Efficiency gains in 5G softwarised radio access networks

Nikolaos Gkatzios,Dimitra Simeonidou,Markos Anastasopoulos,Anna Tzanakaki

doi:10.1186/s13638-019-1488-z

Abstract

This paper proposes the concept of compute resource disaggregation in centralized softwarised radio access networks. This approach allows individual allocation of processing functions to different servers depending on the nature and volume of their processing requirements. The benefits of the proposed approach are evaluated through experiments analyzing the baseband unit (BBU) processing requirements of LTE PHY using an open source suite for wireless systems and a purposely developed multistage linear programming modeling framework. To address the high computational complexity of integer linear programming (ILP), limiting real-time services, a heuristic algorithm was also developed. Our results show that when using the proposed approach, the overall system power consumption is reduced by 40% under high loading scenarios compared to the traditional solution where all BBU functions are hosted in the same physical servers. The heuristic results achieve relatively good agreement with the ILP results (the gap is less than 5%), particularly for low and high loading conditions. At the same time, the heuristic requires less than 0.3 s to identify the optimal allocation policy.

Highlights

To address the computational complexity of the integer linear programming (ILP), a heuristic algorithm was developed, with the aim to assign the construction elements of the baseband unit (BBU) chain to the suitable servers hosted by the central unit (CU) with minimum power consumption
The increase of mobile traffic predicted in 5G networks as well as the wireless access technology densification and advancements proposed to address this introduces very stringent requirements in the radio access networks (RANs)
The central unit (CU) can be hosted in data centers (DCs) comprising general purpose processors (GPPs) that can be accessed through FH services supported by the transport network of the 5G infrastructure [1]

Summary

Introduction

To address the computational complexity of the ILP, a heuristic algorithm was developed, with the aim to assign the construction elements of the BBU chain to the suitable servers hosted by the CU with minimum power consumption. Compute resources comprise a set S of S GPPs with individual processors of processing capacity Cs and performance per watt (measured in instructions per second—IPS) Ps. Servers are interconnected in accordance to a simple tree structure shown in Fig. 1 and are responsible to provide the required processing power for the support of FH services.

Objectives

Results

Conclusion