This specification describes the functionality and interfaces of an Internet Protocol (IP)-based wireless communications system between an aircraft on the ground and a ground-based network using Wireless Local Area Network (WLAN) and/or cellular radios and protocols. The ground-based network will be primarily used to provide connectivity to an airline's back office or to its back-end maintenance systems although other uses are also possible when there is a need to transfer data to or from the aircraft's applications while it is taxiing or parked. Gatelink is the accepted industry term for this type of connection. This document is a major revision to ARINC Specification 822 released in 2008.