Vikas Shokeen

Section # 1 (Evolution of Telephony) · Difference between 2G / 3G –vs- 4G Non-VoLTE –vs- VoLTE Networks · Services in Non-VoLTE 4G Vs VoLTE Networks · The Problem with 4G (Non-VoLTE) Network? Section # 2 (Voice Service Flow) · Call in CS Core 2G / 3G Networks · Call via CSFB where VoLTE is not available along with 4G · Call in VoLTE where both 4G & VoLTE exists Section # 3 (SMS Service Flow) · SMS in CS Network: Using 2G / 3G · SMS over SGs: SMS transit via SGs Link between 4

Sh , Ro , Cx , Rx , Sv , ISC , Mw , Mg , Mi , Mj , Mr / Mr‘ , UT,S1MME , S5/S8 , S10 , S11 , S6a , Gx , Gy , X2 , SGs , S1U , S5/S8 & SGi ,