# Computer Science - Networking - Discussion

### Discussion :: Networking - Section 1 (Q.No.3)

3.

The probability that a single bit will be in error on a typical public telephone line using 4800 bps modem is 10 to the power -3. If no error detection mechanism is used, the residual error rate for a communication line using 9-bit frames is approximately equal to

 [A]. 0.003 [B]. 0.009 [C]. 0.991 [D]. 0.999 [E]. None of the above

Explanation:

No answer description available for this question.

 M.Venkat said: (Nov 3, 2011) 1-1/1000

 Suresh Kumar said: (Dec 9, 2011) What is the method/theory to solve this question?

 Dipayan Das said: (Mar 3, 2012) 1bit error probability 1/1000 9bit error probability 9/1000 .ie .009

 Aniruddha said: (Aug 13, 2012) Here the data rate of 4800 bps is redundant information. Probability that a single bit is in error 10^-3 = 0.001t Probability that a single bit is not in error = 1 - 0.001 = 0.999 In a frame of 9 bits the residual error rate value signifies the probability that at least one of the bits out of the nine is in error. Thus, chances that all 9 bits are correct = 0.999^9 = 0.991 (approx) Residual error rate = chances that at least one of 9 bits is incorrect = 1 - 0.991 = 0.009 (approx)

 Sagar said: (Oct 30, 2012) Thus, chances that all 9 bits are correct = 0.999*9 = 0.991 (approx) Residual error rate = chances that at least one of 9 bits is incorrect = 1 - 0.991 = 0.009 (approx)

 P.Tarun said: (Dec 20, 2012) Here the data rate of 4800 bps is redundant information. Probability that a single bit is in error 10^-3 = 0.001t Probability that a single bit is not in error = 1 - 0.001 = 0.999 In a frame of 9 bits the residual error rate value signifies the probability that at least one of the bits out of the nine is in error. Thus, chances that all 9 bits are correct = 0.999^9 = 0.991 (approx) Residual error rate = chances that at least one of 9 bits is incorrect = 1 - 0.991 = 0.009 (approx)

 Geetu said: (Aug 9, 2015) Please tell me how can I easily solve?

 Shivakumar_Bpt said: (Sep 8, 2016) Probability that a single bit is in error 10^-3 = 0.001t. Probability that a single bit is not in error = 1 - 0.001 = 0.999.