Sprint Spark Band 41 Carrier Aggregation (2x CA) is officially live according to an internal Sprint document leaked on Reddit this week by a verified Sprint employee. In English, Sprint fully integrated band 41 (aka 2500MHz or 2.5GHz) for Sprint Spark, which, when paired with 800MHz and 1900MHz bands provides notably faster speeds for Sprint customers that have a tri-band capable device.

At the moment there's only seven devices that can take advantage of these faster speeds, including the Samsung Galaxy S6, Samsung Galaxy S6 Edge, Samsung Galaxy Note Edge, LG G Flex 2, LG G4, HTC One M9 and ZTE Hot Spot.

These devices will receive an over the air update to enable the faster speeds.

Theoretical top speeds for fully upgraded Spark deployments are around 150 Mbps, though notably slower in the real world. Sprint needs all the help it can get, given the carrier has shown up in last place in most network speed and performance surveys (though there has been improvement).

According to the leaked internal document, early deployment trial markets included Atlanta, Houston, Chicago and Detroit, with thirty-five additional markets now joining the launch. Sprint has yet to formally announce the launch at the Sprint website.