Design of wide-sense nonblocking multicast ATM switches

Nonblocking multicast asynchronous transfer mode (ATM) switches can simplify the call admission control process and increase the external links' utilization. We derive the wide-sense nonblocking condition for multicast ATM switches based on a general Clos network. We also propose a routing algorithm to achieve wide-sense nonblocking. It is illustrated by an example that the number of required middle stages in our switch is significantly less than that of strictly nonblocking multicast switches.