Abstract: A tintable window is described having a tintable coating, e.g., an electrochromic device coating, for regulating or blocking light transmitted through the window. In some embodiments, the window can receive, transmit and/or regulate wireless communication that uses electromagnetic waves as a communication medium. In some cases, a window can receive or transmit infrared, visible, or ultraviolet wireless light fidelity (LiFi) signals. A window can be configured, in some cases selectively configured, for blocking radiation and/or signals generated by LiFi, radio frequency (RF), laser or other devices from passing through the window. Windows configured for blocking signals may be configured as a communication firewall between an interior environment and an exterior environment, or vice-versa. Networks of tintable windows can communicate via LiFi and provide a communications network through which other devices, such as personal computing devices, can be connected to the internet or a remote network.