4.7.3 S1 and X2 user plane aspects

36.3003GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN)Overall descriptionRelease 17Stage 2TS

The S1 user plane protocol stack for supporting RNs is shown in Figure 4.7.3-1. There is a GTP tunnel associated with each UE EPS bearer, spanning from the S-GW associated with the UE to the DeNB, which is switched to another GTP tunnel in the DeNB, going from the DeNB to the RN (one-to-one mapping).

The X2 user plane protocol stack for supporting RNs is shown in Figure 4.7.3-2. There is a GTP forwarding tunnel associated with each UE EPS bearer subject to forwarding, spanning from the other eNB to the DeNB, which is switched to another GTP tunnel in the DeNB, going from the DeNB to the RN (one-to-one mapping).

The S1 and X2 user plane packets are mapped to radio bearers over the Un interface. The mapping can be based on the QCI associated with the UE EPS bearers. UE EPS bearer with similar QoS can be mapped to the same Un radio bearer.

Figure 4.7.3-1: S1 user plane protocol stack for supporting RNs

Figure 4.7.3-2: X2 user plane protocol stack for supporting RNs