GSM协议中BCCH码道的层2和层3解析。包括接收层1的消息，到层2解析后发给层3的处理，最终层3解析后进行打印。-GSM protocol layers 2 and 3 of the BCCH code channels to resolve. Including receiving layer messages 1 to layer after layer processing 2 parsed issued 3 final layer printed 3 resolution.