After recently reporting about the current state of LTE carrier aggregation the technology circus has moved on again and hype is building up aground aggregating 3 component carriers in three different bands. Here's a report over at Lightreading that SK Telecom in Korea is undertaking first preparations on the network side for aggregating spectrum in three different bands (800 MHz (band ?), 1800 MHz (band 3), 2100 MHz (probably band 1)) for a total bandwidth of 40 MHz.
As there are only few devices and networks out in the wild so far that bundle two component carriers (such as AT&T aggregating 10 MHz and 5 MHz in two different bands) I don't expect to see devices soon that support reception on three different bands simultaneously.But in any case an interesting development to see. Apart from a higher theoretical maximum throughput, 3 band carrier aggregation with such diverse bands cold potentially bring interesting benefits in scenarios where a user frequently moves indoors and outdoors and thus is sometimes better served on a higher or on a lower band. Sure, inter-frequency handovers can also do the trick, but perhaps there's an advantage with carrier aggregation as fewer break and make handovers are required.