A system is described that utilizes the measured characteristics of a cell site or a plurality of cell sites (100, 102, 104) and the cellular identification to selectively provide a wireless device (118) with location aiding from a cellular network server (120). The system may include a basestation (106, 108, 110) located within the cell site, a cellular measurement unit located in the wireless device (118), and a database (214) containing positional assistance information corresponding to the characteristic information. The system may also include a processing unit in signal communication with the basestation and the database (214) and a positional determination unit in the wireless device (118).