The article proposes an algorithm for intelligent traffic routing to control the packets flow and avoid traffic congestion in the Wireless Sensor Networks (WSN) indoors, while improving the Quality of Service (QoS). The article presents the results of research on the analysis of radio signal propagation inside the building in comparison with the propagation in conditions of an unrestricted environment outside the building. At a time an experiment, the correction factor was evaluated to calculate network reliability. These barriers create a heterogeneous environment for the distribution of radio signals. The article investigates and analyzes the impact of radio waves propagation conditions on wireless networks with antennas located at low altitudes and various environmental conditions. The results of experiments show the influence of structural materials and individual elements of the building structure on the nature of radio emission propagation.