摘要
“转型”已成为当今电信业最热门的话题，转型是电信业应对目前面临的种种挑战，摆脱困境，赢得新的发展机遇的必然选择。电信运营企业转型的基本方向是：从主要提供话音连接的服务商向提供包括内容服务在内的综合信息通信服务商转型，从窄带通信向宽带通信转型，从单业务运营商向全业务运营商转型。在转型的大势下，传统的公众电话交换网（PSTN）何去何从是摆在所有传统电信运营商面前的严峻课题。虽然庞大的PSTN依然是许多传统运营商的立身之本，衣食父母，然而其处境已是“英雄末路，江河日下”。据估计，到2009年，全球75％的话音呼出分钟将由移动发起（而在2004年为20％）；全球35％的PSTN用户将停止使用传统固话，而只依靠移动或VoIP业务；PSTN业务收入将降低40％。
“Transformation” has evidently become the hotspot topic in telecom industry, and the transformation has been widely regarded an evitable choice for the industry to confront challenges, rebound from lurch and grab new opportunities. The basic direction for enterprise transformation is： transforming from the service providers mainly offering voice connection to the service provider offering integrated information communication with content service inclusive; transforming from narrow-band to broadband communication; transforming from sole service operator to whole-service operator. Under the universal trend of transformation, where is the outlet for traditional PSTN becomes an austere topic confronting all conventional telecom operators. Although massive PSTN is still the cash cow for many traditional operators, its withered future has been widely envisaged. According to statistics, by 2009, 75% of global voice call minute will be initiated by mobile （in 2004, the number is only 20%）; and 35% PSTN users worldwide will cancel permanently the traditional fixed line service, turning to rely on mobile or VolP service; consequently,
