一、交换技术发展简况电话发明至今已有100多年历史了。交换技术在不断地向前发展，特别是近20年来，随着微电子技术、计算机技术的飞速发展，交换技术得到空前的进步。交换技术经历了人工交换（磁石式、供电式）到自动交换的过程。从以下几个方面我们可以看出自动交换技术的发 First, the exchange of technology development profile Telephone has been more than 100 years of history. Exchange technology is constantly moving forward. Especially in the recent 20 years, with the rapid development of microelectronics and computer technology, exchange technology has made unprecedented strides. Exchange technology has experienced a manual exchange (magnet type, power supply type) to the process of automatic exchange. From the following aspects we can see the development of automatic exchange technology