Assignment #2
ECE 487 (Data Communications Networks)
1. In the following figure, four PCs (with indices 1, 2, 3, and 4) are connected through two bustopology local area networks (LANs). The address configuration is also shown in the figure,
where a capital-case letter means an IP address and a number means a physical address. Any data
frame in the network has the following format:
Assume a process with port address ‘a’ on PC 2 sends a message to a process with port address
‘b’ on PC 3. In the following table, please indicate the source & destination addresses used in the
header of Layers 2, 3, and 4, for the data frame from PC 2 to the router and the data frame from
the router to PC 3. (6 points)
Data frame from PC 2 to the router Data frame from the router to PC 3
Source address Destination address Source address Destination address
Layer 2 header
Layer 3 header
Layer 4 header
2. What is the minimum Hamming distance for the following cases: i) detection of up to six bit
errors; ii) correction of up to six bit errors? (2 points)
3. How many bit errors can be detected and how many bit errors can be corrected if the
minimum Hamming distance is i) 10; ii) 11? (4 points)
4. Using the code In Table 10.2 on Slide 21 of Lecture 3, indicate the decoded dataword if one of
the following codewords is received: a) 10101; b) 11010; c) 00011; d) 11011. Please show your
steps. (8 points)
