On Nonblocking Switching Networks Composed of Digital Symmetrical Matrices

Significant advances in semiconductor technology make it possible to construct new components called digital symmetrical matrices, which mix in the same integrated circuit, time and space switching. In this paper, structures of multistage nonblocking networks composed of such matrices are described. The condition under which the network will be nonblocking is formulated, and the relationship between the maximal capacity of the network and the number of switching stages is discussed. Formulas for designing optimal threeand five-stage networks are derived. It is shown that general multistage networks should have as few stages as possible for minimizing the cost.