Connectivity of Wireless Networks Assisted by Transmissive Reconfigurable Intelligent Surfaces

As the core technology of 5G and 6G mobile communication networks, millimeter wave communication is subject to high path loss and limited coverage. The reconfigurable intelligent surface (RIS) is envisioned to circumvent those challenges. However, it remains open to quantify the improvement on the connectivity of the network assisted by RISs. In this paper, we study the connectivity in the network assisted by transmissive RISs, where nodes are equipped with the directional antenna for narrow beam communication over the millimeter wave frequency. Given RISs deployed on the edge of the transmission footprint where the signal is rather weak and needs enhancement, we derive the upper and lower bounds on the critical density of nodes based on the percolation theory to achieve seamless connectivity. Our results provide insights into cost-effective deployment schemes for networks assisted by transmissive RISs, which have been rarely investigated.