thermal noise power of a channel with a bandwidth of 400 kHz is 1.776 x 1015 watts, what is its operating temperature in ? (3 marks) (c) Consider a communication channel with 500 kHz bandwidth. (i) If one wishes to transmit at a data rate of 8.3 Mbps, what is the minimum signal-to- noise ratio in dB required to accomplish this? (5 marks) (ii) If the effective data rate is 80% of the maximum channel data rate. What is ratio of signal energy per bit to noise power density (i.e. Eb/N0)?