北京电信引进美国ＡＴ＆Ｔ光同步数字传输系统和网管系统的合同已签５月７日，管理局利用美国ＡＴ＆Ｔ公司贷款引进光同步数字系统（ＳＤＨ）和网管系统合同正式签约。参加签字仪式的有邮电部副部长林金泉、北京市政府及各主管部门的负责人、中国邮电器材总公司副总裁潘连... Beijing Telecom’s contract to introduce the AT & T optical synchronous digital transmission system and network management system in the United States has been signed. On July 7, the Authority formally signed an agreement on the introduction of an optical synchronous digital system (SDH) and a network management system using loans from the U.S. AT & T Company. At the signing ceremony, Lin Jinquan, vice minister of the Ministry of Posts and Telecommunications, Beijing Municipal Government and heads of various departments in charge, Pan Lian, vice president of China Posts and Telecommunications Equipment Corporation ...