Patent ID: 6141318
Filing Date: 2000-10-31
Classification: H04L

Abstract:
A network design method for use in a network having a plurality of nodes each terminating a path or each being a junction on the path and having a plurality of links each accommodating said path, the method comprising the steps of:providing a plurality of combination candidates of a first to an N-th path for a demand pair composed of a pair of said nodes, N being an integer of at least 2 and said demand pair having a demand capacity;solving a mathematical programming problem which comprises:indicators as variables each indicating whether or not each of said demand pairs uses each of said combination candidates as a combination of a current path and any one of first to (N-1)th standby paths in one or more time zones and in each direction,a first constraint under which a total of said indicators for each of said combination candidates is 1 in said demand pair, in said one or more time zones, and in each of said directions,a capacity to be assigned to said current path accommodated by each of said links, when said current path is not affected by a failure on said network in said one or more time zones, in each of said directions, and in a normal state and each failure state of said network,a capacity to be assigned to said first standby path accommodated by said link, when said current path corresponding to said first standby path is affected by a failure on said network,a capacity to be assigned to said n-th (n=2, . . . , N-1) standby path accommodated by said link when said current path corresponding to the nth standby path and said first to (n-1)th standby paths are affected by a failure on said network, where N is an integer of at least 3, anda second constraint under which a total of the capacity of said current path accommodated by said link and capacities of said first standby path to (N-1)th standby path for said demand pair does not exceed a capacity assigned to said link; anddetermining a combination of said current path, any one of said first standby path to said (N-1)th standby path, and a capacity to be assigned to each of said links, for use by each of said demand pairs, in said one or more time zones and in each of said directions, based on a solution of said mathematical programming problem.