lost sms

Hi I built the luca/gsmmap branch, and saw many messages in the wireshark with protocol GSM_SMS; but when I tried to capture my sms (sending by my own phone), it does not work, I can not see my sms in wireshark; then I used another phone to send a message to my phone, I saw nothing in wireshark too; Could anyone tell me why? Is it a problem about time slot ? Regards, Swift changchuan618(a)gmail.com