(a(i))[2]
Explain the meaning of regeneration.
(a(ii))[2]
Explain why regeneration cannot be applied to an analogue signal.
(b(i))[2]
Digital signals travel through an optic fibre by means of infra-red radiation. The continuous length of the optic fibre is $58\ \text{km}$. The effective noise level in the receiver at the far end of the optic fibre is $0.38\ \mu\text{W}$. The least acceptable signal-to-noise ratio in the receiver is $32\ \text{dB}$. Calculate the minimum acceptable power $P_{\text{MIN}}$ of the signal at the receiver.
(b(ii))[2]
The power entering the optic fibre is $9.5\ \text{mW}$. The output power equals $P_{\text{MIN}}$. Calculate the attenuation per unit length of the optic fibre.