This technical report describes key issues and solutions for optimized offloading of traffic to WLAN access when PS
mobility between 3GPP RAT takes place. The technical report analyzes the user and service impact due to mobility
between 3GPP RATs. The technical report analyzes the key issues and solutions in order to identify whether current
mechanisms documented in SA2 specifications are sufficient, identify potential inefficiencies, and identify whether
additional solutions are needed to address the key issues.
The technical report also describes proposed extensions to ANDSF in order to enable policy differentiation for 3GPP
RATs (e.g. E-UTRAN versus UTRAN, GERAN versus UTRAN) with respect to WLAN, in order to enable a UE to
distinguish preferences of WLAN with respect to specific 3GPP RATs upon acquiring connectivity (e.g. PDN creation
in a 3GPP RAT or WLAN, or establishing NSWO connectivity) or upon mobility.