Hello community,

I have a question about channels/connections involved in multiple cell attachement/transmission:

For basic CoMP mechanism, for example DPS ( Dynamic point selection),  the UE at an instant is attached to his serving cell, and the PDSCH channel for a selected Transmission point is transmitted to the UE. Since i didn't find clair documentation about CoMP, I set up two possibilities:

First Possibility : For DPS, every T subframe, the Transmission point from the coordinating set of the UE, that will serve the PDSCH data to the UE, will be selected dynamically according to the change of csi of the UE to the multiple coordinating eNodeBs. So depending on the backhaul requirements for bw and latency, the UE will establish a new RRC connection when a TP is dynamically selected ( the serving cell change). So we will establish the RRC connection each T subframe to deliver data to it.

Second Possibility : For the DPS, The serving cell with the one for which the UE is attached, will not change since the UE still in his coordinating area. And the TP that will deliver the PDSCH data will be selected dynamically just to send physical channels and still the serving cell the one that control the transmission of neighboring cell, only the serving cell that select the physical transmission ( TP) but the RRC connection is maintained only with the serving cell. even in case of joint transmission how can multiple PDSCH channels can be transmitted to the UE at the same time, if there is no RRC connection to the multiple cells. 

Please can someone help me to assess my analysis, What about RRC connection from UE to the multiple coordinating cells ( First possibility) . And transmission of PDSCH data without RRC connection with the transmitter ( second possibility ) ??

Best Regards!