D.1 General Considerations

23.4013GPPGeneral Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) accessRelease 18TS

This annex specifies interworking between the EPS and 3GPP 2G and/or 3G SGSNs, which provide only Gn and Gp interfaces but no S3, S4 or S5/S8 interfaces, i.e. these Gn/Gp SGSNs provide no functionality that is introduced specifically for the EPS or for interoperation with the E-UTRAN.

Interoperation scenarios for operating E-UTRAN with a PLMN maintaining Gn/Gp SGSNs are supported only with a GTP-based S5/S8.

NOTE: PMIP-based S5/S8 may be used, but does not support handovers between the Gn/Gp SGSN and MME/S‑GW.

The S5/S8 interface for the Operator with Gn/Gp SGSNs will be GTP-based, but can be changed to PMIP-based S5/S8 when the Gn/Gp SGSNs evolve to S4 SGSNs.

For these interoperation scenarios the GERAN/UTRAN has to support interoperation with E‑UTRAN.

TS 23.682 [74] defines the Monitoring Events feature, and TS 23.060 [7] specifies that the Monitoring Events feature for the Gn/Gp SGSN is not supported. Therefore, during interoperation with Gn/Gp SGSNs Monitoring Event information shall not be expected by the MME/S4-SGSN from a Gn/Gp SGSN, nor shall the MME/S4-SGSN or the HSS transfer Monitoring Event information to a Gn/Gp SGSN. This applies to all operations defined in this annex.