As availability of virgin spectrum in the ‘ideal’ cellular bands between about 600MHz and 2.5GHz dries up, the cellcos will increasingly have to rely on building a messy patchwork of airwaves, including frequencies well above that 2.5GHz ceiling; refarmed, leased or shared spectrum; and the unlicensed wilderness as well. To turn the patchwork into a coherent whole, the key tool will be standards-based carrier aggregation, as supported in LTE-Advanced specifications. This promises to turn undesirable bands, unusable slivers and scattered fragments of spectrum into a seamless pool of capacity ‘ though of course, for the sake of a viable handset ecosystem, there will need to be some compromises in order to create a ‘common set’ of combinations that will feature…