Section: D.2.2 Non-roaming interoperation scenario
Content: In the non-roaming scenario the PLMN operates Gn/Gp 2G and/or 3G SGSNs as well as MME and S-GW for E-UTRAN access. Intra PLMN roaming and inter access mobility between Gn/Gp 2G and/or 3G SGSNs and an MME/S-GW are enabled by: - Gn functionality as specified between two Gn/Gp SGSNs, which is provided by the MME, and - Gn functionality as specified between Gn/Gp SGSN and Gn/Gp GGSN that is provided by the P-GW. All this Gn functionality is based on GTP version 1 only. The architecture for interoperation with Gn/Gp SGSNs in the non-roaming case is illustrated in Figure D.2.2-1. Figure D.2.2-1: Non-roaming Architecture for interoperation with Gn/Gp SGSNs NOTE: If the Rel-7 SGSN applies Direct Tunnel there is a user plane connection between P-GW and UTRAN.