2015/09 20 p.
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 TS 23.380