Optical Communications Using mesh and multi-ring methods in the design of survivable wavelength-routed all-optical networks. - Charoenchai Boworntummarat; Pornchai Thanakomsakorn; Wasan Tirasirikul; Lunchakorn Wuttisittikulkij; Sak Segkhoonthod (Eur. Trans. Telecommun., 2005)