Mobile networks have evolved towards heterogeneous networks, with multiple radio access technologies, densified multi-layer cell deployment, flexible spectrum access, elastic capacity and highly energy efficiency. The traditional cell concept in future mobile networks will disappear as wireless network resources have to be utilized harmonically in the same area by different network entities. Those network entities could be base stations, access points, user device, relays and others. Therefore, the efficient coordination among the network and potentially user devices would be a key factor for the success of 5G mobile networks. However, efficient solutions capable of dealing with increasing complexity in 5G networks are yet to come.
The optimal resource utilization in heterogeneous mobile networks has been a challenge problem. Recall that even the frequency assignment problem in Global System for Mobile Communications (GSM) networks is difficult, not to say the multi-dimension resource allocation in complex heterogeneous mobile networks. Distributed solutions are scalable and flexible, but often yield sub-optimal results far away from the expectation. Centralized solutions have potential to achieve the global optimal, but coming with high cost on signalling and latency.
Indeed, we need innovations to deal with the control and coordination problem in large-scale heterogeneous mobile networks, so as to release the full potential of 5G networks. The key enabler to achieve such goal lies in the proper separation of control and data plane, common control protocols, interfaces and primitives for network coordination and automation, and efficient resource allocation and spectrum management in the network. These are key aspects to be investigated by COHERENT.
The aim of COHERENT is to design, develop and showcase a simple, open, unified and programmable control framework, and interact with other 5G Infrastructure Public-Private Partnership (PPP) projects to enable a unified control and management framework for 5G integrated networks.