I think this helps u.
We can represent Low voltage in two ways and high voltage in two ways as above .
So we draw two waveform for any data...
0 is represented by
1 is represented by
So I draw two encoding scheme.
See, there are 2 standards .
Forouzan along with William stallings book follow IEEE standards . Where Tanenbaum book follows G. E. Thomas standard .
It is just the convention which determine the correct answer.
see this from IIT KGP, they follow IEEE standard - http://nptel.ac.in/courses/Webcourse-contents/IIT%20Kharagpur/Computer%20networks/pdf/M2L4.pdf
and this one from IITB , they follow G E Thomas version --
and we generally follow IEEE standards.
see this gate question https://gateoverflow.in/3505/gate2007-it-61
In IEEE standard '1' is represented by low-to-high and '0' represented by high-to-low .
And according to G.E. Thomas' convention '1' by high-to-low transition and '0' is expressed by a low-to-high transition .
Read that gate question link , read 2 answers and all comments, i assure your all doubts related to differential Manchester will get cleared.
and there is no term as Integral Manchester, It was just put there in question to confuse students.
There is no such topic and term like Integral Manchester encoding . They put this into Gate question to confuse students.
For understanding differential manchester encoding see this thread and clealrly understand 2 given diagrams :