The L band, as defined by the IEEE, is the 1 to 2 GHz range of the radio spectrum.

In Europe, the Electronic Communications Committee (ECC) of the European Conference of Postal and Telecommunications Administrations (CEPT) has harmonized part of the L-band (1452-1492 MHz), allowing individual countries to adopt this spectrum for terrestrial mobile/fixed communications networks supplemental downlink (MFCN SDL). By means of carrier aggregation, an LTE-Advanced or UMTS/HSDPA base station could use this spectrum to provide additional bandwidth for communications from the base station to the mobile device, i.e. in the downlink direction.