隧道环境对可靠的无线通信网络的需求是巨大的，这意味为了提供更好的服务，网络需要具有可监测，安全和流量控制的特点。由于受到波导效应的影响，隧道环境往往复杂且受到各种条件的制约。在不同的陆路介质中，隧道中的无线信号具有不同的衰减系数和传播效果，所以，在优化无线通信网络之前，模型化隧道特点是至关重要的。首先，本文将研究隧道网络的主要信道特性，以分析射频网络在2.4GHz，3.5GHz和5.8GHz等不同频率下的射频信号传播。为了比较不同频率在隧道中的性能，本文会计算每种情况下的衰减情况。其次，本文研究了接收端的信号强度，以验证隧道中基于射频的无线网络的可行性。隧道表面大多是粗糙的，因此还将对衍射损耗进行建模以分析隧道拐角附近的信号损耗。为了分析隧道中的光无线通信的性能，本文将在设定的距离处计算信号强度，以检查光无线通信在隧道中的可行性。最后，提出了一种基于射频和光链路的混合系统，并在隧道环境下对射频和光网络的性能进行了比较。为了克服由于不同的衰减系数而导致的数据丢失问题，当一个通道观测到信号丢失而其他通道正常工作时，混合射频/光学系统将发挥作用，保持通道的一致性。实验证明，该混合系统是改善地下隧道网络通信的理想选择。

There is a huge demand of reliable wireless communication networks in tunnels to provide surveillance, security, traffic control and to provide better services. The tunnel environment is confined and unique because of its waveguide effects. Wireless signals in tunnel can face different kind of degrading parameters and signal propagation in WUCN is significantly different from terrestrial medium. Prior to optimize the wireless propagation, it is basically significant to model channel characteristics in tunnel environment. Firstly this thesis will investigate the major channel characteristics of a tunnel network to analyze the RF signal propagation in tunnel network at different high frequencies like 2.4GHz, 3.5GHz and 5.8GHz. Path loss will be calculated on reference attenuation in tunnel environment to compare the performance of multiple high frequencies.  Furthermore this paper investigates the signal strength on the receiver side to verify the viability of the RF based wireless link in tunnel. Tunnel surface is mostly rough so the diffraction loss will also be modeled to analyze the signal loss around the corners in tunnels. Additionally the performance of optical wireless communication (OWC) in tunnel is examined. For this purpose the signal strength will be calculated at reference distance to inspect the feasibility of OWC in tunnels. Finally a hybrid system is proposed based on RF and optical links for tunnel medium and the performance comparison of RF and Optical network will be done in tunnel. To overcome the problem of data loss because of different degrading parameters the hybrid RF/Optical system will play its role to maintain the consistency of the link when one channel observes loss of signals then other will work. This system could be the great choice for better communication of networks in underground tunnels.