Patent ID: 6904047

Claim:
A method for cell scheduling in an input and output buffered ATM switch having input ports and output ports and using simple iterative matching, the method comprising: a request step, wherein when one of unmatched FIFO queues Q(i, j) has an HOL cell, each of unmatched input round-robin pointers A(i, h) sends a request signal to output round-robin pointers G(j, h); a grant step, wherein when a unmatched output round-robin pointer G(j, h) receives said request signal, said unmatched output round-robin pointer G(j, h) searches said request signal from g(j, h)-th element of said request signal and selects the nearest request, grants the request and notifies the grant of the request to each of input round-robin pointers A(i, h); and an accept step, wherein when the unmatched input round-robin pointer A(i, h) receives said grant signal, said unmatched input round-robin pointer A(i,h), searches from a(i, h)-th element of said grants, and selects the nearest grant to accept transmission, and when more than two input round-robin pointers among A(i,h) having the lowest h value, said unmatched input round-robin pointer A(i,h) accepts transmission with respect to the FIFO queue, wherein said input round-robin pointer A(i, h) is allocated to an i-th input buffered module and is assigned to the h-th switching plane, said output round-robin pointer G(j, h) is allocated to a j-th output buffered module and is assigned to the h-th switching plane, a(i, h) is an element for which said input round-robin pointer A(i, h) first attempts matching and g(j, h) is an element for which output round-robin pointer G(j, h) first attempts matching, and wherein i=1, . . . , m, j=1, . . . , m, h=1, . . . , n, and m is a number of input and output buffered modules, and n is a total number of switching planes.