为了解我国对窄带ISDN业务的近期实际需求和潜在市场，有关部门在京、沪、穗三城市对ISDN业务做了缜密的调查研究。
To understand the real demands and potential market in China for narrow-band ISDN, a meticulous research has been made into the ISDN service requirements in Beijing, Shanghai and Guangzhou.
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