PPP拨号上网协议栈，通过串口编程，实现PPP拨号网络底层协议以及TCP/IP协议，主要用于GPRS，CDMA，电话拨号等通信领域。-PPP dial-up Internet protocol stack, through serial programming, PPP dial-up network to achieve agreement and the underlying TCP / IP protocol, mainly for GPRS, CDMA, such as dial-up

中国联通SP接入接口协议 (ETIP) -China Unicom SP Access Interface Protocol (ETIP)

基于金仓CDMA短信猫开发的短信猫应用，使用AT协议实现短信发送功能-Based on the development of gold warehouse CDMA SMS cat cat SMS application, use AT protocol sending text messages