Multirate multicast switching networks

This paper investigates multirate multicast Clos switching network which is nonblocking in a wide sense, where a compatible multicast request is guaranteed to be routed without disturbing the existing network if all requests have conformed to a given routing scheme. The routing strategy discovers (2.875n − 1) min (k + r1/k) + 1 middle switches sufficient for any multirate multicast requests, whereas strictly nonblocking multirate switching networks requires infinite number of middle switches if the range of weights can be widely distributed.