一个学习AT指令的好东东，而且是中文的，十分详细。

面向通信控制器硬件的通信程序设计：基于PC标准通信口的通信程序设计，基于MODEM的通信程序设计，基于网络适配器的通信程序设计。 网络通信系统的应用实验 -Communication controller hardware-oriented communications program design: Based on standard PC communications port communication program design, based on the MODEM communications programming, network adapter based on the design of communication procedures. Network Communication System Experiment

XMODEM/YMODEM PROTOCOL REFERENCE

ADSL 接入技术已成为终端用户最主要的宽带接入技术。ADSL 技术的关键是ADSL 调制解调器,即ADSL MODEM。ADSL 用户端调制解调器驱动器是一个宽频带功率放大器,他能不失真放大和传输电话线上已编码的数字信号。 本文通过对ADSL 调制解调器驱动器特点、结构和性能的分析,给出了一种ADSL 用户端MODEM 驱动器的实现电路。该 电路采用具有优良高频的双功率放大器L T1886 ,即使在配置高电平的闭环增益网络后也能保持较低的失真。-ADSL access technology has become the most important end-user broadband access technology. ADSL technology is the key to ADSL modem, that is, ADSLMODEM. ADSL modem client driver is a broadband power amplifier, the distortion that he can not enlarge and transfer telephone lines have been encoded digital signal. Based on the ADSL modem driver characteristics, structure and performance analysis, we give a ADSL client realize MODEM driver circuit. The circuit has an excellent high-frequency power amplifier of the dual-L T1886, even though high in the configuration of the closed-loop gain network also able to maintain low distortion.

gprs协议栈代码.所谓协议栈就是对信息进行多次封装和解封的过程，以便能够在不同的实体间传送信息。本源代码来自Indian Institute of Technology-gprs protocol stack code. The so-called agreement is the right information Stack several Packaging, and the course was cleared, to the various entities to disseminate information. Source code from the Indian Institute of Technology

电话拨号程序，附有简易的拨号键盘，能通过modem通话-Telephone dial-up procedures, accompanied by simple dial-up keyboard, through the modem to call

一个完整的短讯网关示例,支持短讯收发,支持UDP及Text格式.-a complete SMS Gateway example, support SMS transceiver to support UDP and Text formats.

e1-framer for developing E-1 modems

调制解调器网络编程，对用的它的人会看看的-modem network programming, it is the right of people will see the

XModem协议源码，众所周知的一个协议的源码，搞arm的第一个程序基本上就是这个-XMODEM protocol source code, as we all know the source of an agreement, to engage the first arm is basically a program that

功能十分强大的拨号程序，可以选择拨号连接，设置拨号参数-function very powerful dial-up procedure, we can choose to dial-up connections, dial-up parameters set