The number of patents related to the Internet of Thing is on an upward swing.

There are more than 8,500 patent applications mentioning Internet of Things use cases so far, according to an analysis of U.S. patent applications conducted by VDC Research Group.

Of those, 1,900 have been granted, with the number of patents granted for IoT inventions growing each year, from 2014 (25), 2015 (107), 2016 (368) and last year (1,334).

There are four main categories of IoT patents granted, according to the VDC study. The four are communications and networking, cloud services or data handling, physical devices and software solutions. The average patent takes more than two years from the application date until the patent is granted.

Cisco has the most Internet of Things patents (200), followed by Samsung (151), Intel 136), Qualcomm (96) and IBM (72).  Amazon has 22 IoT patents and Google has 21.