Impact of waveband capacity on protected hierarchical optical path networks

The hierarchical optical path network that utilizes wavebands is recognized as very important in meeting the future explosive growth of traffic demand. The use of backup paths is crucial to realize reliable networks. In order to build survivable hierarchical optical path networks, the two types of protection mechanisms implemented in the optical layer are identified: waveband protection and wavelength path protection. We have already developed a novel network design algorithm that utilizes waveband protection and showed that it can reduce network costs significantly. Another type of protection, wavelength path protection, was also developed and we have demonstrated that further network cost reduction can be attained in the area of small traffic demands. The effectiveness of the wavelength path protection algorithm was confirmed for some network parameter values, however, further clarification is necessary regarding the impact on network cost of network parameters, especially waveband capacity, a major network parameter. This paper investigates network cost variation with waveband capacity for hierarchical optical path networks that utilize waveband and wavelength path protection. Numerical experiments demonstrate the importance of waveband capacity optimization.