６８Ｍｂ／ｓ数字微波改造中的几个技术问题陈祥凌１９９３年以前，我省的长途微波传输电路，全部是模拟的，无一条数字电路，这就造成了各地、市在大量引进数字程控交换机的同时，又引进了相当数量的ＰＣＭ转换设备．为改变这一落后状况，我们在省局的支持下，用了半年时... 68Mb / s digital microwave transformation in a few technical problems Chen Xiangling Before 1993, the province’s long-distance microwave transmission circuit, all analog, without a digital circuit, which resulted in around the city in the introduction of a large number of digital program-controlled switches at the same time , But also introduced a considerable number of PCM conversion equipment. In order to change this backward situation, with the support of the provincial bureau, we spent six months ...