Space division switch
Example: Build an NxN crossbar by staging.
Use three stages.
- First stage has (N/n) crossbars. Each crossbar has n x k crosspoints, n input and k output.
- Second stage has k crossbars with (N/n)x(N/n) crosspoints.
- Third stage is like first but with input and output reversed.
Number of crosspoints = 2kN + k(N/n)^2