P-CSCF restoration enhancements for WLAN
The present document analyses P-CSCF restoration enhancements for WLAN. After reviewing existing P-CSCF restoration with their limitations, it defines the objectives to fulfil and proposes solutions addressing trusted WLAN using S2a interface and untrusted WLAN using S2b interface. The enhancements refer to and complement the HSS based and PCRF based solutions for 3GPP accesses specified in Rel12 and described in 3GPP TS 23.380 [2].