Foley & Lardner
Double ring-type local area network system capable of switching transmission paths without interruption
 In a ring-type network system including a plurality of nodes connected by an L-ring and a R-ring, each of the nodes is constructed by a branch unit for branching data to first and second directions, a first delay unit for delaying the data in the first direction by a first delay time period, a second delay unit for delaying the data in the second direction by a second delay time period, a first combiner for inserting the delayed data in the first direction into a first time slot of a data frame on the L-ring, and a second combiner for inserting the delayed data in the second direction into a first time slot of a data frame on the R-ring. Also, each of the nodes is constructed by a first distributor for extracting data from a second time slot of a data frame on the L-ring, a second distributor for extracting data from a second time slot of a data frame on the R-ring, a third delay unit for delaying the data extracted by the first distributor by a third delay time period, a fourth delay unit for delaying the data extracted the second distributor by a third delay time period, and a switching unit for passing one of outputs of the third and fourth delay units. 
NEC Corporation
H H H
H04L H04J H04J
inventional inventional inventional
Masao
Saito