Cell-Free Massive MIMO With Segmented Fronthaul: Reliability and Protection Aspects

Cell-free (CF) massive multiple-input multiple-output (mMIMO) networks are envisioned to support fifth-generation (5G) and beyond mobile networks. A proposed economically scalable solution to deploy them is a compute-and-forward architecture, where fronthaul links serially interconnect access points (APs), an alternative called CF mMIMO with segmented fronthaul. However, serial connections can cause reliability issues. This letter analyzes the impact of individual and cumulative failures on APs and fronthaul segments in CF mMIMO with segmented fronthaul using Markov chain Monte Carlo simulations. Our results show that possible failures in segmented fronthaul cannot be neglected and that protection schemes can strongly mitigate their impacts.