Mobile Call Origination in GSM
1.The MS sends the dialed number indicating service requested to the MSC (via BSS)
2.The MSC checks from the VLR if the MS is allowed the requested service. If so MSC asks BSS to allocate necessary resources for the call
3.If the call is allowed ,the MSC routes the call GMSC
4.The GMSC routes the call to the local exchange called user.
5.The LE alerts (applies ringing) the called terminal 6. Answer back (ring back tone) from the called terminal to LE
7.Answer back signal is routed back to the MS through the serving MSC which also completes the speech path to MS