Performance Evaluation of LTE and Wi-Fi Coexistence in Unlicensed Bands

TLDR

Spectrum scarcity and the proliferation of diverse wireless technologies, including small cells and Wi‑Fi, have intensified the need to study coexistence in shared frequency bands. This study evaluates the performance of LTE and Wi‑Fi coexistence and identifies the challenges each technology faces. The authors use a simulator‑based system‑level analysis of an office scenario to assess network performance. Simulation results show that LTE performance is only slightly degraded, whereas Wi‑Fi is severely impacted—its channel is blocked by LTE >96% of the time, reducing throughput by 70–100%—and the study highlights key coexistence issues and mitigation strategies.

Abstract

The deployment of modern mobile systems has faced severe challenges due to the current spectrum scarcity. The situation has been further worsened by the development of different wireless technologies and standards that can be used in the same frequency band. Furthermore, the usage of smaller cells (e.g. pico, femto and wireless LAN), coexistence among heterogeneous networks (including amongst different wireless technologies such as LTE and Wi-Fi deployed in the same frequency band) has been a big field of research in the academy and industry. In this paper, we provide a performance evaluation of coexistence between LTE and Wi-Fi systems and show some of the challenges faced by the different technologies. We focus on a simulator-based system- level analysis in order to assess the network performance in an office scenario. Simulation results show that LTE system performance is slightly affected by coexistence whereas Wi-Fi is significantly impacted by LTE transmissions. In coexistence, the Wi-Fi channel is most often blocked by LTE interference, making the Wi-Fi nodes to stay on the LISTEN mode more than 96% of the time. This reflects directly on the Wi-Fi user throughput, that decreases from 70% to ≈100% depending on the scenario. Finally, some of the main issues that limit the LTE/Wi-Fi coexistence and some pointers on the mutual interference management of both the systems are provided.