A new design for wide-sense nonblocking multicast switching networks

We propose a design for a wide-sense nonblocking multicast switching network, which has many comparable properties to a strictly nonblocking Clos permutation network. For a newly designed four-stage N × N multicast network, its hardware cost in terms of number of crosspoints is about 2(3 + 2√2)N³2/ = 11.66N³2/, which is only a small constant factor higher than that of a three-stage nonblocking permutation network, and is lower than the O(-N3/2log N/loglog N) hardware cost of the well-known three-stage wide-sense nonblocking multicast network. In addition, the proposed four-stage nonblocking multicast network has a very simple routing algorithm with sub-linear time complexity, and does not require multicast capability for the switch modules in the input stage.