Bluetooth 4.2 offered numerous new features for IoT, security, faster speed and more capacity.
For IoT, Bluetooth 4.2 added Bluetooth Smart Internet gateways, which enables Bluetooth 4.2 devices a bridge to the internet. With the internet gateways, Bluetooth 4.2 also added IPv6/6LoWPAN, which enables IPv6 support over a Bluetooth connection.
Bluetooth 4.2 also added extra security with LE Privacy 1.2. The encryption standards with Bluetooth 4.2 comply with the Federal Information Processing Standards (FIPS), which is a US Government computer security standard.
The transmission packet size was increased by ten times as well. This allows for faster and more reliable data transmissions.