The DeNB hosts the following functions in addition to the normal eNB functions:
- S1/X2 proxy functionality for supporting Relay Nodes
- S11 termination and S-GW/P-GW functionality for supporting Relay Nodes.
In order to provide the Relay Function the DeNB shall support the following P-GW functions:
- IP address allocation for the UE functionality of the RN;
- Downlink transport level packet mapping between the DSCP value used over S1-Ui of the UE (which is the SGi interface of the PGW function in the DeNB) and the EPS bearers with an appropriate QCIi value established between the PGW function in the DeNB and the UE function of the RN;
- Uplinki transport level packet mapping between QCI value of the EPS bearers (established between the PGW function in the DeNB and the UE function of the RN) and the DSCP value used over S1-U of the UE (which is the SGi interface of the PGW function in the DeNB).
In order to provide the Relay Function the DeNB shall support the following S-GW functions:
- Termination the S11 session of the MME(RN).
S-GW functions related to ECMi-IDLE are not required.
S-GW functions related to mobility management are not supported.