Evolved Universal Terrestrial Radio Access Network (E-UTRAN) or RAN side (LTE side) consists of eNode B nodes. eNodeB nodes are are connected to each other via the X2 interface. Both the S1 and the X2 interface can be divided into control plane and user plane
The S1 and X2 are multi-to- multi capable interfaces meaning that one eNode B can be connected to multiple MMEs , S-GW and other e-Node Bs.
However a UE can only be connected to one eNodeB , MME and S-GW at a given moment. Two terminals connected to the same eNodeBs can be connected to difference SGWs and vice versa.