1. Voice Call Handover Mechanisms in Next-Generation 3GPP Systems Speaker ： Chi-Ju Chiu Date ： 2009/12/24

2. Outline An Overview of Next-Generation 3GPP System Voice Call Handing With Fallback to 2G/3G IMS-Based Voice Call Continuity Conclusion

3. An Overview of Next-Generation 3GPP System

4. Single-Radio Voice Call Continuity (SR-VCC) Voice calls need to be transferred across service domains and radio access technologies with so called single-radio Mobile Terminals that can not support simultaneous signaling on both E-UTRAN and UTRAN/GERAN radio channels Single Radio voice call continuity and handoff  E-UTRAN and UTRAN/GERAN  E-UTRAN and CDMA2000 1xRTT

5. Voice Call Transfer from E-UTRAN to UTRAN/GERAN

7. Voice Call Transfer From E-UTRAN to CDMA2000 1xRTT

9. Voice Call Handing With Fallback to 2G/3G

12. Conclusion We present and explain these handover mechanisms, and identify the key motivation behind them It is shown that when voice services are supported over E- UTRAN, the so-called SR-VCC mechanisms can be used to seamlessly hand over voice calls to legacy radio technologies  UTRAN, GERAN, and 1xRTT On the other hand, when no voice services are supported over E-UTRAN, CS fallback mechanisms can be used to transfer the user to a legacy radio access that supports conventional voice services over the CS domain