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Recent questions tagged error-detection

1 vote
1 answer
Following text and screenshot are taken from Forouzan's CN book: "In a linear block code, the exclusive OR (XOR) of any two valid codewords creates another valid codeword." My question is EXoring of which two codewords in Table 10.2 will create first codeword 00000?
asked Jul 31, 2017 in Computer Networks Manu Thakur 784 views
0 votes
1 answer
3 votes
1 answer
Suppose that a message 1001 1100 1010 0011 is transmitted using Internet Checksum (4-bit word). What is the value of the checksum?
asked Sep 14, 2016 in Computer Networks dd 3.3k views
4 votes
2 answers
Data is transmitted continuously at $2.048$ Mbps rate for $10$ hours and received $512$ bits errors. What is the bit error rate? $\text{6.9 e-9}$ $\text{6.9 e-6}$ $\text{69 e-9}$ $\text{4 e-9}$
asked Jun 21, 2016 in Computer Networks Sanjay Sharma 2.7k views
2 votes
2 answers
A block of bits with $n$ rows and $m$ columns uses horizontal and vertical parity bits for error detection. If exactly 4 bits are in error during transmission, derive an expression for the probability that the error will be detected.
asked Jun 1, 2016 in Computer Networks jothee 407 views
3 votes
4 answers
Consider the use of Cyclic Redundancy Code (CRC) with generator polynomial $G(x)$ for error detection. Recall that error detection with a CRC works by appending the CRC value to the bit sequence to make it a multiple of $G(x)$ ... a burst error of length $5$ in such a way that the error cannot be detected by the CRC with the $G(x)$ given above.
asked May 29, 2016 in Computer Networks jothee 922 views
2 votes
5 answers
How many check bits are required for $16$ bit data word to detect $2$ bit errors and single bit correction using hamming code? $5$ $6$ $7$ $8$
asked Apr 26, 2016 in Computer Networks makhdoom ghaya 5.3k views
2 votes
1 answer
How many parity bits will be required for transmitting a 16-bit data ? a 6 b 3 c 2 d 1
asked Apr 19, 2016 in Computer Networks shivanisrivarshini 984 views
21 votes
4 answers
In a communication network, a packet of length $L$ bits takes link $L_1$ with a probability of $p_1$ or link $L_2$ with a probability of $p_2$. Link $L_1$ and $L_2$ have bit error probability of $b_1$ and $b_2$ ... $[1 - (b_1 + b_2)^L]p_1p_2$ $(1 - b_1)^L (1 - b_2)^Lp_1p_2$ $1 - (b_1^Lp_1 + b_2^Lp_2)$
asked Nov 4, 2014 in Computer Networks Ishrat Jahan 3.2k views
3 votes
2 answers
A software was tested using the error seeding strategy in which 20 errors were seeded in the code. When the code was tested using the complete test suite, 16 of the seeded errors were detected. The same test suite also detected 200 non-seeded errors. What is the estimated number of undetected errors in the code after this testing? 4 50 200 250
asked Nov 2, 2014 in IS&Software Engineering Ishrat Jahan 1k views
25 votes
9 answers
An error correcting code has the following code words: $00000000, 00001111, 01010101, 10101010, 11110000$. What is the maximum number of bit errors that can be corrected? $0$ $1$ $2$ $3$
asked Oct 30, 2014 in Computer Networks Ishrat Jahan 7.8k views
24 votes
9 answers
Data transmitted on a link uses the following $2D$ parity scheme for error detection: Each sequence of $28$ bits is arranged in a $4\times 7$ matrix (rows $r_0$ through $r_3$, and columns $d_7$ through $d_1$) and is padded with a column $d_0$ and row $r_4$ of parity bits ... shows data received by a receiver and has $n$ corrupted bits. What is the mini­mum possible value of $n$? $1$ $2$ $3$ $4$
asked Oct 29, 2014 in Computer Networks Ishrat Jahan 5.4k views
15 votes
6 answers
What is the distance of the following code $000000$, $010101$, $000111$, $011001$, $111111$? $2$ $3$ $4$ $1$
asked Oct 8, 2014 in Computer Networks Kathleen 2.1k views
18 votes
5 answers
Following $7$ ... (assuming that at most $1$ bit could be corrupted). If the message contains an error find the bit which is erroneous and gives correct message.
asked Oct 6, 2014 in Computer Networks Kathleen 2.1k views
35 votes
6 answers
Let $G(x)$ be the generator polynomial used for CRC checking. What is the condition that should be satisfied by $G(x)$ to detect odd number of bits in error? $G(x)$ contains more than two terms $G(x)$ does not divide $1+x^k$, for any $k$ not exceeding the frame length $1+x$ is a factor of $G(x)$ $G(x)$ has an odd number of terms.
asked Sep 22, 2014 in Computer Networks Kathleen 11.2k views
20 votes
4 answers
The message $11001001$ is to be transmitted using the CRC polynomial $x^3 +1$ to protect it from errors. The message that should be transmitted is: $11001001000$ $11001001011$ $11001010$ $110010010011$
asked Sep 22, 2014 in Computer Networks Kathleen 9.4k views
16 votes
4 answers
Consider a $3$-$bit$ error detection and $1$-$bit$ error correction hamming code for $4$-$bit$ data. The extra parity bits required would be ___ and the $3$-$bit$ error detection is possible because the code has a minimum distance of ____.
asked Sep 13, 2014 in Computer Networks Kathleen 3.6k views