A Proposal on Network Control Architecture for CoMP JT with IP Network between eNBs

CoMP JT (coordinated multi-point joint transmission) is being discussed in 3GPP (3rd Generation Partnership Project). User data is simultaneously transmitted from multiple eNBs (evolved NodeB) to a UE (User Equipment) to improve the cell edge performance. The important point here is that not only the throughput of the CoMP UE but also the total throughput of the system must be improved by initiating CoMP JT. Therefore a novel network control architecture is required to optimize the total system throughput by initiating or terminating CoMP JT. In this paper, we propose a network control architecture for CoMP JT that works over an IP backhaul network between eNBs. To mitigate the transmission delay of IP packets, two levels of time scale are introduced. The radio resource for CoMP JT is allocated every several hundreds of milliseconds. On the other hand, modulation and coding scheme (MCS) for link adaptation is calculated every millisecond. The proposed network control architecture is working without a central control entity. This distributed architecture is suitable for LTE-A (Long Term Evolution Advanced). It is also possible to eliminate inter-cluster interference with this proposed architecture.