Impact of Network Densification on Joint Slicing and Functional Splitting in 5G

The virtualization of the fifth generation radio access network (RAN), which distributes the next generation Node B functions between a central unit (CU) and a distributed unit (DU), along with the emergence of slicing as a corner-stone of mobile communications networks, pose new challenges. One of these challenges is the management of the joint slicing and allocation of appropriate distribution of functions between CU and DU, known as functional split. In this work, a discussion on the challenges and open issues of joint slicing and functional splitting is presented, taking into account the additional complexity resulting from instantiating multiple slices per OU, each one with a different functional split. It is shown that the additional complexity, which is translated into higher cost, is worthwhile depending on the RAN deployment density.