Flexible and Efficient DSP-assisted Subcarrier Multiplexing for an Analog Mobile Fronthaul

The digital formation of an analog subcarrier multiplex employing in combination both a technique using pre-IFFT frequency-domain samples and one using post-IFFT time-domain samples is proposed and demonstrated. This combined technique enables a compromise for sampling rate requirements, while maintaining low complexity and good performance

End-to-End Provisioning of Latency and Availability Constrained 5G Services

We address a key challenge of 5G networks by proposing a strategy for the resource-efficient and end-to-end allocation of compute and connectivity resources in a dynamic 5G service provisioning scenario, such that the service latency and availability requirements are guaranteed. Our heuristic algorithm shows that resource efficiency is significantly improved by processing services in the large core data centers (DCs) with a rich amount of compute resources and exploiting the benefits of traffic grooming over the metro and core fiber links. Moreover, our resource-efficient provisioning algorithm avoids possible violation of the service availability requirements caused by reaching the central DC locations by adding backup connectivity resources. Our simulation results demonstrate a resource efficiency improvement reflected by lowering the service blocking probability by up to four orders of magnitude compared to the conventional service provisioning methods utilizing distributed small DCs

On the Optimization of Multi-Cloud Virtualized Radio Access Networks

We study the important and challenging problem of virtualized radio access network (vRAN) design in its most general form. We develop an optimization framework that decides the number and deployment locations of central/cloud units (CUs); which distributed units (DUs) each of them will serve; the functional split that each BS will implement; and the network paths for routing the traffic to CUs and the network core. Our design criterion is to minimize the operator's expenditures while serving the expected traffic. To this end, we combine a linearization technique with a cutting-planes method in order to expedite the exact solution of the formulated problem. We evaluate our framework using real operational networks and system measurements, and follow an exhaustive parameter-sensitivity analysis. We find that the benefits when departing from single-CU deployments can be as high as 30% for our networks, but these gains diminish with the further addition of CUs. Our work sheds light on the vRAN design from a new angle, highlights the importance of deploying multiple CUs, and offers a rigorous framework for optimizing the costs of Multi-CUs vRAN.Comment: This preprint is to be published in Proc. of IEEE International Conference on Communications (ICC) 202

Sharing gNB components in RAN slicing: A perspective from 3GPP/NFV standards

To implement the next Generation NodeBs (gNBs) that are present in every Radio Access Network (RAN) slice subnet, Network Function Virtualization (NFV) enables the deployment of some of the gNB components as Virtual Networks Functions (VNFs). Deploying individual VNF instances for these components could guarantee the customization of each RAN slice subnet. However, due to the multiplicity of VNFs, the required amount of virtual resources will be greater compared to the case where a single VNF instance carries the aggregated traffic of all the RAN slice subnets. Sharing gNB components between RAN slice subnets could optimize the trade-off between customization, isolation and resource utilization. In this article, we shed light on the key aspects in the Third Generation Partnership Project (3GPP)/NFV standards for sharing gNB components. First, we identify four possible scenarios for sharing gNB components. Then, we analyze the impact of sharing on the customization level of each RAN slice subnet. Later, we determine the main factors that enable isolation between RAN slice subnets. Finally, we propose a 3GPP/NFV-based description model to define the lifecycle management of shared gNB componentsComment: Article accepted for publication in IEEE Conference on Standards and Networking (CSCN) 201