Q1: 24-bit messages are transmitted using a Hamming code.

a. How many check bits are needed to ensure that the receiver can detect and correct singlebit errors if the dataward was 3 bits?

b. Show the bit pattern transmitted for the message 11001011010010001011101. Assume that even parity is used in the Hamming code.

Q2 : Suppose that a sender and a receiver are using ARQ to perform reliable data delivery. In a Go-Back-N ARQ protocol, the window size is 8. Frames with sequence numbers 1, 2, 3, 4 and 5 have been sent. The sender just received an ACK for frame 1. Frames 6, 7, 8, 9 and 10 are waiting to be sent. Draw the time diagram showing this scenario.

Q3)Dynamic Source Routing is a reactive routing protocol used in wireless networks.

How is reactive routing different from proactive routing?

What are the pros and cons of reactive of routing?

Pros	Cons

Illustrate how DSR constructs a route between a source S and and destination K in the network above. Clearly show the routing information stored in each RREQ packet and the routing information stored in each node. (Use the blank pages at the end)

Assume that in the route constructed in part (c), the last link (i.e. the link connected to K) becomes broken. Show when and how DSR will fix this problem. (Use the blank pages at the end)

MHL