Читать книгу Mobile Communications Systems Development - Rajib Taid - Страница 148

This interoperation arrangement, Figure 6.13, which is reproduced from TS 23.401 [39], is similar to the one shown in Figure 6.11, except that the legacy GPRS and UMTS SGSN with the Gn interface capability are deployed by the VPLMN operator. Also, both the VPLMN SGSN and the HPLMN PGW are connected through the Gp interface. The roaming user data is routed from the VPLMN S‐GW back to the HPLMN PGW gateway, i.e. a roaming user has access to the HPLMNs services and resources from the VPLMN. The VPLMN S‐GW and the HPLMN PGW are interconnected through the same S8 logical interface; refer to TS 23.401 [39].