Sip calling

I would like to know whether asterisk support making outbound call through a sim card.
Eg:- if we need to make an outbound call we need a sip trunking instead of this sip trunk can we connect our cell phone to our asterisk system and make calls through sim card.
I don’t need the dialer. Is there any mechanism available and does asterisk support it.

Thank you.

The easiest way:
Use a GSM-Gateway (there are a lot on the market, just use Your favourite search engine). Form Asterisk-side it’s a sip-peer making it easy to establish and receive calls

Another official supportet way:
Use a CellPhone with Bluetooth and connect it to Asterisk with the help of chan_mobile. Check, wheter the bluetooth-drivers and chan_mobile support the Cellphone You’d like to use.

A third - unsopported - way:
Search the internet for chan_dongle. It works with GSM/UMTS-Sticks which are cconnected to USB. Check the documentation of chan_dongle for supported devices and supported Asterisk-Versions.