DL - 4G Americas

o Supporting 3GPP2 SMS procedures via 1xIWS to EPS
� E-UTRAN for GERAN/UTRAN
o Forwarding paging request and SMS to the UE
o Directing the UE to the target CS capable cell via appropriate procedure (i.e. PS
handover, RRC release with redirection, CCO w/NACC)
o The configuration of appropriate cell reselection hysteresis at Location Area boundaries
(or across the whole E-UTRAN) to reduce Tracking Area Update traffic
o To facilitate the configuration of TA boundaries with LA boundaries, the E-UTRAN can
gather statistics (from the inbound inter-RAT mobility events of all UEs) of the most
common LAs indicated in the RRC signaling
o Configuration to permit the operator to choose the target “fallback” RAT and frequency
� E-UTRAN for 1xRTT
o Provision of broadcast information to trigger UE for 1xRTT CS registration
o Establish CDMA2000 tunnel between the UE and MME and forward 1xRTT messages
o Directing the UE to the target CS capable cell via appropriate procedure (i.e. RRC
release with redirection or enhanced 1xCSFB procedure with 1xSRVCC based)
o Release of E-UTRAN resources after UE leaves E-UTRAN coverage subsequent to a
page for CS fallback to 1xRTT CS if PS handover procedure is not performed in
conjunction with 1xCS fallback
o Invoking the optimized or non-optimized PS handover procedure concurrently with
enhanced 1xCS fallback procedure when supported by the network and UE, and based
on network configuration
� UE supporting GERAN/UTRAN CSFB
o CSFB procedures for EPS/IMSI attach, update and detach
o CS fallback request/reject and SMS procedures for using CS domain services
� UE supporting 1xRTT CSFB
o 1xRTT CS registration over the EPS after the UE has completed the E-UTRAN
attachment
o 1xRTT CS re-registration due to mobility
o CS fallback request/reject and SMS procedures for using CS domain services
o Includes enhanced CS fallback to 1xRTT capability indication as part of the UE radio
capabilities if it supports enhanced 1xCSFB
www.4gamericas.org February 2011 Page 128