Inventor
SHIRAGAKI TATSUYA
JP16 patents
⚠️ This page may combine multiple inventors who share the name “SHIRAGAKI TATSUYA”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
NEC CORP
15 patentsUS6115517ASep 5, 2000
Optical communication network apparatus and optical switching network
NEC CORP92 citations98
US5457556AOct 10, 1995
Optical cross-connect system with space and wavelength division switching stages for minimizing fault recovery procedures
NEC CORP208 citations98
US6657952B1Dec 2, 2003
Ring network for sharing protection resource by working communication paths
NEC CORP109 citations97
US6023452AFeb 8, 2000
Network failure restoration method with different recovery performances for different signal groups
NEC CORP71 citations96
US5757526AMay 26, 1998
Optical communication network and method for optically detecting a fault
NEC CORP54 citations96
US5663820ASep 2, 1997
Optical network using multiplexed payload and OAM signals
NEC CORP84 citations96
US5471332ANov 28, 1995
Hitless switching apparatus and method for optical network
NEC CORP59 citations95
US7280470B2Oct 9, 2007
Ring network for sharing protection resource by working communication paths
NEC CORP23 citations92
US6785473B1Aug 31, 2004
WDM network and WDM network device
NEC CORP22 citations92
US6538779B1Mar 25, 2003
Optical signal monitoring method and apparatus
NEC CORP30 citations92
US6128115AOct 3, 2000
Optical switch device
NEC CORP36 citations92
US6125104ASep 26, 2000
Network node for switching quality detector to incoming signal specified by request message from adjacent node
NEC CORP18 citations84
US6211983B1Apr 3, 2001
Optical communication network unit comprising an optical signal converting apparatus and/or an optical signal receiving apparatus
NEC CORP8 citations73
US7515545B2Apr 7, 2009
Signal repeater and switching device, method of detecting connecting relation between signal repeater and switching device and communication system
NEC CORP2 citations62
US7043662B2May 9, 2006
Communication device that performs automatic failure recovery and automatic failure recovery method
NEC CORP5 citations62