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一般趋势当前,大多数国家的电话网是模拟的。这是因为电话信号是一种连续的模拟信号,因此,在其发展初期很自然地采用模拟技术来传输和交换电话信号,并在发展中,逐步占了主导地位。1962年,美国研制成功了脉冲编码24路设备,于是数字传输技术开始在模拟网中与模拟传输技术展开了竞争,并取得了节节胜利。 1969年,法国首先采用了E10数字交换机,并在拉尼翁地区把数字传输与数字交换结合在
General Trends Currently, the telephone network in most countries is modeled. This is because the telephone signal is a continuous analog signal. Therefore, it is natural to use analogue technology to transmit and exchange telephone signals in its early stage of development and gradually take the lead in the development. In 1962, the United States successfully developed the pulse code 24-channel equipment, so digital transmission technology began to compete with the analog transmission technology in the analog network, and achieved success. In 1969, France first adopted the E10 digital switch and combined digital transmission and digital exchange in the Lannion region