3GPP 23.040 电信文档，介绍短息格式-3GPP 23.040 Telecom documents, introduce short message format

这是gsm模块发短息的程序，可以实现gtm900向外发短信的功能，后续的功能可以在此基础上增加-This is a hair short interest gsm module program, you can achieve gtm900 outward texting function, subsequent function can be increased on the basis of