A user equipment (2) has an ability to operate according to one or more spectrum emission requirement capability values (14) in a wireless communications network having at least a first serving cell (4). A message (6) is received at the user equipment (2) from the first serving cell (4) comprising a first indicator representing a first band designation (8), a second indicator representing a spectrum emission requirement value (10), and at least one additional indicator representing at least one additional spectrum emission requirement value (12), both the first and additional indicators relating to the first band designation. The user equipment (2) performs a comparison of the first and additional spectrum emission requirement values (10, 12) with the one or more spectrum emission requirement capability values (14) and determines a behavior of the user equipment (2) in relation to the first serving cell (4) in dependence on the comparison.