8- Consider the digital TSSST switch shown in the figure in which N = 128 incoming digital signals with 24 channels per frame (time slots). Time expansion (a) is 2 and space expansion ẞ is 1.5. Calculate the complexity of this switch assuming output associated control in all stages. TSSST Switches When the space stage of a TST switch is large enough to justify additional control complexity, multiple space stages can be used to reduce the total crosspoint count. Figure 5.25 depicts a TST architecture with a three-stage space switch. Because the three middle stages are all space stages, this structure is sometimes referred to as a TSSST switch. The EWSD switch of Siemens [9] uses a TSSST structure. The implementation complexity of a TSSST switch can be determined as* NBX + NBT + NBTC Complexity = Nx + 100 where Nx = number of crosspoints, = 2Nk + k (N/n)² NBX = number of space stage control store bits, = 2k(N/n)l log2(n) +k(N/n)! log2(N/n) NBT = number of bits in time stages, = 2Nc (8) NBTC = number of time stage control store bits, = 2Nl log2(c) (5.18)