DL - 4G Americas

� Inter-RAT Handover (UTRA to HeNB and LTE to HeNB)
� Enhancements to Existing Mobility Mechanisms for HeNB Cells
� Footprint Accuracy Improvement
� Signaling and UE Battery Minimization
� Inbound Handover Performance Enhancements
� IDLE Mode Improvements for Inter-PLMN CSG Reselection
� Interference Management between HeNB and Macro eNB
� Interference Management among HeNB
7.3.2 LIPA/SIPTO
3GPP had requirements on Local IP Access to the home and Internet in Rel-9 but those features were
not completed as part of Rel-9 and the work was moved to Rel-10. Due to the fact that 3GPP radio
access technologies enable data transfer at higher data rates, the 3GPP operator community shows
strong interest in offloading selected IP traffic not only for the HeNB Subsystem but also for the macro
layer network (i.e. offload selected IP traffic from the cellular infrastructure and save transmission costs).
From a functional and architectural perspective, the issues for selected IP traffic offload are similar for
HeNB Subsystem and for macro layer network and therefore there are commonalities with regard to
architecture decisions.
Support of Local IP access for the HeNB Subsystem, selected IP traffic offload for the HeNB Subsystem
and for the macro layer network is required in 3GPP TS 22.220 and TS 22.101. The following
functionalities are being defined:
� Local IP access – LIPA – to residential/corporate local network for HeNB Subsystem
� Selected IP traffic offload – SIPTO– (e.g. Internet traffic) for HeNB Subsystem
� Selected IP traffic offload (Internet traffic, corporate traffic, etc.) for the macro network (3G and
LTE only)
www.4gamericas.org February 2011 Page 66