Multirate multicast switching networks

Abstract

This paper investigates multirate multicast Clos switching networks which are nonblocking in a wide sense, where a compatible multicast request is guaranteed to be routed without disturbing the existing networks if all requests have conformed to a given routing scheme. The routing strategy discovers (2.875n−1) min(k+r 1/k)+1 middle switches are sufficient for any multirate multicast requests, whereas strictly nonblocking multirate switching networks requires infinite number of middle switches if the range of weights is widely distributed. This paper also shows that Yang and Masson's nonblocking multicast Clos network for pure circuit switching is rearrangeable for multirate multicast communication if each weight is chosen from a given finite set of integer multiplicity. Note that a general rearrangeability of multirate Clos network even for point-to-point communications has not been known yet. In our work, the number of middle switches only depends on the configuration of the switch itself but not on the patterns of connection requests, which is advisable to construct large-scale switching networks.