Establishment of Wi-Fi Display session between source and sink device in wireless Android screencasting

Wireless technology has been rapidly developing. Wi-Fi Alliance several years ago presented Wi-Fi Direct, a new feature that makes it possible to connect devices using ad-hoc network. Since then this technology has been developed and now comes Wi-Fi Display (WFD). This technology is utilized to implement the system of wireless Android screencasting. This system will cast/mirror the Android screen to other screen using a wireless connection. To establish the WFD session, there are respectively two processes: The Wi-Fi Direct connection establishment and the negotiation process.