Controller for a non-blocking broadcast network

Claim 1

A controller for a nonblocking broadcast switching network having N 2 or r 1 input stage switches with N 1 or n 1 r 1 input ports and where each input switch has n 1 input ports and N 1 =n 1 r 1 where r 1 ≧1 and n 1 ≧1 and are integers, r 2 output stage switches with n 2 r 2 output ports where each output switch having n 2 output ports and N 2 =n 2 r 2 where r 2 ≧1 and n 2 ≧1 and are integers and m middle stage switches where m is an integer and each middle switch has at least one link connected to each input switch and at least one link connected to each output switch, where ##EQU9## and where min{n 2 -1,r 2 } equals the smallest of either n 2 -1 or r 2 , and min {(n 1 -1)x+(n 2 -1)r s 1/x } is the smallest integer solution of {(n 1 -1)x+(n 2 -1)r 2 1/x } said middle stage of m switches having I inputs where I≧r 1 and is an integer, and J outputs, where J≧r 2 and is an integer, x or fewer of the m switches, where 1≧x≧min{n 2 -1,r 2 } and is an integer, always available to form a connection between an idle input port and a plurality of idle output ports, but no output port is connected to more than 1 input port and the m middle stage switches in communication with the input and output stage switches comprising: means for determining which middle stage switches of the m middle stage switches where ##EQU10## have an idle link to the input switch where a broadcast connection request arises and idle links to the output switches in the broadcast connection at a given time in the network; and means for choosing middle stage switches from only the middle switches which have an idle link to the input switch where the broadcast connection request arises and idle links to the output switches in the broadcast connection to form the desired broadcast connection between an idle input port and a plurality of idle output ports without any rearrangement of existing connections between an idle input port and a plurality of idle output ports.