A user equipment (UE) is operated in a cellular communication system in which radiofrequency resources are partitioned into layers, each layer being associated with one of a set of hierarchical priority levels. While camped on a serving cell whose signals are transmitted on a first layer associated with a first priority level, the UE repeatedly measures a characteristic of a second layer that is present within its surroundings and generates from these measurements a plurality of measured surroundings data, wherein the second layer is associated with a second priority level that is higher than the first priority level. The UE ceases measuring the characteristic of the second layer that is present within the UE's surroundings in response to detecting both that at least one of the measured surroundings data is less than a predetermined threshold level and that a trend of the measured surroundings data is negative.