Select 1. System Introduction 2. The Merits of the Digital System 3. Characteristics and Merits of the System 4. System Specification 5. Example of System Operation 1. System Introduction It is equipment that minimizes distortion and outside noise during transmission by using digital optic transmission technology between donor and remote. By sending digital signals, the system allows re-generation of remote signals and diverse network configuration. Since the signals do not change during transmission, line loss does not occur. Therefore, compensation for line loss in installation or maintenance is unnecessary. As for operations and maintenance, the system is more convenient than analog optic repeaters. By supporting three branches for the donor and extending lower branches and sub-branches, the system can form a wide range of networks.