Analytical Study of Electromagnetic Wave Propagation Characteristics in Tropical Rainforest Environments for Wireless Network Planning in Cross River State

Background: Accurate radio wave propagation modelling in dense tropical rainforest environments is essential for reliable wireless network design in Cross River State, South South Nigeria, where forest canopy strongly attenuates signals but empirical propagation models remain absent. Aim: This study empirically characterised electromagnetic wave propagation in rainforest terrain in Cross River State and developed a site-specific path loss model. Methods: Field measurements of received signal strength were conducted at 850 MHz, 1800 MHz, and 2.4 GHz frequencies across 45 forest transects of varying vegetation density using a calibrated spectrum analyser and reference transmitter. Path loss exponents and shadowing standard deviations were extracted by regression analysis and compared with standard propagation models. Results: Measured path loss exponents ranged from 3.8 to 5.6 depending on frequency and vegetation density, substantially higher than open terrain values. Standard models including Okumura-Hata and COST-231 underestimated path loss by 12 to 22 dB. A modified vegetation-weighted path loss model reduced prediction error to below 4 dB. Conclusion: Existing propagation models are inadequate for rainforest environments in Cross River State. The developed model provides more accurate guidance for network planning. Keywords: electromagnetic wave propagation, rainforest, path loss model, Cross River State, wireless networks.