Unidirectional Path Switched Ring (UPSR)
UPSR stands for unidirectional path switched ring. This is a type of ring technique that was original developed for SDH/SONET networks. The technique however has been extensively used for new types of optical transport networks such as WDM rings, Optical Transport Network (OTN) ring, Carrier Ethernet ring, etc. As shown in Fig. 1(a), a UPSR [...]