Ultra wideband over fiber (UWBoF) systems have been proposed to extend wireless range and to interconnect stand‐alone UWB networks. These systems have focused on high‐data‐rate applications. However, UWB will be a key enabler for low‐data‐rate wireless sensor network (WSN) deployments. In this letter, a low‐cost and low‐complexity M‐ary pulse position modulation (PPM) impulse radio (IR)‐UWBoF system designed for WSNs applications is proposed. A spectral line‐suppressive convolutional code is used to achieve spectral line suppression in the power spectral density (PSD). Experimental results show that the system does not distort or add spectral lines to the IR‐UWB signal PSD transmitted over 30 km of a single‐mode fiber, thus demonstrating its feasibility to interconnect WSN deployments