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一、数字程控用户小交换机的发展与未来1985年以前的数字程控用户小交换机(PABX)主要用于话音交换,约占通信业务量和投资费用的90%。但是1985年以后,情况发生了很大的变化,用户要求综合话音/数据PABX的呼声越来越高,例如,美国的用户从1986年开始80%以上的PABX招标规范要求话音/数据综合性能,而且不少用户已经安装了综合话音/数据PABX。在欧洲约1%的小交换机用户线已经实现了综合交换,目前在中国很多PABX新用户均提出了综合业务的要求。因此,PABX的发展无论在技术、结构还是在性能等方面将以综合业务为中心。1.综合业务的前景关于PABX综合业务的发展,可分为三个时期来看。第一阶段为1986年以前,此阶段
First, the digital program-controlled user small switch development and future Before 1985, the digital program-controlled small consumer switchboard (PABX) is mainly used for voice exchange, accounting for about 90% of communication traffic and investment costs. However, the situation has changed a lot since 1985, with the voice of the user demanding more and more integrated voice / data PABX. For example, in the United States, more than 80% of PABX tendering specifications from 1986 onwards require comprehensive voice / data performance, And many users have already installed integrated voice / data PABX. About 1% of PBX subscriber lines in Europe have achieved a comprehensive exchange, and many new PABX subscribers in China have put forward the requirements of integrated services. Therefore, the development of PABX will focus on integrated services in terms of technology, structure and performance. 1. Prospects for Integrated Services Regarding the development of PABX integrated services, it can be divided into three periods. The first stage is before 1986, this stage