Section: 5.6 Network Assisted Cell Change
Content: Network Assisted Cell Change (NACC) is a means that enables better performance for packet data services upon inter-cell change for those networks that do not support PS Handover. It reduces the service interruption time for UEs in active mode upon cell change by providing in the source cell, prior to the cell change, system information of a target cell allowing packet access. Within the scope of this specification, NACC is applicable for inter-RAT cell changes from a source E-UTRAN cell towards a target GERAN cell. When the UE changes from a source E-UTRAN cell towards a target GERAN cell, the UE locally deactivates ISR by setting its TIN from "RAT-related TMSI" to "GUTI", if any EPS bearer context activated after the ISR was activated in the UE exists. When the UE changes from a source E-UTRAN cell in connected mode towards a target GERAN cell from the same RA via Cell Change Order that is not for CS fallback and the ISR is active, the UE locally deactivates ISR by setting its TIN from "RAT-related TMSI" to "GUTI".