Communication Systems - Engineering

Q1:

A three stage telephone switching structure is to have 128 input and 128 output terminals. There are 16 first stage and 16 third stage matrices. To avoid blocking the number of intermediate paths required is

A 16

B 15

C 8

D 1

ANS:B - 15

Total paths required is 16 no of intermediate paths are 15 i.e; except considered path all are intermediate.

To avoid blocking all input's should have output path.