Which one is best either B8ZS or HDB3 and why?

Which one is best either B8ZS or HDB3 and why?

Solution:-in my view HDB3 is more effective as it extracts a group of consecutive four zeros instead of 8 zeros which is complicated and cumbersome.

And also there is a greater chance of error in case of B8ZS. As small chunks or groups of zeros are more easily managed and extracted. but if we implement B8ZS then we overcome the overhead of extracting zeros repeatedly and at once we extract a large number of zeros.

Salient features of B8ZS:-Convention adopted in North America to provide synch for long string of zeros. Difference b/w AMI and B8ZS occurs only when 8 or more consecutive zeros are encountered. Forces artificial signal changes called VIOLATIONS.

Each time eight 0’s occur , B8ZS introduces changes in pattern based on polarity of previous 1 (the ‘1’ occurring just before zeros)

Salient features of HDB3:-Alteration of AMI adopted in Europe and Japan

Introduces changes into AMI, every time four consecutive zeros are encountered instead of waiting for eight zeros as in the case of B8ZS. As in B8ZS, the pattern of violations is based on the polarity of the previous 1 bit. Unlike B8ZS, HDB3 also looks at the no. of 1’s that have occurred since the last substitution.

Polarity of 1 since last substitution means that the number of 1’ encountered since the last and recent one event when the group of zeros were extracted.