Advanced multiple antenna technique that increases the spectral efficiency, range and bandwidth available to moving wireless devices. Traditional cellular base stations radiate power in all directions, because they have no information about where the mobile device is located. This wastes power and causes interference to adjacent cells, as well as making it harder to distinguish weaker incoming signals from among the noise and interference. By using smart antenna technology to track the spatial location of mobile devices, the radiation pattern of the base station can be adjusted to optimize both transmission and reception for each user device. By rapidly adjusting the phase of signals from several antennas, the base station can effectively steer a beam or a spot of RF power to or from each user. Unlike MIMO, only one antenna is required at the client device, potentially reducing customer premises equipment (CPE) costs. SDMA techniques are used in proprietary wireless broadband systems and are likely options for mobile WiMAX and LTE. See also smart antenna.