The protocols have evolved over the past decade, too. After the initial protocols stabilized, higher data rates were added to Bluetooth 2.0 in 2004. With the
3.0 release in 2009, Bluetooth can be used for device pairing in combination with
802.11 for high-throughput data transfer. The 4.0 release in December 2009 specified low-power operation. That will be handy for people who do not want to
change the batteries regularly in all of those devices around the house. We will
cover the main aspects of Bluetooth below.