Telecom Interview Question:

Explain gsm call flow for MS to SMS? and GSM call flow fro MS to roaming MS?

Submitted by: Administrator

First SMS is submitted to SMSC. than it is forwarded from
there to SMS gateway. SMS Gateway retrrives Routing info
from HLR and send it to MSC. MSC gets current location from
VLR of receipent mobile and delivers Msg.
Submitted by: Administrator

When A sends a message to B it will send to serving MSC which contain SMSC address.(SMSC details are store in your SIM card )
MSC then send message to SMSC which store message and get details of B from HLR based on MSISDN. HLR provide routing info and serving MSC detail of B to SMSC.
based on routing info SMSC deliver the message to serving MSC of B and MSC forwarded it to B.
Submitted by: Vaibhav