1、短信的协议架构

        如下图，参考3GPP 23.040 4.9节 Protocols and protocol architecture

1、SM-AL : 应用层

2、SM-TL ：传输层

3、SM-RL ：中继层

4、SM-LL ：链路层

由于我们只关注手机终端，因此只需要关注SM-TL这一层即可

2、SM-TL分类

短信的协议架构参考3GPP 23.040 PDU Type repertoire at SM-TL

The SM-TL comprises the following six PDUs:
SMS-DELIVER, conveying a short message from the SC to the MS;
SMS-DELIVER-REPORT, conveying;
    a) a failure cause (if necessary); 
    b) information as part of a positive or negative acknowledgement to an SMS-DELIVER or SMS-STATUS-REPORT; 
SMS-SUBMIT, conveying a short message from the MS to the SC;
SMS-SUBMIT-REPORT, conveying; 
    a) a failure cause (if necessary);
    b) information as part of a positive or negative acknowledgement to an SMS-SUBMIT or SMS-COMMAND; 
SMS-STATUS-REPORT, conveying a status report from the SC to the MS;
SMS-COMMAND, conveying a command from the MS to the SC.

相关类型有上面六种
SMS-DELIVER   ---  短信的接收
SMS-DELIVER-REPORT   --- 短信的接收报告
SMS-SUBMIT   ---   短信的发送
SMS-SUBMIT-REPORT   ---   短信的发送
SMS-STATUS-REPORT  --- 状态报告

3、短信的发送

        参考3GPP 23.040 SMS-SUBMIT Type介绍

SMS-        SUBMIT数