GSM07.10规范，串口复用协议。即在一个物理串口上建立多个逻辑连接，从而实现如 在gprs模块上同时进行短信和gprs数据收发同时进行。-GSM 07.10 is a multiplexer protocol specified by ETSI. It operates between a MS and a TE and allows a number of simultaneous sessions over a normal serial asynchronous interface