NGN－3G核心部件SGSN的代码实现，适合初学者学习，有详细的说明

用Java编写的GPS监控系统后台私服的核心代码。-Using Java to prepare the background of the GPS monitoring system私服the core code.

手机短信收发程序的原代码，其中包括了一些基本的收发程序的核心代码和实现-Procedures to send and receive SMS source code, including some of the basic procedures of the transceiver and the realization of the core code

GPS软件接收机的源码，实现信号跟踪、捕获、电文解调、定位解算等功能，有助于学习卫星导航的同学加深对GPS接收机工作原理的理解，也可作为核心代码扩展为GPS接收机工作原理演示程序。-The source code of the software GPS receiver signal tracking, capture, message demodulation, position resolution and other functions, help students to learn sa