Model for estimating the throughput of 5G NR backhaul networks

Abstract

Currently, the fifth generation of mobile communication systems of the 5G NR standard are being introduced all over the world. One of the most important components of these systems are backhaul transport networks connecting the base station and the core of the network. The bandwidth of these networks must be sufficient to carry a large amount of traffic. In this article, we propose a mathematical model for calculating the throughput of backhaul networks, which can be used in the design of 5G infrastructure. We also consider some important aspects of the 5G architecture, which make fundamental differences from communication networks of previous generations. One of these aspects is the use of distributed base stations, in which radio signal processing units, low-level and high-level protocol processing units are separated not only logically, but also physically, and can also be spatially separated. Thus, 5G systems fit into the concept of cloud networks, due to which it is possible to significantly save resources for infrastructure deployment. However, such a solution increases the requirements for transport networks. Possible approaches to the physical implementation of transport networks are considered, including a fundamentally new solution that integrates radio access and backhaul networks. Finally, taking into account these and other factors, a mathematical model created by us for estimating the required bandwidth of backhaul networks is described. The model is based on calculating the maximum network load in a base station cell, taking into account such parameters as the number of spatial beams, the aggregated number of subcarriers, modulation index, coding rate, etc. The distributed structure of the base station is also taken into account in the model. Three scenarios of 5G base station operation are shown and an estimate of the required throughput of backhaul networks is given for them.