Question

What is the unit of measurment of transmission signal frequency?

Answer 1

The unit interval is the minimum time interval
between condition changes of a data
transmission signal , also known as the pulse
time or symbol duration time.
A unit interval (UI) is the time taken in a data
stream by each subsequent pulse (or symbol).
Time is a physical quantity. The UI is used as
a unit of measurement of time and represents
a definite predetermined time interval. Saying
10 unit intervals (or 10 UI), actually means 10
times the definite predetermined time called
"UI".
When UI is used as a measurement unit of a
time interval, the resulting measure of such
time interval is dimensionless. It expresses
the time interval in terms of UI.
Very often, but not always, the UI coincides
with the bit time, i.e. with the time interval
taken to transmit one bit (binary information
digit).
The two coincide in fact in NRZ transmission;
they do not coincide in a 2B1Q transmission,
where one pulse takes the time of two bits.
For example, in a serial line with a baud rate
of 2.5 Gbit/s, a unit interval is 1/(2.5 Gbit/s)
= 0.4 ns/baud.

Answer 2

hertz is measurements unit of transmission signal frequency