Vikas Shokeen

Section # 1 (Evolution of Telephony) · Difference between 2G / 3G –vs- 4G Non-VoLTE –vs- VoLTE Networks · Services in Non-VoLTE 4G Vs...

RSR : Registration Success Ratio (%) - CSSR : Call Setup Success Rate (%) - CST : Call Setup Time (s) - MHT/ACD : Average Call duration (s)

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 ,

Single Radio Voice Call Continuity (SRVCC) - CSFB (circuit switched fallback) - PS to CS handover - CSFB Vs SRVCC - SRVCC , aSRVCC , eSRVCC

SIP Call Flow - Mobile Originating (MO) & Terminating (MT) - INVITE - 100 Trying - 183 Progress SDP - PRACK - 200 OK - UPDATE - 180 Ringing

SIP IMS registration - Default Vs Dedicated Bearer in LTE - SIP and IMS Registration - TAS Registration - QCI-1 ( Voice ) , QCI-5 (SIP)

VoLTE IMS Architecture - SIP Handset , Underlying LTE Network , IMS Core - SIP Servers , P-CSCF , I-CSCF , S-CSCF , TAS , MMTEL , BGw , MRF

Network Evolution to VoLTE , VoLTE - Benefits for Users , Operators . VoLTE Challenges & Handling Congestion Scenarios