如何使用gammu短信检测来电？

I'm using Gammu for SMS Gateway

I use php to implement.

I use wavecomm modem.

Gammu is really useful for everything about SMS.

but I want to detect incoming calls.

how to detect incoming call to the modem?

so, if someone calls to the number in the modem, I want to be notified, or I want to send SMS to the caller, like "sorry this number can't receive any calls"

thanks

Recent Gammu SMSD versions can automatically hangup incoming calls, but there is no finer grained control right now.