说明：  该手册主要由核心网、无线网、网管和计费等四部分组成，并按照知识点的 难易程度分成：难（***）、中（**）、易（*）等三个级别，包括3G概念、基础 知识、标准、体制和规范等方面知识，在内容上做到专业性和普及性结合，从而 便于不同专业员工的学习。
(The manual consists primarily of core network, wireless network, network management and billing in four parts, and in accordance with the ease of knowledge point is divided into: hard to easy (***), in (**), (*) three levels, including the 3G concept of basic knowledge, standards, institutional and regulatory areas such as knowledge, to be professionally competent in content and popularity with the staff of different professions in order to facilitate learning.)