CA over X2 in LTE

Hi Experts,
Anyone having idea how CA over X2 work in LTE?

One-way delay must be <= 4ms.

It’s inter site CA.
Pcell RLC send packets to scell MAC for scheduling over X2 link.

Our nw it’s < 10ms.

Ok so let’s say I have 2 nodes but sector 1 radiate from same multi band antenna of each node.
Then I think for CA working still CA over X2 required as nodes are different.

If both cells are not served by same DU (same scheduler) then yes, it’s over X2.

It’s LTE so no DU/CU, only eNodeB.

DU is digital unit in LTE.
Other vendors may have different name, but just consider nw element which handles scheduling part.

DU distributed unit.
CU central unit.
Good to know DU in LTE as well called Digital Unit.

for Nokia ,There is allowed up to 20 ms one-way delay on X2 link between remote eNBs hosting PCell and related SCell(s)

It is possible to aggregate cells hosted by remote eNBs connected with X2 links (inter-site CA) .