Patent ID: 7280755

Claim:
A highly utilizable protection mechanism for WDM mesh network comprising of; a step of waiting randomly generated channel request which is a request to generate channel between source node and target node, a step of finding shortest path set within limit of hop length, a step of finding disjointed path set for each path of the shortest path set, a step of making pairs using shortest path set and disjoint path set for WP and BP, a step of calculating cost by using cost function considering current network state, a step of sorting the cost lists from minimum cost to maximum cost, a step of selecting best pair having minimum cost, and a step of checking whether each link has enough capacity to allocate channel resources for the channel request with best working and backup path pair having minimum cost, wherein said step of calculating cost is as follow; Cost*=( W 1 ×AC+W 2 ×( WC+BC )+ W 3 ×CC ) where W 1 <<W 2 <<W 3 , W j is much bigger than W i , i<j, i={1, 2,} and j={2,3} where A ⁢ ⁢ C ⁢ = [ ∑ i ∈ WP ⁢ ∑ j ∈ BP ⁢ ( R Allocated i + R Allocated j ) ] Average where R Allocated is average rate of previously allocated wavelengths compared to total link capacity in the links passed by WP or BP, where BC = min j ⁢ ( BR j - SBR j ) , j = 1 , … ⁢ , W , where BR j is required number of wavelengths for BP reservation in the jth wavelength number, SBR j is the number of sharable wavelength for BP reservation in the jth wavelength number, where CC (Capacity Cost)=1 if there is no more wavelength to allocate on a link which WP and BP pass by, where WC (Working path Cost) means the cost of reserving working path.