LTE : Can MME decides who are the neighbor ENBs of a particular ENB?

Question

I just thought of a situation ,

As each ENB does S1 connection with MME.so consider 3 ENBs(those are nearer to each other) did S1-Setup with a particular MME.

After S1-Set up done can we have/add some intelligence (Based on some identity ) at MME to know who all are neighbor for whom?

If we will know about this we can make X2 -relation with neighbor easily ,so that we can reduce the overhead of getting info of neighbor ENBs.

Answer 1

I think SON covers all those things :). An eNodeB decides about its neighbor based on radio coverage of its neighbor. LTE has introduced X2 interface to make handover faster. Suppose there are two enodebs (i.e. eNodeB1 and eNodeB2).

MME tells to eNodeB1 that eNodeB2 is your neighbor but assume they are not overlapping then how would handover be proceed ?

So it better to keep these things at eNodeB and let the eNodeB decides who is your neighbor since these things may change dynamically.

Comments

ENB1 can decide who is neighbor based on UE Measurement , But it is time taking so the requirement comes that can MME know that the ENB1 and ENB2 is nearer.

Can  u tell me one thing based on TAI can we know who are all the neighbor of an ENB ?

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When you say "can WE know who are the neighbor of an ENB" , by WE you are referring to whom ?? UE or ENB .

If UE , then you will get a tracking area list which is a superset of the neighbors.

If you mean ENB, then the neighbor ENB list is already configured in every ENB. ENB never interprets TAI or TAU message

Answer 2

If you talk about the handover use case , it is the eNB who has to decide the neighbor cell ( based on measurement reports or X2 connections or neighbor cell info database ) . Here MME does not have a role to play.

If you are talking about the load balancing scenario from MME's perspective then yes MME needs to know the neighbor cells of a particular eNB cell. This is part of the MMEs provisioning.