The present paper investigates performance of flexible fiber Bragg grating (FBG) sensors network model designed in VPItransmissionMaker simulation software. We report on five optical temperature sensors network based on FBG gratings with different central Bragg reflection wavelength values and standard ITU-T G.652 single mode fiber (SMF) fiber spans. We have used amplified spontaneous emission (ASE) source as low-cost incoherent broadband light source in our network model and optical spectrum analyzer for interrogation of sensors’ signals. In this paper it is shown, that it is important to evaluate FBG sensors’ central Bragg reflection wavelengths and bandwidth of reflected signals, to avoid the spectral overlapping of adjacent sensors, while to be sure that each sensor is working in its assigned wavelength slot. As the spacing between FBG sensors in optical spectrum has an important role on the performance of the whole sensor network, we have investigated minimal spacing intervals for FBG temperature sensors operating in temperatures range from −20 °C up to +40 °C under different scenarios.