CHAROTAR INSTITUTE OF TECHNOLOGY, CHANGA
Assignment5: Error Detection and Correction
Last Date: 21/3/07
Que: 1 Short Question:
- What are the difference between packet errors and bit errors?
- What are even and odd parity?
- What is the difference in between a single bit error and a burst error?
- What are the different types of redundancy checks used in data communication?
- What kind of error VRC can detect?
- What is LRC?
- Is CRC superior to LRC? Why?
- What is an error syndrome?
- Which error detection method uses one’s complement arithmetic?
- Which error detection method consists of just one redundant bit per data?
- Which error detection method involves polynomials?
- Let a protection switch on a D53 (45 Mbps) takes 10ms to complete. What is the worst case error burst length?
- In cyclic redundancy checking, the CRC is ______. [the divisor, the quotient, the dividend, the remainder]
- Hamming code is a method of _____. [error detection, error correction, both]
- CRC can detect all burst of up to m errors, if generator polynomial G(x) is of ___ degree. [m, m-1, m+1, one]
- Find the binary equivalent of
x8 + x3 + x +1
- If a divisor is 101101, how many bits long is the CRC.
- Find the polynomial equivalent of 100001110001.
- Find the complement of 1110010001110011
- Error detection is usually done in the ____ layer of the OSI model. [Physical, Data link, Network].
Que: 2 Give answer:
- Calculate the VRC and LRC for the following bit pattern using even parity.
0011101 1100111 1111111 0000000 [May 2004]
- Given a 10-bit sequence 1010011110 and a divisor of 1011, find the CRC. Check your answer.
- Discuss VRC and LRC mechanism for error detection. [May 2005]
- Generate CRC code for the data 11001 with divisor 1001. Also perform CRC checking procedure. [ May 2005]
- Construct the Hamming Code for the bit sequence 10011101
- The code 11110101101 was received. Using the Hamming encoding algorithm, what is the original code sent?
- A receiver receives the code 11001100111. When it uses the Hamming encoding algorithm, the result is 0101. Which bit is in error? What is the correct code?
- What kind of error is undetected by checksum?
- What is the formula to calculate the number of redundancy bits required to correct a bit error in a given number of data bits?
- What are the conditions for the polynomial used by CRC generator?