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在1988年7月举行的苏联邮电部科学技术委员会会议上,讨论了中央邮电科学研究院关于(?)-120-4/5型成套设备国家试验结果的报告。与会者有各方面的专家。 (?)-120-4/5型二次群数字传输系统成套设备,供干线线路采用单缆和双缆传输的市话网高频对称电缆(7×4×1.2和4×4×1.2)和光缆工作之用。采用这种设备后,通过利用速率每秒2048千比特的同步(异步)或混合式四个一次群数字流组合可以建立120路音频信道;或者采用把模拟传输系统标准60路的
At a meeting of the Soviet Ministry of Posts and Telecommunications Science and Technology Commission held in July 1988, the report of the Central Research Institute of Posts and Telecommunications on the national test results of (?) - 120-4 / 5 complete sets of equipment was discussed. Attendees have various experts. (?) - 120-4 / 5 type secondary group digital transmission system equipment for high-frequency symmetric cable (7 × 4 × 1.2 and 4 × 4 × 1.2) Optical cable work purposes. With this equipment, up to 120 audio channels can be established by using a combination of synchronous (asynchronous) or mixed four primary-group digital streams at a rate of 2048 kilobits per second; or using standard 60-channel analogue transmission systems