This paper investigates the impact of radio irregularity on communication performance in wireless sensor networks. Radio irregularity, caused by factors such as non-isotropic path loss and heterogeneous sending power, leads to asymmetric links and affects MAC and routing protocols. The authors propose a Radio Irregularity Model (RIM) to simulate and analyze these effects. The RIM model accounts for non-isotropic properties of the propagation media and device heterogeneity. Experiments using the MICA2 platform show that received signal strength varies with direction, and packet loss is direction-dependent. The RIM model is used to evaluate the impact of radio irregularity on MAC and routing protocols. Results show that routing protocols are significantly affected, while MAC protocols are less so. The authors propose six solutions to mitigate radio irregularity, including Symmetric Geographic Forwarding and Bounded Distance Forwarding. These solutions improve communication performance in the presence of radio irregularity. The study highlights the importance of modeling radio irregularity in simulations and the need for protocols that can handle asymmetric links.This paper investigates the impact of radio irregularity on communication performance in wireless sensor networks. Radio irregularity, caused by factors such as non-isotropic path loss and heterogeneous sending power, leads to asymmetric links and affects MAC and routing protocols. The authors propose a Radio Irregularity Model (RIM) to simulate and analyze these effects. The RIM model accounts for non-isotropic properties of the propagation media and device heterogeneity. Experiments using the MICA2 platform show that received signal strength varies with direction, and packet loss is direction-dependent. The RIM model is used to evaluate the impact of radio irregularity on MAC and routing protocols. Results show that routing protocols are significantly affected, while MAC protocols are less so. The authors propose six solutions to mitigate radio irregularity, including Symmetric Geographic Forwarding and Bounded Distance Forwarding. These solutions improve communication performance in the presence of radio irregularity. The study highlights the importance of modeling radio irregularity in simulations and the need for protocols that can handle asymmetric links.