A novel architecture for optical TDM switching is introduced, comprising 2 × 2 optical switches integrated onto large substrates, and fibre delay lines. The performance of the architecture is characterised in terms of switch count, crosstalk, frame delay, attenuation and control complexity. It is shown that in the near future a system with 16 inputs and outputs, handling a total of 4096 TDM channels, could be demonstrated experimentally with 448 switches on six substrates using state-of-the-art technology.