CRC
Question 1 
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 
Question 1 Explanation:
Given CRC generator polynomial =x^{3}+x+1
=1∙x^{3}+0∙x^{2}+1∙x^{1}+1∙x^{0}
=1011
Message =01011011
So, the message 01011011 is transmitted as
=1∙x^{3}+0∙x^{2}+1∙x^{1}+1∙x^{0}
=1011
Message =01011011
So, the message 01011011 is transmitted as
Question 2 
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

Question 2 Explanation:
CRC polynomial = x^{3}+1 [∵ In data 3zero’s need to be append to data]
= 1001
∴ Data transmitted is: 11001001011
= 1001
∴ Data transmitted is: 11001001011
There are 2 questions to complete.