Correct Answer - Option 2 : 64 kbps
Concept:
Line speed is defined as the number of bits per second that can be transmitted along a digital network.
It is also known as the bit Rate, which is given by:
Line speed (Rb) = mnfs
Where:
n = No. of bits used
fs = sampling freq.
m: No. of signals (messages) multiplexed.
Calculation:
Given: fs = 8 kHz, n = 8 bits
The number of signals multiplexed is not given, so the given TDM is normal PCM only, where only one signal is transmitted.
∴ m = 1
Rb = 8 × 8 kHz
Line speed (Rb) = 64 kbps