LTE Tutorials

LTE Protocol Stacks

The figures below diagram the key protocol stacks on Uu, S1, and X2 interfaces for both C-plane and U-plane messaging.

Figure 1 :  C-plane Protocol Stack: Uu (UE/eNB) and S1-C (eNB/MME)

Figure 2 :  C-plane Protocol Stack: X2-C (eNB/eNB)

Figure 3 :  U-plane Protocol Stack: Uu (UE/eNB) and S1-U (eNB/S-GW)

Figure 4 :  U-plane Protocol Stack: X2-U (eNB/eNB)