LTE: What are all parameters exchange between eNodeBs while establishing X2 connection between them ?

Question

Consider Two ENB of two different operator can they establish X2-AP Connection if X2-AP Support is there ???

I guess it is possible as ECGI will give unique identification to them . (Though possibility of CGI is same) ...

is there any other scenario like x2AP- is not possible between them

Answer 1

When an eNodeB setups X2 connection with its neighbor eNodeBs, following information gets exchanged.

X2 SETUP REQUEST message from eNB1 to eNB2:
- Global eNodeB ID of the sending eNodeB
- List of Serving Cell Information (an eNodeB can support up to 256 cells)
- Neighbor Cells Information (an eNodeB can support up to 512 cells)
- List of MME Pool Ids (an eNodeB can have connection with up to 16 MME pools)

--> Serving Cell Information contains information (PCI, ECGI, TAC, list of broad casted PLMNs and running mode (FDD mode/TDD mode) of the cell.

---> Neighbor Cell Information (PCI, ECGI, EARFCN )

---> MME Pool Id consists of PLMN + MME Group Id

X2 SETUP RESPONSE message from eNB2 to eNB1: eNB2 also shares the similar information with the eNB1.

Reference : TS 36.423
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