34 votes 34 votes A computer network uses polynomials over $GF(2)$ for error checking with $8$ bits as information bits and uses $x^{3}+x+1$ as the generator polynomial to generate the check bits. In this network, the message $01011011$ is transmitted as: $01011011010$ $01011011011$ $01011011101$ $01011011100$ Computer Networks gatecse-2017-set1 computer-networks crc-polynomial normal + – Arjun asked Feb 14, 2017 • edited Jun 20, 2018 by Milicevic3306 Arjun 11.8k views answer comment Share Follow See all 8 Comments See all 8 8 Comments reply Show 5 previous comments mahendrapatel commented Dec 28, 2022 reply Follow Share Then what is effect of it on question ??? 0 votes 0 votes Abhishek Rauthan commented Jan 12, 2023 reply Follow Share @Pranavpurkar GF(2) basically means a set which comprises of 0 and 1 or a polynomial the coefficient of which is only 0 or 1. src: https://www.sharetechnote.com/html/Handbook_Communication_GF2.html @mahendrapatel the effect on this question is as the generator polynomial is given as x^3+x+1 so each of its coefficient can take only two value 0 or 1. 1 x^3+0.x^2+1.x+1 5 votes 5 votes mahendrapatel commented Jan 13, 2023 reply Follow Share This answer was needed,clear bhai Sukriya dil se❤️ 2 votes 2 votes Please log in or register to add a comment.
Best answer 50 votes 50 votes The generator polynomial has degree $3.$ So, we append $3$ zeroes to the original message. Correct Answer: $C$ Smriti012 answered Feb 15, 2017 • edited Jun 13, 2021 by S k Rawani Smriti012 comment Share Follow See all 4 Comments See all 4 4 Comments reply hmrishavbandy commented Feb 1, 2021 reply Follow Share This division is completely wrong ! How is this the correct ans ?? The remainder is also not 101. It is 10 ! 2 votes 2 votes forever_Learner commented Jan 11, 2022 reply Follow Share U omit the first 4 bits in the division because the decimal equivalent of the divisor i.e 11 is greater than that of dividend i.e 5, am I right here? somewhere above in comments, said that if L.H.S of the message contains any no of 0's then we can neglect it. neglect leading 0's anywhere during calculation. does this logic imply correct here? 1 votes 1 votes hmrishavbandy commented Jan 11, 2022 reply Follow Share Actually lol the thing is that this division is modulo 2 division. I did not know that then. In modulo 2 division instead of subtracting, you do XOR between the numbers to obtain the next number to divide with. 0 votes 0 votes forever_Learner commented Jan 11, 2022 reply Follow Share that thing I know that we are doing XOR operation only, but in this question, the way we approach is similar as that of division approach. 0 votes 0 votes Please log in or register to add a comment.
42 votes 42 votes So,$C)$ is the correct answer. akash.dinkar12 answered Apr 1, 2017 • edited Jan 21, 2019 by Lakshman Bhaiya akash.dinkar12 comment Share Follow See all 0 reply Please log in or register to add a comment.
11 votes 11 votes here generator is 1011 Clearly on dividing the message by it we get 101 to be padded at end and only option C contains that so OPTION (C) is correct sriv_shubham answered Feb 14, 2017 • edited Jan 16, 2018 by Puja Mishra sriv_shubham comment Share Follow See all 3 Comments See all 3 3 Comments reply MohanK commented Dec 25, 2020 reply Follow Share Hi,@sriv_shubham, I tried to take decimal equivalent of both 01011011 & 01011011000 and divided it by 1011. I didn’t get 101 as remainder. can u pls elaborate on your answer ? Thanks in advance 0 votes 0 votes hmrishavbandy commented Feb 1, 2021 reply Follow Share This is a wrong ans. I am also not getting 101 as remainder. The remainder is 10 and ans is A 0 votes 0 votes ꧁༒☬ĿọŗԀ 🆂🅷🅸🆅🅰☬༒꧂ commented Mar 13 reply Follow Share I think you did mistake somewhere 0 votes 0 votes Please log in or register to add a comment.