| 摘要 |
PURPOSE:To ensure the communication capacity by adopting the modulation system with a margin to radio lines between two stations among each of plural stations and decreasing the communication capacity of a line if the line is deteriorated, and transmitting the decreased capacity through other lines. CONSTITUTION:The modulation system giving a margin to the communication capacity between all two stations among plural stations,e.g., node stations A-D. If a line between the nodes A and B is deteriorated, the transmission capacity of the line is lowered, but the required C/N is decreased to ensure the maintenance of the line and the decreased line capacity is covered by the lines A, D, B or A, C, D through the other nodes. Thus, a standby line such as an optical cable is not required and the installation cost is lowered. This system is suitable to recover the reduction in the transmission capability due to the meteorological condition or a production of an obstacle. |
