A monopole-streetlight assembly includes: an elongate monopole having lower and upper ends; a module configured for mounting of telecommunications antennas; the module including an upper plate and a central spine having an upper end that extends above the upper plate; an adapter having a lower sleeve that receives the upper end of the spine and a flange that extends radially outwardly from the sleeve; and a luminaire unit having an arm having a base, the base being secured to the adapter flange, and further having a luminaire mounted opposite the base.