1. A method performed by a mobile device comprising: receiving a plurality of measurements corresponding to operation of a first radio interface; normalizing each of the plurality of measurements to produce a plurality of normalized measurements; weighting each of the plurality of normalized measurements to produce a plurality of weighted normalized measurements; summing the plurality of weighted normalized measurements to form a composite quality measure for the first radio interface; receiving a second plurality of measurements corresponding to operation of a second radio interface; normalizing each of the second plurality of measurements to produce a second plurality of normalized measurements; weighting each of the second plurality of normalized measurements to produce a second plurality of weighted normalized measurements; and summing the second plurality of weighted normalized measurements to form a composite quality measure for the second radio interface.