The telecommunications data transfer in singlemode (SM) optical fiber (OF) of a passive optical network (PON) is managed by dynamic bandwidth allocation (DBA). In most internet of things (IoT) sensor network applications, both raw sensing signals and telecommunication data are transmitted in SM OFs, too. At the present time, this is not done in a shared SM OF. This paper presents a novel concept to share FBG sensing and telecommunication services (TS) in the optical C-band of the shared transmission. This concept is based on statistical detection and monitoring of fiber Bragg gratings (FBGs) sensing signals. The key steps of the proposed concept are FBG power spectral peaks statistical detection, monitoring of the FBGs dynamics and periodical estimation of TChs occupancy and availability. The proposed concept was demonstrated and validated using sensor network with a deployed group of FBG-based sensors, by implementing various static or dynamic approaches. By doing so, we achieved telecommunication channels (TChs) bandwidth availability approaching 80 %, compared to previously wasted bandwidth with availability at most 15.6 %. Experimental results showed that a DBA system with implemented dynamic TChs occupancy is a reliable way to share fiber bandwidth between both FBG sensing and TChs.