Channel Access in Wireless Smart Grid Networks Operating under ETSI Frame-Based Equipment Rules

Smart grid operators seeking to extend their wireless network capacity can use unlicensed bands. However, devices in these shared bands must follow rules such as Listen Before Talk (LBT), standardized by ETSI. In this paper, we focus on the performance of the frame-based equipment (FBE) version of LBT channel access. We design, implement, and validate a fully functional FBE channel access simulator. Next, we conduct an extensive performance analysis of the FBE variants encountered in the literature, focusing on channel efficiency and fairness in upper-bound and coexistence scenarios. Our study leads to several conclusions about the operation of FBE-based devices, including the need for proper configuration of channel access parameters to ensure fairness and optimal performance. We also observe generally poor coexistence among FBE variants: the highest Jain's fairness index was only 0.88, with an average normalized channel efficiency of 0.76. Therefore, we identify several open research areas in the field, such as the need for further development of parameter adaptation algorithms, the deployment of an external controller to update channel access parameters, and new FBE designs with better coexistence qualities.