A method for attaching a relay module to a fire hydrant comprises positioning the relay module adjacent to the fire hydrant, the fire hydrant comprising a hydrant body and a bonnet coupled to the hydrant body by a plurality of fasteners, the bonnet mounted on top of the hydrant body, the relay module comprising a radio housing defining a top surface, a mast connected to the radio housing and extending upwards from the top surface, and a mounting bracket attached to the top surface, the mounting bracket engageable with the hydrant body; and securing the relay module to the fire hydrant such that the mounting bracket and a portion of the top surface is positioned beneath the bonnet.