Antonelli, Terry & Wands
Transmission control system
 A transmission control system for a transmission system including a plurality of transmission lines inclusive of closed loops has a plurality of network control processors (NCPs) and devices connected thereto, respectively. Upon issuing of data by a device, an identification code, such as identification number or code allocated inherently to the, is added to the data to be sent to the associated NCP connected to that device, while upon reception of data from the associated NCP, the identification code is checked to avoid duplicate reception of the same data. Also, inter-networking devices may be provided to check the duplicated relaying of the same data between loops. To this end, the transmission control system includes a plurality of transmission lines, a plurality of devices connected to the plurality of transmission lines, respectively, and interconnecting units for interconnecting the plurality of transmission lines through the devices. Each of the devices operates to send out onto the transmission line a message including data generated by the device and to which is added an identification code for identifying the data, and to store the identification code contained in a message upon reception thereof from the transmission line. Upon reception of a message from one of the connected transmission line, the interconnecting unit transmits to the other connected transmission line the message having the identification code which does not coincide with the identification code having been stored before reception of the message from the one connected transmission line. 
Hitachi, Ltd.
H
H04L
inventional
Yasuo Masayuki Kinji
Suzuki Orimo Mori