As we are moving towards adopting virtualization technologies for next generation mobile networks, 5G base station (called gNB) is segregated into a Radio Unit (RU), a Distributed Unit (DU), and a Central Unit (CU) in order to support Cloud based Radio Access Networks (C-RAN) where RU and DU are connected through a fronthaul link while CU and DU are connected through a midhaul link. Although virtualization of CU gives benefits of centralization to the operators, there are other issues to be solved such as optimization of midhaul bandwidth and computing resources at edge cloud and central cloud where the DUs and CUs are deployed, respectively. In this paper, we propose a dynamic functional split selection for the DUs in 5G C-RAN by adopting to traffic heterogeneity where the midhaul bandwidth is limited. We proposed an optimization problem that maximizes the centralization of the C-RAN system by operating more number of DUs on split Option-7 by changing the channel bandwidth of the DUs. The dynamical selection of split options among each CU-DU pair gives 90% centralization over the static functional split for a given midhaul bandwidth.

翻译：随着我们逐步为下一代移动网络采用虚拟化技术,5G基站(称为GNB)被分成一个无线电股(RU)、一个分布式股(DU)和一个中央股(CU),以支持基于云的无线电接入网络(C-RAN),在这个网络中,RU和DU通过正面连接连接,而CU和DU则通过中间连接连接。虽然CU的虚拟化给操作者带来集中化的好处,但还有其他问题有待解决,例如在部署DU和CU的边缘云和中央云中优化中层带宽和计算资源。在本文件中,我们建议对5G C-RAN的DU进行动态的功能分割选择,在中层带宽有限的地方采用交通异性。我们提议了优化问题,通过改变DU和DU的频道带宽带宽,使更多的DU在分化方面运行更多的DU,从而最大限度地实现C-RAN系统的集中化。我们提议通过改变DU的频道带宽度带宽度,对每个DU-DU的带宽度进行动态选择,对每个带宽段进行90%的分置。