公开(公告)号：US06259704B1

公开(公告)日：2001-07-10

申请号：US08839227

申请日：1997-04-23

申请人： Takashi Asahina ,  Hiroyuki Hisatomi ,  Suguru Hirono ,  Nobuo Murata

发明人： Takashi Asahina ,  Hiroyuki Hisatomi ,  Suguru Hirono ,  Nobuo Murata

IPC分类号： H04L1243

CPC分类号： H04L12/43

摘要： A digital transmission network comprises a plurality of transmission terminals and receiving terminals, which are all connected with each other by a transmission line of a metal cable or optical fiber cable in the form of loop. Signals are transmitted by timeshare multiplexing in one direction. An individual time slot which is defined for each transmission terminal by time sharing multiplexing is allocated to each of all transmitted signals. A timing device is inserted into the loop for retransmitting a signal so that the delay time is corrected to the delay time of one frame including the delay time caused by the transmission line, cable and the like so that the consecutive frames are continuous. The transmission line is in single or dual loop. In case of the single loop, the transmission terminal includes a bypass circuit for bypassing a signal input to the transmission line if necessary. In case where the transmission line is in a dual loop comprising optical fiber cables of a working line and backup line, a control signal of loop-back is transmitted to all receiving terminals from a receiving terminal which serves as a central unit to bring all receiving terminals into a state enabling signals to be input from the optical fiber cable of the backup line. A control signal is transmitted which returns the receiving terminals into a state enabling signals to be input from the working line in order of proximity to the central unit for confirming that the receiving terminals are normally operating in order of proximity to the central unit.

摘要翻译： 数字传输网络包括多个传输终端和接收终端，这些传输终端和接收终端通过环形形式的金属电缆或光纤电缆的传输线相互连接。 信号通过分时复用在一个方向上发送。 通过时分复用为每个发送终端定义的单个时隙被分配给所有发送的信号中的每一个。 将定时装置插入到环路中以重发信号，使得延迟时间被校正为包括由传输线，电缆等引起的延迟时间的一帧的延迟时间，使得连续的帧是连续的。 传输线处于单回路或双回路。 在单个环路的情况下，如果需要，发送终端包括用于旁路输入到传输线路的信号的旁路电路。 在传输线处于包括工作线路和备用线路的光纤电缆的双回路的情况下，环回控制信号从作为中央单元的接收终端发送到所有接收终端，以使所有接收 终端进入能够从备用线路的光纤电缆输入信号的状态。 发送控制信号，其将接收终端返回到使得能够根据接近中央单元的顺序从工作线路输入信号的状态，以确认接收终端正常按照靠近中央单元的顺序操作。